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Thread: The definitive subframe strategy thread

  1. #901
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    Quote Originally Posted by Reddy Kilowatt View Post
    ^ This was intended to do just that, though perhaps it's missing basic and detailed descriptions of the problem.
    Nice cheat sheet, but I think we need something really basic and clear in a single post that all can agree with, that is unavoidable, and that catches a noob's attention right off the bat without requiring any work on their part. Maybe titled "WARNING READ THIS POST BEFORE BUYING A Z3--IGNORE AT YOUR OWN RISK" and reading something like this:

    WARNING--(we love our cars, but)--THERE IS A DESIGN DEFECT IN THE Z3 YOU NEED TO KNOW ABOUT BEFORE YOU BUY. The Z3 was designed for the 1.9 four cylinder engine. BMW introduced progressively larger displacement/horsepower engines, from the 2.3 six through the final 3.2 ///M version in 01' and 02' developing 315 horsepower. However, BMW did not re-engineer the chassis to handle the additional horsepower. There was also a problem of undetermined origin at the Spartanburg plant that effected the spot welding of the trunk floor. These two issues combined have led to many failed trunk floors, differential mounts, and the cross member that joins them. This issue can lead to a catastrophic failure of the system and effectively destroy your car. These engineering defects and production flaws combined are referred to as the "subframe issue," although they in fact do not involve the subframe directly. The good news is that there is a complete solution. The bad news is that it is very expensive to have done (thousands). There are lesser solutions that cost less. BMW has systematically refused to recognize this issue publicly, although privately they have addressed several instances by replacing the floor, cross member and mount with OEM replacement parts. The OEM replacements also fail. BMW Europe has released a reinforcement, but it is not substantial and doesn't address the whole problem. The definitive and best solution is called the Randy Forbes Subframe Kit (RF kit), and was developed and refined by a fellow member. Randy Forbes is still active--both on the forum and in his shop in Florida. He sells the kits and installs them as well. There are several "certified" RF kit installers throughout the country and across the world--RF can direct you to the nearest one to you. Below are links to threads addressing various points, from inspection, to the RF kit, to all the other options and opinions.

    BE FULLY AWARE OF THE SUBFRAME ISSUE BEFORE YOU BUY A Z3--YOU ARE FOREWARNED.

  2. #902
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    Quote Originally Posted by Reddy Kilowatt View Post
    ^ This was intended to do just that, though perhaps it's missing basic and detailed descriptions of the problem.
    Quote Originally Posted by Reddy Kilowatt View Post
    Cliff Notes!

    This thread is quite long, and many of the photos and links from the early days are broken. The thread is still worth reading in its entirety, but for those who just need to get down to brass tacks, I'm hoping this distillation is helpful. If I've missed any critical information, point it out to me and I can edit it into this post.

    Steps to access trunk floor
    http://forums.bimmerforums.com/forum...&postcount=263

    Diagnosis photos
    http://forums.bimmerforums.com/forum...&postcount=181

    Pictures of asphalt mat removal and re-install
    http://forums.bimmerforums.com/forum...&postcount=755

    Single-ear reinforcement
    http://forums.bimmerforums.com/forum...&postcount=846

    Repair photos & bushing recommendation
    http://forums.bimmerforums.com/forum...&postcount=185

    Link w/ pictures of cars post-repair
    http://forums.bimmerforums.com/forum...&postcount=790

    More repair photos
    http://www.spcarsplus.com/gallery3/i...time-s-a-charm

    California installation
    http://forums.bimmerforums.com/forum...&postcount=778

    Originally posted by Mr Bingley:
    Nice cheat sheet, but I think we need something really basic and clear in a single post that all can agree with, that is unavoidable, and that catches a noob's attention right off the bat without requiring any work on their part. Maybe titled "WARNING READ THIS POST BEFORE BUYING A Z3--IGNORE AT YOUR OWN RISK" and reading something like this:

    WARNING--(we love our cars, but)--THERE IS A DESIGN DEFECT IN THE Z3 YOU NEED TO KNOW ABOUT BEFORE YOU BUY. The Z3 was designed for the 1.9 four cylinder engine. BMW introduced progressively larger displacement/horsepower engines, from the 2.3 six through the final 3.2 ///M version in 01' and 02' developing 315 horsepower. However, BMW did not re-engineer the chassis to handle the additional horsepower. There was also a problem of undetermined origin at the Spartanburg plant that effected the spot welding of the trunk floor. These two issues combined have led to many failed trunk floors, differential mounts, and the cross member that joins them. This issue can lead to a catastrophic failure of the system and effectively destroy your car. These engineering defects and production flaws combined are referred to as the "subframe issue," although they in fact do not involve the subframe directly. The good news is that there is a complete solution. The bad news is that it is very expensive to have done (thousands). There are lesser solutions that cost less. BMW has systematically refused to recognize this issue publicly, although privately they have addressed several instances by replacing the floor, cross member and mount with OEM replacement parts. The OEM replacements also fail. BMW Europe has released a reinforcement, but it is not substantial and doesn't address the whole problem. The definitive and best solution is called the Randy Forbes Subframe Kit (RF kit), and was developed and refined by a fellow member. Randy Forbes is still active--both on the forum and in his shop in Florida. He sells the kits and installs them as well. There are several "certified" RF kit installers throughout the country and across the world--RF can direct you to the nearest one to you. Below are links to threads addressing various points, from inspection, to the RF kit, to all the other options and opinions.

