*DIY E34 525iT M50 Auto to S52, 5-speed & 3.64 LSD Thread....

[TouringDan]

And so it begins... Well, actually, it will as soon as my chip from Turner gets here.

Anyway - this is not a project for the faint of heart. Any one of the three is not too big of a deal, but to do the engine conversion, trans conversion, and rear-end swapperoo all at once is a rather large task. I have blocked about a week of vacation days to get the job done, and I suspect that it'll take every damn minute of that week to do it. And I've got 20 years of engine building experience and an arsenal of air-tools on my side...

To start - here is the engine. It's a '98 S52 out of an 80k mile M3 that found itself wheels-up. (Thus, the oil all over everything...) Its OBD2, which is why you don't see any of the intake stuff on there - I've taken it all off. To convert the car over to an OBD1 system, you need to use the old intake manifold (with the M3 injectors), computer, and other sensor bits and pieces... Also - buy the engine temperature splitter from Turner. It's $40. The S52 uses one sender to send the signal out to the computer, the M50 uses two. You can either drill and tap the boss on the block and add another sender (ick...) or spend the $40 and get the splitter. Drilling and tapping is the last option, IMHO, and should only be done by a machine shop.



You will also need to use the pickup on the front of the engine for the computer. The M3 computer / S52 uses a trigger on the back of the block. The good news is that all of the existing stuff from the M50 will bolt right on. You also need to swap out the oil-pan and while you're in there, swap out the pickup tube. It either bolts on or is tacked on - I'll snap a pic when I am in there.

I went ahead and ordered a slew of new gaskets, bearings and seals from Autohaus Arizona. It's tricky because some of the stuff is specific to the S52, while other items will work on both.

Sidenote - The S52 and the M50 are identical blocks and heads. BMW got the increase in displacement and power via a stroke change, cams, and other bits. Matter of fact, even stamped on the side of the head is "2.5" for the M50 2.5 litre, and the block casting numbers are also in the M50 range. I had to do some judicious research to ensure that this engine was in-fact an S52. (Thanks to Nalley BMW in Decatur for the assist in the detective work...)

Now, the transmission.

I *thought* that once I scored the pedals and the driveshaft off of eBay, I was down to the nickel-and-dime stuff... Well, I was wrong. Expect to spend about as much on that stuff as you did on the trans. And no, you can't use the auto driveshaft. They're different.

All these little baggies:

That's over $200 of stuff from the dealership. Nuts, bolts, hoses, gaskets, bearings, mounts, washers, switches and seals. All essential for the job and none should be re-used unless you are very familiar with the source of the used parts. A lot of the bolts on the driveline are 'torque-to-yield'. This means that they should only be used ONCE. This doesn't include the rare-as-hen's-teeth manual transmission crossmember. You can get one from any E34 manual, but the yards know that BMW has them on a semi-permanent hold at the factory. Even though the dealer wants $35, they're going to get you for at least $50.

You can save on the pressure plate and clutch stuff - but I am an addict, and I have a spending problem and a high-credit limit.

UUC 8-lb aluminum flywheel.

I also got the BMW M5 pressure plate, and a Sachs clutch/throwout bearing. One critical item of note here - get a new PILOT BEARING. They're like $25 and a separate item from a throwout bearing. If you don't get one and install it now, while the trans is out, you'll be doing it later. I promise. Also - get a new Guibo. Even if the old one looks fine.... I'd also suggest a new pivot ball for the shift lever, and a retaining spring. El-cheapo to buy and put in while the trans is on the floor.

More updates to come - I am off on assignment for the next 5 working days, so it looks like Saturday the 21st is when I will be starting the project - barring anything unexpected....

[X Mon]

Drool....

Just one note: You can use any cross member from a M50 5spd AFTER '91. The early 5spds that were in the M20 cars are Getrag 260/5's and they use a different cross member.

[StealthBimmer]

oooooooooooooooooooooooo

should be fun

[Itsnotme1988]

Why use the 5-speed over the 6?

Can't wait for it to be done! I've been considering this myself (after the LS1/T56 is in the B2000 )

[atl530i]

Your in Tucker right?

[TouringDan]

Why use the 5-speed over the 6?

Can't wait for it to be done! I've been considering this myself (after the LS1/T56 is in the B2000 )

The 6-speed is slightly longer than the 5 speed, meaning that although possible (and tempting), a custom driveshaft would have to be made. (Edit - no it isn't...) Seeing as how I scored the OEM 5-speed shaft for $50, I didn't want to hassle with it. Now, the 6 speed will be going in once this 5 speed dies and once I strap the turbo on the engine, who knows how long that'll take...

Atl530 - I am in Tucker, right off of Lavista. I've been chewing on hosting a BMW love-fest for us Atl. folks...

[Roderic E34T]

A custom drive-shaft?

There have been 6-speed M5's. Doesn't that drive-shaft fit?

[TouringDan]

The M5 transmission is a different length than that of the M3 (E36). Plus, even if I am mistaken on the interchangeablility of the transmissions, the cost of a M5 driveshaft is probably equal, or greater than getting an OEM shaft shortened.

