540iT wagon: feel oscillation from rear suspension on bumps

[todor]

Hi everyone,
I'm noticing a vibration/oscillation in the rear axle when I go over bumps on the road, regardless of speed (happens during slow city driving as well as at highway speeds). Right after the bump I feel a vibration for, say, a third of a second.
My understanding is that blown shocks or shock mounts would result in this... am I correct? From what I hear, shock mounts on E39s don't really go bad (unlike those on E36s)... My car has 109k miles and it's a 540iT wagon with the self-leveling rear suspension.

I used to have a constant shimmy/vibration around 50mph but I just replaced the rear ball joints and that vibration is gone! But, i still have the oscillation when going over bumps. I think it's even more pronounced now, after I replaced the ball joints. I suppose it's possible that I damaged the shocks or shock mounts during the install of the new ball joints because I kept pulling down on the shocks with a lot of force to get the other components to line up...

What do you guys think?

And also, how do you get to the upper shock mounts on a wagon with self-leveling suspension? I've read a lot of info here but it's all about sedans that have a spring-over-shock rear suspension... my touring doesn't have coil springs and the shocks are just by themselves and kind of go inward diagonally toward the car instead of being positioned vertically like they are on the sedan.

[todor]

surely, somebody must know what the problem is here.... help please

[dinan e39]

could be shock mounts, maybe flex discs. take it to your indy and have it diagnosed.

[todor]

could be shock mounts, maybe flex discs. take it to your indy and have it diagnosed.

what are the flex discs? the only flex disk I know of is on the drive shaft...

i could diagnose the shock mounts by myself if i could see them... any of you guys know how to get to them on a wagon with self-leveling suspension?

so, in general, the malfunction of the damper assembly would lead to such oscillation? if we can narrow it down to the damper assembly (i.e. either shock or shock mount), then i'll know what to do. but is it likely to be something else? the sway bar links looked fine, as did all the other bushings around there that i visually inspected. Of course, a visual inspection is not very thorough - my ball joints looked fine too on the outside, but turned out to be very worn.

[rocketwagon]

Do a search for "rear axle carrier bushings" here and at Roadfly (and bimmerfest, I guess) and see if what's described there matches up with what you are feeling. I have a similar thing going on with my 528, but I'd describe it more as "floatiness" than oscillation. I'm choosing not to do anything about mine for now...

[todor]

Do a search for "rear axle carrier bushings" here and at Roadfly (and bimmerfest, I guess) and see if what's described there matches up with what you are feeling. I have a similar thing going on with my 528, but I'd describe it more as "floatiness" than oscillation. I'm choosing not to do anything about mine for now...

Excellent info! Thanks! I found the following thread that exactly describes my problem (which the British call "tremble"... I call it "oscillation") here:
http://www.bmwland.co.uk/talker/viewtopic.php?t=15799

Apparently the fix is, as you said, replacing the rear axle carrier bushings. The way I understand it, those are also known as subframe bushings. #2 in this picture:


So then the next question is how do you do it? The bushings cost $75 each... and I'd need 4 of them, so it's gonna get expensive if I have to pay for labor too... I couldn't find any DIYs online...

[rocketwagon]

Excellent info! Thanks! I found the following thread that exactly describes my problem (which the British call "tremble"... I call it "oscillation") here:
http://www.bmwland.co.uk/talker/viewtopic.php?t=15799

Apparently the fix is, as you said, replacing the rear axle carrier bushings. The way I understand it, those are also known as subframe bushings. #2 in this picture:


So then the next question is how do you do it? The bushings cost $75 each... and I'd need 4 of them, so it's gonna get expensive if I have to pay for labor too... I couldn't find any DIYs online...

I wish I had an answer for that question. The reason I have decided to "live with" mine for the time being is that the DIY looks like a *nightmare* even if I had access to a lift, which I don't. There's a guy on this forum who I bought some wheels from, BIMMERKILLA, who did the rear subframe bushings in his 540 sedan and said it was a tough job...and he's a mechanic at a Nissan dealership. So I'm guessing if it's tough for a pro to do the sedan, DIY on a touring is going to be a bitch. You might want to send him a PM or search for the thread.

In any case, let me know what you end up doing!

Good luck.

[dbruce]

I have an 00 iT with 70k and have the feeling in the back. It's not super annoying yet.....but I could tell after driving the car for a while something is worn and would need replacement.

I'd like to know the cost for this. The parts look cheap....but the labor looks like a nightmare. In addition, having to do it all over again in 60k or so isn't something I'm thrilled with either so maybe there are some better parts out there somewhere.

[dbruce]

Just looked up the part and there are 4 of them:

02 RUBBER MOUNTING 4 33311094036 $66.40

Labor is around 3 hours to install and a special tool is required to get the damn things off. Should be 540+tax....but of course with dealer markup and book time........700+ is probably the cost. On other thing, as it gets warmer, the problem gets worse.

[dbruce]

After doing a bit of research, the bushing can be found online for as little as $50...and I didn't exactly spend all day finding cheaper pricing.

Does anyone know of a method of doing the service without the "special" BMW tool?

Thanx in advance. This will probably have to go on the UK board since the touring are so rare here.

[todor]

man, i got a quote for $1100 for this job... (parts + labor)
the cheapest bushings i could find online cost $75 for the 540 wagon... (Lemfoerder brand, which is very good quality). they're probably a bit cheaper for the 528 as you pointed out.

i really don't wanna drop a grand on this. i'll sign up for the UK board and ask around there since as you mentioned, they have a lot more wagons there.