    BE FULLY AWARE OF THE SUBFRAME ISSUE BEFORE YOU BUY A Z3--YOU ARE FOREWARNED.
    I have to agree, it's an overly long thread, and I don't blame anybody for not wanting to read it__it's overwhelming, even if you have a grasp on the condition; I can't imagine what it must be like to read for the newly exposed Z3/M enthusiast!

    I always appreciate Ralph giving me such a glowing review (thanks Ralph, as always!), but I'd understand completely if the moderators wanted to tone it down a bit, and then perhaps make Reddy's and Ralph's posts (above) the "new" trunkfloor/differential mount failure sticky (and locked) thread. There can always be a link to this existing "subframe stategy" thread for those to ask specific questions, and/or willing to read up all that they can.

    If you need any trunkfloor pictures of before or after, I've got them covered!

  3. #903
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    Maybe some others can edit and add to what I wrote, so we get a collective sort of statement, combine that with Reddy's post, a link to the original subframe strategy thread, and some pics from Randy--how about a a couple of diagnosis shots of what to look for when buying, and a couple of really serious floor failure shots--you know, where the diff fins are ground down, and the cross member hangs off the car. I know there are other repair kits out there--I've seen one or two serious ones posted about. And of course there's the IE bushings to write about. I was just ranting when I wrote my proposal, so I'm sure I left out things others want to say, and said things others disagree with. However, lets work constructively on putting together a perfect post and then sticky and lock it, Terry, what do you think--is it time to address this monster thread? If so, maybe you can post the finished product, so there are no credit issues on a collaborative work.

  4. #904
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    Quote Originally Posted by Mr Bingley View Post
    Ok, you need to read this thread--either that or we need a new definitive subframe strategy thread that is easier to plow through--clearly we are not imparting the information we need to. Too many people are not getting what they need to properly understand the subframe/trunk floor/diff mount issue, and the solutions available. 36 pages of material is simply too much for a noob to process before they buy their car. This thread only needs to be one post, or, at most, one page--it needs to be clear, precise, to the point, and definitive. We have done a disservice to the community by letting it go this long. The subframe/trunk floor/diff mount issue is a big deal and people need to be clearly warned and apprised of the options and potential costs associated with those options.

    Ok, rant over--I've just written too many responses lately to questions that could have been asked and answered before purchase.
    Actually, I have read and understand this thread very well. And I don't want to take ANYTHING away from Randy Forbes' excellent work in the subframe issue, but there's more than one way to skin this cat. And in my case I have a 98,000 mile Z3M that shows NO evidence subframe or floor failure. That combined with the fact that I have 30 years automotive fabrication/machining experience, I'm choosing a less invasive route as a preemptive reinforcement. I believe it to be similar to what Randy has done with a single ear double thick modification with some other subframe reinforcements added.

    Now if I was planning to track the car hard, I'd be going the twin-eared route all day and most likely ordering Randy's kit to do that. But fact that ths car has stayed together this long and my purposes don't really warrant massive change, I'm sticking with my planned improvement.
    Z3M Racer '99 M Roadster

  5. #905
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    I just finally fitted Randy's reinforcement this last weekend after having the kit sitting for about a year and recently noting the spot welds starting to go quite badly. The job took pretty much all weekend (Friday eve - Sunday eve) but overall it was quite good fun. I consider it a success, I did start to get some diff whine afterwards (and started worrying that I'd botched the angles despite all my efforts) although I just got back from a diff specialist who had a look and told me the angles were good (based on no vibration) and I'd probably misaligned something internally when swapping out the impulse wheel. Looking back we did have a crazy time trying to press the new impulse wheel on so I guess it makes sense. Either way I reckon its another Z3 M saved from the scrapyard with the new diff all in place. I'd put my total out of pocket at around $2k spread out a bit. ~$550 on the kit, ~$500 for a welder to come help us out for a day, ~$500 is miscellaneous parts, tools e.t.c. and $125 for a TechShop membership for a month to give us a location to get the work done.

    - - - Updated - - -

    Anyway, now I have an excuse to go back into the diff and change the final drive

  6. #906
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    Quote Originally Posted by GBPaterson View Post
    I did start to get some diff whine afterwards (and started worrying that I'd botched the angles despite all my efforts) although I just got back from a diff specialist who had a look and told me the angles were good (based on no vibration) and I'd probably misaligned something internally when swapping out the impulse wheel.
    I think a lot of the increased noise is the metal/metal contact of the e36 cover and the RF diff ears. I noticed it as well, and I'm pretty sure my diff is fine.
    The OE single ear was double-shear, so the bushing completely isolated the diff from the trunk floor. The RF kit is much stronger and stiffer, but it also contacts the diff directly in single-shear, so you're going to get more mechanical noise transmitted.
    I'm confident it's nothing to worry about.

  7. #907
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    Ok, well nobody has taken up the challenge of helping to draft a new subframe sticky that is more accessible and to the point, so I am trying again. I can understand that Randy won't contribute--he has a pecuniary interest and has the good taste to stand back from what might be perceived as advertising. But I cannot believe that the subject is without controversy, and I still think that a collaborative effort is worth a try. So, that being said, I am looking for contributions, criticisms, deletions, edits, etc., to what I started earlier and repeat below (edited), as a proposed replacement subframe (trunk floor/diff mount) sticky (and locked) thread to put noobs and shoppers on notice of the problem and solutions, without having to digest 37 pages of densely packed material. I propose this as a start--the links and photos need to be added, and the whole edited, revised and added to.

    (Revised) proposed title:

    WARNING TRUNK FLOOR/DIFFERENTIAL MOUNT (SUBFRAME) FLAW--READ THIS POST BEFORE BUYING, IF YOU JUST BOUGHT, OR IF YOU DON'T KNOW ABOUT THIS" and reading something like this:

    (Revised body):

    WARNING--(we love our cars, but)--THERE IS A DESIGN AND/OR MANUFACTURING DEFECT IN THE Z3 YOU NEED TO KNOW ABOUT BEFORE YOU BUY, OR IF YOU ALREADY OWN A Z3, YOU MUST BE FULLY AWARE OF THIS ISSUE.

    The Z3 was designed for the 1.9 four cylinder engine. BMW introduced progressively larger displacement/horsepower engines, from the 2.3 six through the final 3.2 s54 ///M version in 01' and 02' developing 315 horsepower. However, BMW did not re-engineer the chassis to handle the additional horsepower. There was also a problem of undetermined origin at the Spartanburg plant that effected the spot welding of the trunk floor and frame crossmember. These two issues combined have led to many failed trunk floors, differential mounts, and the frame cross member that joins them. This issue can lead to a catastrophic failure of the system and potentially destroy your car, leading to cost prohibitive repairs into the many thousands of dollars.

    These engineering defects and production flaws combined are referred to as the "subframe issue," although they in fact do not involve the subframe directly. The good news is that there are complete solutions. The bad news is that they can be very expensive to have done (thousands). There are also lesser solutions that cost less.

    BMW North America has systematically refused to recognize this issue publicly, although privately they addressed several instances by replacing the floor, cross member and mount with OEM replacement parts. The OEM replacements also fail. BMW Europe has released a reinforcement, but it is not substantial and doesn't address the whole problem.

    By universal recognition in this and other forums, the definitive and best solution is called the Randy Forbes Subframe Kit (RF kit), and was developed and refined by fellow member Randy Forbes, who remains active--both on the forum and in his shop in Florida. He sells his kits and installs them as well. The kit is a steel weld in reinforcement of the cross member and floor, and redesign of the differential mounting system. There are several "certified" RF kit installers throughout the country and across the world--RF can direct you to the nearest one to you. There are other weld-in solutions and kits, and links to these are provided below, but they are universally recognized as being less effective than the RF kit.

    It is generally agreed that a part of the overall problem (and this does involve the subframe) is that the subframe bushings mounting the subframe to the body are too soft, allowing too much play, and placing an undue stress on the differential mount. There are polyurethane subframe bushings available in the aftermarket to address this aspect of the problem, with the Ireland Engineering (IE) bushings being generally recognized as the best option. Many believe, and there is anecdotal evidence to back this up, that going to the IE poly subframe bushings can prevent the problem from developing in the first place.

    The problem appears in one of two (or a combination of both) forms: spot welds in the trunk "popping," and stress cracks in the differential mount. Below are pictures of the differential mount, and what to look for there, and also are pictures of spot welds popping, and what to look for in the trunk. You can also see pictures of what it looks like when the system fails.