[dbruce]

I think the rear is the same for the 540 sport or standard:

Try http://www.mileoneparts.com/ and see if you can find a better price. They had the bushings for 50 and are a forum sponsor since they are affiliated with one of the dealers. On the UK board, several people had local indy's do the work. It can be done without the tool....it just makes it harder.

Haven't seen anyone on the board over there that has tried it themselves yet. I have a guy that can do it......but I want to make sure it's not going to be a major problem that will require a trip to the dealer eventually.

[cpatstone]

I was quoted $1500 or so. btw, my preferred term is "jiggly". whatever, it's annoying.

step 1 for me is to install new rear shocks. on the 528it, it's an easy job. Did you figure out how to get at the tops? I'd be surprised if yours were different.

I recall seeing a homemade tool that pulls out the bushing, without much disassembly. The official way is to pull the whole carrier assembly off... major surgery. Anyway, the e34 wagon guy who built the tool said that it probably wouldn't work for the e39 because it's a bigger bushing, or something. So, after replacing my shocks all around and the complete linkage set up front, I'll get to work on building that bushing puller.


An interesting experiment would be to sandwich some 1/4" neoprene sheet above and below the bushing, to tighten things up. Loosen the bolt, lower the carrier a little, slide it in. Wouldn't help much with radial movement, but axial should be a lot stiffer. Sort-of defeating the bushing, but, I'd take that over the jiggly-wiggly-oscillation.

BTW, when I pull off either shock, the first 1/4" or so doesn't offer much resistance. Bigger bumps are fine, small bumps do the same jiggles you describe.

Pic of the triangular cover removed, showing the top of the shock:


General view of the springed-variety of a Touring rear end:

[todor]

I think the rear is the same for the 540 sport or standard:

Try http://www.mileoneparts.com/ and see if you can find a better price. They had the bushings for 50 and are a forum sponsor since they are affiliated with one of the dealers. On the UK board, several people had local indy's do the work. It can be done without the tool....it just makes it harder.

Haven't seen anyone on the board over there that has tried it themselves yet. I have a guy that can do it......but I want to make sure it's not going to be a major problem that will require a trip to the dealer eventually.

thanks for the link, it seems like the one for the 540iT is $50.96, so the total plus shipping is around $225 for 4 of them. Beats the $300 that I was getting at autodoctorparts.com... except I don't know what brand those guys at mileone are selling. but anyway, the price difference is significant.

well, just last weekend I replaced my rear ball joints without the special tool (just using a generic bushing puller I borrowed from AutoZone for free), so if i know what the procedure is with the factory tool, maybe i can come up with a custom tool...

Does anyone know what the procedure is, even with the factory special tool? I might ask on the british board since those guys seemed to have access to the EKT or TIS software (or something of that sort) that dealers use for instructions.

[dbruce]

cpatstone

If you are talking about replacing the rear airbags.....from the British boards, you will notice no difference in anything. The most you'll get is a lower chance of losing an airbag in the future.

As for the brand from Milestone, one of the options was OEM at 50. Haven't a clue about the other options.....but I'd contact them for some clarification. This will happen every 60K.....so we need a solution that won't empty out wallets every 4 years.

Someone must know how to pull these things without getting raped by the dealer. There bushings and I have no intention of bending over if I can find another option.

[cpatstone]

If you are talking about replacing the rear airbags.....from the British boards, you will notice no difference in anything. The most you'll get is a lower chance of losing an airbag in the future.

I had wondered about the performance difference, but no, I have springs and no delusions of retrofitting airbags. My daydream is to build and use an extractor tool, and then just have the thing circulate around the E39 wagon DIY community. Unless someone's already done that?

[todor]

I would be willing to try to make a tool and then post instructions on how to make it... if only I knew what the procedure for the actual removal/installation was..

[cpatstone]

Hmm... I was thinking about defeating the bushings with Neoprene... apparently it's also done with Delrin (E34 application):

http://www.racingking.net/Canada/scr...?idProduct=693

or, if the bushing isn't shredded, fill the voids with rubbery glue:
http://forums.bimmerforums.com/forum...d.php?t=668407

[todor]

hmm that's interesting... the idea of filling up the voids with urethane. might be worth trying since the old bushings are trashed anyway, so if we mess them up even more, it's not a big deal

[dbruce]

Filling the void looks like a decent temporary fix. Getting a tool and a method of fixing this without having to go to the dealer is top of my list.

Where can we find a picture or something of the wonderful $600 tool that makes removing these things easy? There has to be a pic or something out there. Better then likely, it's just a tool to screw over the DIY people.....which BMW isn't fond of, as I found out today when trying to get an Alldata account for the 5'er.

I just looked around a bit and I think I found what the tool is. For the E39 touring, the bushings are much larger.....so the tool is larger and specialized....but should be similar to the master kit shown:

http://pelicanparts.com/catalog/shop...TOOLS1_pg2.htm

Check page 30 of the following......that be it:

http://www.klanngedore.com/pdf/chapter4.pdf

[todor]

I found another one at baumtools.com that looks pretty much exactly like the one from pelican parts. but the problem is that nobody has one for the e39, let alone the e39 touring...

[todor]

And another one on zdmak.com: http://www.zdmak.com/wbstore/main.as...CTMP=1&LowCt=0

[todor]

The actual bushing looks like this:

[dbruce]

The Klann one is for the touring. The issue is the size, it's huge on the E39 and rarity of the touring in the US doesn't help.

In any case, the price is crazy high I'm sure no matter who supplies the thing.

[todor]

haha, i didn't realize you started a new thread on the UK forum and I posted a message to the thread that I referenced earlier (the 7-page one that describes the problem)... well anyway, let's hope we get some info in response to one of our posts there.