    There is a school of thought that advocates reinforcing the first popped spot weld or two in an effort to stave off the problem. There are links to this discussion included below as well.

    There is a long standing decade old and many many page thread called the "Definitive Subframe Strategy Thread" that documents the growing awareness of the problem, BMW's shirking of it, and the development process that led to today's solutions. Feel free to post in that thread, it is a living evolving thread and an active discussion--this post was developed in that thread and is intended to put you on notice of the problem, how to diagnose it, fix it, and possibly avoid it.

    Below are links to threads addressing various points, from inspection, to the RF kit, to all the other options and opinions. Also following are various pictures you need to reference to thoroughly understand and diagnose the issue (or lack of it).

    BE FULLY AWARE OF THE SUBFRAME ISSUE BEFORE YOU BUY A Z3.

  8. #908
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    Quote Originally Posted by Mr Bingley View Post
    Ok, well nobody has taken up the challenge of helping to draft a new subframe sticky that is more accessible and to the point, so I am trying again. I can understand that Randy won't contribute--he has a pecuniary interest and has the good taste to stand back from what might be perceived as advertising. But I cannot believe that the subject is without controversy, and I still think that a collaborative effort is worth a try. So, that being said, I am looking for contributions, criticisms, deletions, edits, etc., to what I started earlier and repeat below (edited), as a proposed replacement subframe (trunk floor/diff mount) sticky (and locked) thread to put noobs and shoppers on notice of the problem and solutions, without having to digest 37 pages of densely packed material. I propose this as a start--the links and photos need to be added, and the whole edited, revised and added to.

    (Revised) proposed title:

    WARNING TRUNK FLOOR/DIFFERENTIAL MOUNT (SUBFRAME) FLAW--READ THIS POST BEFORE BUYING, IF YOU JUST BOUGHT, OR IF YOU DON'T KNOW ABOUT THIS" and reading something like this:

    (Revised body):

    WARNING--(we love our cars, but)--THERE IS A DESIGN AND/OR MANUFACTURING DEFECT IN THE Z3 YOU NEED TO KNOW ABOUT BEFORE YOU BUY, OR IF YOU ALREADY OWN A Z3, YOU MUST BE FULLY AWARE OF THIS ISSUE.

    The Z3 was designed for the 1.9 four cylinder engine. BMW introduced progressively larger displacement/horsepower engines, from the 2.3 six through the final 3.2 s54 ///M version in 01' and 02' developing 315 horsepower. However, BMW did not re-engineer the chassis to handle the additional horsepower. There was also a problem of undetermined origin at the Spartanburg plant that effected the spot welding of the trunk floor and frame crossmember. These two issues combined have led to many failed trunk floors, differential mounts, and the frame cross member that joins them. This issue can lead to a catastrophic failure of the system and potentially destroy your car, leading to cost prohibitive repairs into the many thousands of dollars.

    These engineering defects and production flaws combined are referred to as the "subframe issue," although they in fact do not involve the subframe directly. The good news is that there are complete solutions. The bad news is that they can be very expensive to have done (thousands). There are also lesser solutions that cost less.

    BMW North America has systematically refused to recognize this issue publicly, although privately they addressed several instances by replacing the floor, cross member and mount with OEM replacement parts. The OEM replacements also fail. BMW Europe has released a reinforcement, but it is not substantial and doesn't address the whole problem.

    By universal recognition in this and other forums, the definitive and best solution is called the Randy Forbes Subframe Kit (RF kit), and was developed and refined by fellow member Randy Forbes, who remains active--both on the forum and in his shop in Florida. He sells his kits and installs them as well. The kit is a steel weld in reinforcement of the cross member and floor, and redesign of the differential mounting system. There are several "certified" RF kit installers throughout the country and across the world--RF can direct you to the nearest one to you. There are other weld-in solutions and kits, and links to these are provided below, but they are universally recognized as being less effective than the RF kit.

    It is generally agreed that a part of the overall problem (and this does involve the subframe) is that the subframe bushings mounting the subframe to the body are too soft, allowing too much play, and placing an undue stress on the differential mount. There are polyurethane subframe bushings available in the aftermarket to address this aspect of the problem, with the Ireland Engineering (IE) bushings being generally recognized as the best option. Many believe, and there is anecdotal evidence to back this up, that going to the IE poly subframe bushings can prevent the problem from developing in the first place.

    The problem appears in one of two (or a combination of both) forms: spot welds in the trunk "popping," and stress cracks in the differential mount. Below are pictures of the differential mount, and what to look for there, and also are pictures of spot welds popping, and what to look for in the trunk. You can also see pictures of what it looks like when the system fails.

    There is a school of thought that advocates reinforcing the first popped spot weld or two in an effort to stave off the problem. There are links to this discussion included below as well.

    There is a long standing decade old and many many page thread called the "Definitive Subframe Strategy Thread" that documents the growing awareness of the problem, BMW's shirking of it, and the development process that led to today's solutions. Feel free to post in that thread, it is a living evolving thread and an active discussion--this post was developed in that thread and is intended to put you on notice of the problem, how to diagnose it, fix it, and possibly avoid it.

    Below are links to threads addressing various points, from inspection, to the RF kit, to all the other options and opinions. Also following are various pictures you need to reference to thoroughly understand and diagnose the issue (or lack of it).

    BE FULLY AWARE OF THE SUBFRAME ISSUE BEFORE YOU BUY A Z3.
    Succinct. I can think of nothing that needs to be added nor taken away.

    I'm sure that TerryF. will come across this on his own, but perhaps a PM request to sticky/lock Ralph's polished version, with the aforementioned links added to the existing thread.

    I'll contribute a couple of pictures to point out where an owner, or potential owner, should be looking for first signs of trouble__naturally, my pictures will show advanced stages of damage, but should serve to show all or most of the problem areas.





    I have more, if they're deemed necessary...

  9. #909
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    Ok, here is a more fleshed out post that can be it's own stand alone sticky and locked thread to replace this one in that position:


    • I propose the title: "Trunk floor/differential mount/subframe flaw"
    • But anything that gets a newbie's attention will suffice.
    • Again, the idea is to distill the current subframe strategy thread to something more accessible and directly to the point.
    • If the Mod (Terry) approves, he can cut and paste it himself to start a new thread posted by him--I am not looking to be the poster--too many people have put way too much work into the subframe strategy thread for that.
    • If anyone has suggestions or comments, please post them.


    The proposed thread:

    WARNING--(we love our cars, but)--THERE IS A DESIGN AND/OR MANUFACTURING DEFECT IN THE Z3 YOU NEED TO KNOW ABOUT BEFORE YOU BUY, OR IF YOU ALREADY OWN A Z3, YOU MUST BE FULLY AWARE OF THIS ISSUE.

    The Z3 chassis was originally designed for the 1.9 M44 four cylinder engine developing 138 horsepower. From 1997 to 2002 BMW introduced progressively larger displacement/horsepower engines, from the 2.5 M52 six developing 170 horsepower through the final 3.2 S54 ///M version in 01' and 02' developing 315 horsepower. However, BMW did not re-engineer the chassis to handle the additional horsepower. There was also a problem of undetermined origin at the Spartanburg plant that effected the spot welding of the trunk floor and frame crossmember. These two issues combined have led to many failed trunk floors, differential mounts, and the frame cross member that joins them to the trunk floor. This issue has led to a catastrophic failure of the system on several Z3's, and can potentially destroy your car, leading to cost prohibitive repairs into the many thousands of dollars.

    These engineering defects and production flaws combined are referred to here as the "subframe issue," although they in fact do not involve the subframe directly. The good news is that there are complete solutions. The bad news is that they can be very expensive to have done (thousands). There are also lesser solutions that cost less.

    BMW North America has systematically refused to recognize this issue publicly, although privately they addressed several instances by replacing the floor, cross member and mount with OEM replacement parts. The OEM replacements also fail. BMW Europe has released a reinforcement, but it is not substantial and doesn't address the whole problem.

    By universal recognition in this and other forums, the definitive and best solution is called the Randy Forbes Subframe Kit (RF kit), and was developed and refined by fellow member Randy Forbes, who remains active--both on the forum and in his shop in Florida. He sells his kits and installs them as well. The kit is a steel weld in reinforcement of the cross member and floor, and redesign of the differential mounting system. There are several "certified" RF kit installers throughout the country and across the world--RF can direct you to the nearest one to you. There are other weld-in solutions and kits, and links to these are provided below, but they are universally recognized as being less effective than the RF kit.

    It is generally agreed that a part of the overall problem (and this does involve the subframe) is that the subframe bushings mounting the subframe to the body are too soft, allowing too much play, and placing an undue stress on the differential mount. There are polyurethane subframe bushings available in the aftermarket to address this aspect of the problem, with the Ireland Engineering (IE) bushings being generally recognized as the best option. Many believe, and there is anecdotal evidence to back this up, that going to the IE poly subframe bushings can prevent the problem from developing in the first place.

    The problem appears in one of two (or a combination of both) forms: spot welds in the trunk "popping," and stress cracks in the differential mount. Below are pictures of the differential mount, and what to look for there, and also are pictures of spot welds popping, and what to look for in the trunk. You can also see pictures of what it looks like when the system fails.

    There is a school of thought that advocates reinforcing the first popped spot weld or two in an effort to stave off the problem. There are links to this discussion included below as well.

    There is a long standing decade old and many many page thread called the "Definitive Subframe Strategy Thread" that documents the growing awareness of the problem, BMW's shirking of it, and the development process that led to today's solutions. Feel free to post in that thread, it is a living evolving thread and an active discussion--this post was developed in that thread and is intended to put you on notice of the problem, how to diagnose it, fix it, and possibly avoid it.

    http://forums.bimmerforums.com/forum...trategy-thread

    Below are links to threads addressing various points, from inspection, to the RF kit, to all the other options and opinions. Also following are various pictures you need to reference to thoroughly understand and diagnose the issue (or lack of it).

    One final note: the problem appears more often in the higher horsepower Z3's (like the ///M's). If you own a 1.9 automatic, it is unlikely that you need to be concerned with this issue. In fact, pretty much any 1.9 or automatic is likely not an issue. Some small number of 2.5's (2.3's) have been reported as having the issue, it is more common, but still rare in 2.8's, increasingly common in 3.0's, and quite common in the 3.2 ///M (both S52 and S54 engines). If you plan on supercharging or turbocharging your Z3 (forced induction, or FI), you need to address this issue first.

    PICTURES (courtesy of Randy Forbes)

    This a typical view of the trunk floor exhibiting spot weld issues:




    Here is a close up of some bad welds, so you know what to look for:



    Here are some stress cracks in a differential mount:



    And here is a total system failure--note that the cross member has completely seperated from the trunk floor and exhibits its own stress cracks--you can see where the spot welds have ripped out of the trunk floor:



    On this example, the differential came down and dragged on the ground, you can see how it looks compared to a good cover:



    There is seam sealer in the trunk, and some models have sound deadening, which can make it difficult to diagnose the problem:



    LINKS TO OTHER THREADS (courtesy of Reddy Kilowatt):

    Steps to access trunk floor
    http://forums.bimmerforums.com/forum...&postcount=263

    Diagnosis photos
    http://forums.bimmerforums.com/forum...&postcount=181

    Pictures of asphalt mat removal and re-install
    http://forums.bimmerforums.com/forum...&postcount=755

    Single-ear reinforcement
    http://forums.bimmerforums.com/forum...&postcount=846

    Repair photos & bushing recommendation
    http://forums.bimmerforums.com/forum...&postcount=185

    Link w/ pictures of cars post-repair
    http://forums.bimmerforums.com/forum...&postcount=790

    More repair photos
    http://www.spcarsplus.com/gallery3/index.php/3rd-time-s-a-charm

    Reinforce the popped weld
    http://forums.bimmerforums.com/forum...-floor-failure

  10. #910
    Terry F.'s Avatar
    Terry F. is offline ONLY BMW Content is + Moderator
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    Please create the new stand-alone thread and I'll pin the new thread and unpin the existing one. I'm asking you guys to do it as I want no credit for any of the effort, it's your baby. I have not ever participated in the existing thread and really don't want to step in now. My only suggestion, a selfish one, is to not make the post too alarmist. Let's try to maintain some level of resale value in our cars. :-)

    Thanks for your efforts,
    Terry

    Stuff. I got stuff.

  11. #911
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    Quote Originally Posted by Terry F. View Post
    Please create the new stand-alone thread and I'll pin the new thread and unpin the existing one. I'm asking you guys to do it as I want no credit for any of the effort, it's your baby. I have not ever participated in the existing thread and really don't want to step in now. My only suggestion, a selfish one, is to not make the post too alarmist. Let's try to maintain some level of resale value in our cars. :-)

    Thanks for your efforts,
    Terry
    Toned down version posted--I hope this meets your concerns.

    Ralph.

  12. #912
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    2000 M Coupe, 318TI
    Quote Originally Posted by Mr Bingley View Post
    The Z3 chassis was originally designed for the 1.9 M44 four cylinder engine developing 138 horsepower. From 1997 to 2002 BMW introduced progressively larger displacement/horsepower engines, from the 2.5 M52 six developing 170 horsepower through the final 3.2 S54 ///M version in 01' and 02' developing 315 horsepower. However, BMW did not re-engineer the chassis to handle the additional horsepower. There was also a problem of undetermined origin at the Spartanburg plant that effected the spot welding of the trunk floor and frame crossmember. These two issues combined have led to many failed trunk floors, differential mounts, and the frame cross member that joins them to the trunk floor. This issue has led to a catastrophic failure of the system on several Z3's, and can potentially destroy your car, leading to cost prohibitive repairs into the many thousands of dollars.
    The history ignores the European cars. Taking the production dates from realoem,

    Engine First Production Month Region
    1.8
    12/1994
    Europe
    1.9
    04/1995
    Europe
    1.9
    07/1995
    USA
    S50
    04/1996
    Europe
    2.8
    04/1996
    USA
    2.8
    07/1996
    Europe
    S54
    07/2000
    USA

    16 months after the first 140 hp Z3 was produced, production started of the 321 hp S50 Z3 M roadster (reviewed in the March 5, 1997 issue of "Autocar"), more than doubling the hp.

    IMHO, the problem is not for 5 1/2 years BMW failed to re-engineer the chassis while fitting progressively larger engines. Rather BMW made the same mistake as was made on the E36 and E46 - both of which have their own cracking chassis problems - simply under engineered the original design.
    Last edited by dougmcintyre; 04-08-2013 at 09:11 AM.

  13. #913
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    Hey Guys, I need a little crowd sourcing help. I'm looking at buying a 1998 Z3 2.8L with 85000km. This subframe problem has me spooked alittle. I would like some opinions. I inspected the car in the sellers driveway today. I couldn't get underneath but did take some pictures in the trunk. I can see one spot weld that looks suspect.
    I was wondering what the sequence of failure is... do the welds in the trunk go first? or is there cracking on the side (under the insulation or under the car) first? and curious as to what repair would be next? Can it be patched now or is this a full repair once at this stage.
    I'll try to attach a photo...
    Thanks for any help.

    https://www.dropbox.com/s/fed3l13592...nk%20welds.JPG
    Last edited by Fudged; 04-21-2013 at 03:49 PM.

  14. #914
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    1998 M Roadster
    Yeah, that's a bad one, the one to the left looks suspect too. That being said, there are several schools of thought on the subject of what to do next. There is a strong contingent that advocates reinforcing the one (or two) bad welds in a particular manner using fasteners--there is a link to a thread on this in the subframe sticky at the top of the forum page. There is another school that believes that much of the problem is due to a bad welder at the plant, and that the one or two bad welds that show up may be all that you experience. I don't see any reason not to try the fastener route, and keep an eye on the remaining welds and the mount. There is a lot of information about the various fixes and costs linked in the subframe sticky, and also set out in this thread. Haggle with the seller based upon the bad weld and the potential cost of repair--he is bound to know about the issue. The picture shows a very early stage problem that might not even spread, but it is best to be fully informed. These cars are so much fun, and so great in every other detail (except the seat bushings), go in with your eyes open, but go in.

  15. #915
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    Thanks for the quick reply, yeah that were the only two that looked suspicious.
    I'm trying to figure all this out rather quickly. I'd love to take the plunge but can't afford any big repairs. The seller wasn't using it much and I figure mostly Sunday drives in the summer the last few years. They were completely unaware of this issue. So, makes it difficult to negotiate it off the price.
    I'll have to do some more research.
    Last edited by Fudged; 04-21-2013 at 05:40 PM.

  16. #916
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    1999 Z3 2.5L 5sp
    I would suggest that you need more information to make an informed decision, ie, the welds in the pic you posted, are the forward row of welds - and yes, there is one weld gone there. There is another row about 5" toward the rear of the car from that row. You'll need to remove the black plastic tool tray to see the row. If all you have is that one weld in the forward row - then, that's not perfect, but it's only one weld and one more to the left that might be on its way out. If the rearward row (the one hidden under the tool tray) is perfect, ie, no broken welds - then the car is probably viable, and as Bindley indicated: keep an eye on the rest and go from there. If all you have is that one blown one, I'd bolt it just so that ones on either side aren't forced to carry extra load. But, if you find more blown welds in the other row... then the seller better be willing to give you a significant discount - the full repair is $2000-3000 - or walk away [at least that's my two cents worth]. Good luck.

  17. #917
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    Thanks for the input, I should have removed the tool tray... The sellers were unaware and thought I was crazy. Or just beating them up to get a lower price. It is about 90 min. away, so not easy to drop by for another look.
    I'll make some calls tomorrow morning and figure out my options. There is a local shop (not dealer) that is highly recommended by some other owners.
    There is also an air bag light but seller said battery was just replaced before winter storage. So that has to be worked out also.

  18. #918
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    1998 M Roadster
    Battery replacement wouldn't throw an air bag code--get a PPI done and have it thoroughly checked out.

  19. #919
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    OK, calls going to be made tomorrow morning.
    Thanks

  20. #920
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    Quote Originally Posted by Fudged View Post
    Thanks for the input, I should have removed the tool tray... The sellers were unaware and thought I was crazy. Or just beating them up to get a lower price. It is about 90 min. away, so not easy to drop by for another look.
    I'll make some calls tomorrow morning and figure out my options. There is a local shop (not dealer) that is highly recommended by some other owners.
    There is also an air bag light but seller said battery was just replaced before winter storage. So that has to be worked out also.
    A couple thoughts: a) how about pointing the owner at this thread and let them read up - that way they might not feel like you're trying to screw them w/re price? b) instead of you spending 3 hrs driving back and forth, have them pull the tool tray, take some pics and send them to you - if they want to sell the Z, let them do a little work (very little)? and c) where are you in Canada? Maybe you have other choices?
    ps. the airbag light is probably because of dirty connections under the passenger seat - most Z's live with the airbag light on on the dash... but is a pretty easy fix (generally). Good luck.

  21. #921
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    I'm in Nova Scotia. I'm in no rush to buy. And can keep looking. This car looked otherwise in decent shape, no body or paint work, reasonable mileage, and interior was good (except seat rocking). I printed the buying thread and worked through everything.
    Hey, the more I look, the more I learn.

  22. #922
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    Apr 2011
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    Redding Calif
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    1999 Z3 2.5L 5sp
    Quote Originally Posted by Fudged View Post
    I'm in Nova Scotia. I'm in no rush to buy. And can keep looking. This car looked otherwise in decent shape, no body or paint work, reasonable mileage, and interior was good (except seat rocking). I printed the buying thread and worked through everything.
    Hey, the more I look, the more I learn.
    Yes, you might have fewer choices out there (but beautiful country).. might have to do like a lot of us and fly somewhere, take a train somewhere, and drive the Z home - suspect you'll have better choices in the Montreal/Ottawa/Toronto triangle area... or make a choice, assuming the one you've looked at doesn't have any further blown welds, just go with it. What is it? A 1.9, 2.3, 2.8, 3.0? How many miles? Auto? 5sp?

    - - - Updated - - -

    BTW: Autotrader currently has 588 Z3s listed - clearly 95% are in The States... but there are some Canadian ones listed. Question: is it worth the bother to try to bring a State-side Z into Canada, or not worth it?. If it is worth the effort, there are quite a few listed in the New England area. Don't know what you're looking for: early model - '96 thru '00 or later, '01 or '02; 4 cyl? small 6 cyl? larger 6 cyl? ///M? Auto trans, 5sp, colors?

  23. #923
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    Yes, fewer choices. This one is a 2.8 with 85 000 km. 5 speed.
    I looked at an auto 2.8 a few weeks ago but waited too long and it sold. I was debating the auto, I wanted a std. It sold.
    As for what I want... I'm not a big HP guy. I'm quite content to cruise along. I haven't driven the 1.9 yet so unsure if I'd like it. I don't mind turning a wrench either, just don't like throwing money down a hole. This will be purely a toy for me, so I'd like to be able to drive it while I fix it.
    Did I read here that this subframe issue is less likely in the automatic?

  24. #924
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    1999 Z3 2.5L 5sp
    Quote Originally Posted by Fudged View Post
    Yes, fewer choices. This one is a 2.8 with 85 000 km. 5 speed.
    I looked at an auto 2.8 a few weeks ago but waited too long and it sold. I was debating the auto, I wanted a std. It sold.
    As for what I want... I'm not a big HP guy. I'm quite content to cruise along. I haven't driven the 1.9 yet so unsure if I'd like it. I don't mind turning a wrench either, just don't like throwing money down a hole. This will be purely a toy for me, so I'd like to be able to drive it while I fix it.
    Did I read here that this subframe issue is less likely in the automatic?
    Less likely, yes, but not unlikely - know of a 3.0 auto with a half dozen popped welds, much to the distain of the owner... so it sounds like you have some choices locally. Is bringing something in from the state possible, or too much hassle. BTW - it seems that a well kept Z is at least a 200k mi car, maybe a 300k mi car... so, you might be able to pick up what the seller thinks is a high mileage car for a song and refurb it... we bought our's at 132k mi, now with 160k and looking toward 200k and then 300k.. have spend the last two years reburf'ing about everything - which has been fun. Given the success, am looking to buy another one for the oldest daughter, and another for the wife. Good cars, fun cars :-)

  25. #925
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    I haven't looked into importing something from states myself yet. But last car I looked at was a us car. And there is a company here that deals in imported cars. Obviously there is some taxes and inspection fees when car crosses the boarder so that eats up the cost savings. Plus, I think I'd find it hard to buy it on pictures alone ( it would have to be a really good deal). Maybe that's just me, but I've looked at a few, that the pictures didn't represent the condition of the car.

    BTW. 85000 km is about 53000 miles... So fairly low milage yet.
    Last edited by Fudged; 04-21-2013 at 09:11 PM.

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