[HE53]

sweet.

[Roderic E34T]

The M5 transmission is a different length than that of the M3 (E36). Plus, even if I am mistaken on the interchangeablility of the transmissions, the cost of a M5 driveshaft is probably equal, or greater than getting an OEM shaft shortened.

Aah okay. Sorry. You are installing an E36 M3 engine. MY (BIG) mistake!

Friend of mine is putting an S38 in an E30, so that's why I thought about it.

[Craig S]

Is that an M3 tranny? If so, a 3.64 is going to make it rev pretty high on the freeway (since there is no overdrive). Seems like a car like this would be a cruiser, and you'd want to make it a little more enjoyable on the freeway.

Other than that, great project. I always thought an S50/52 swap would be a good option.

[X Mon]

The typical ZF boxes used in 5spd conversions on the Tourings are a 1:1 5th gear. I was planning on running a 3.23 with a 255/40-17 rear tyre. That ends up being:
Road Speed*Distance (1 mile)*Differential Ratio*Transmission Gear Ratio/Tyre Circumference
75MPH*{1hr/60min}*(5280ft/mile)/([(255mm*2*.40/{25.4mm/in})+17in]*3.14159/{12in/ft})*3.23:1*1:1

Which ends up being 3253RPM

This compares to the stock setup of the slush box, .72:1 Overdrive gear, 4.10 differential gear and the "stock" tyre size of 225/60-15
75MPH*{1hr/60min}*(5280ft/mile)/([(225mm*2*.60/{25.4mm/in})+15in]*3.14159/{12in/ft})*4.10:1*0.72:1

Or 2904 RPM which ends up being a change of +12%

Right now I'm running running the 255/40 with the autobox and stock rear end, so I'm seeing 2973 RPM, and thus realistically the change will only end up being around 9.5%

A 3.64 with a direct drive (1:1) 5th gear ends up putting you at 3666.

[Antrieb]

Good luck with the project

[TouringDan]

Is that an M3 tranny? If so, a 3.64 is going to make it rev pretty high on the freeway (since there is no overdrive).

Other than that, great project. I always thought an S50/52 swap would be a good option.

The trans is out of an E34 525i... As for highway driving, I am going to give the 3.64 a shot and see how it all works out. If I don't like it, I'll change it out again. My original goal was to get an S38B36, but they're a little pricey. I got the S52 for a complete steal.

[Craig S]

That will probably be fine. A 3.64 with an M3 tranny might not be.

[Whackamac]

With the performance I am getting out of my 525i, I am seriously thinking a "S" motor was put in when the prev owner changed engines...

Is it possible to put a M50 valve cover on an S50 or S52? I would assume that would be the case as they only did a longblock and this thing has a different chip... And my block looks just like that one other than the VC

Anyway... Nice mod! That engine is almost as clean as mine! I dont think mine has a spot of oil or grease anywhere... I could lick it!

[LJSE34]

This is going to be an interesting thread

[blackparis]

*Subscribed*

[brosher]

*Subscribed*

+1, can't wait to see the progress. Take lots of pics!

[TouringDan]

Unlike everyone else I've seen, I decided to yank the whole pedal cluster and change it out to the manual. This wasn't because I am uber, it's merely because I lack a welder... That being said, here is the progress. Step 1 is to drop the steering column. This is a hell of a lot easier said than done - and I've heard that changing the pedal cluster as a whole, is harder than swapping the engine. After today, I believe it.

Edit: Now that the whole job is done, changing the pedals was a cakewalk compared to everything else....

Pull off all the bolsters and covers, and pay attention to the wiring harness from the wheel.

This harness is all of the wiring from the wheel. It's directly to the left of the column.

There is one other wire, and that goes to the computer above the rat's-nest of wiring that is above your left knee:

This is the airbag connector. It's quite hidden and runs along the top of all the rest of the wires. It will terminate at the computer and it has a yellow connector. Either disconnect your battery, or make damn sure that you don't turn the ignition on without this being plugged back in. Otherwise, the SRS light will be on and only a trip to the dealer can reset it.

Ok - so pull off all the covers, and label all the wires you are disconnecting. Why? Well -

It's easy to get lost in here. That's why.

A sharpie works great. Even on the black connectors:]


Don't forget the brake light plug. That's down at the pedals... (Sorry about the focus... This pic is useful for the colors of the wires to the switch...)


Now, I've read the stories of the "unmoveable bolt" and here it is:

and it's every bit as bad to get out as expected. This puppy is almost directly above where the 2 sections of the steering shaft meet. Matter of fact, you can see the union in this picture. There is no way to remove it in-tact that I am aware of... You can either torch it off (not a good idea), cut a groove in it with a cutting disc in the hopes that you can get a flathead screwdriver to bite, (more sparks - not a good idea...) or use a dremel to grind the head into oblivion. A dremel with a carbide bit made rather fast work of the bolt head. No sparks, but lots and lots of miniscule metal shavings. I wore safety glasses, but I'd suggest a full-face shield and some long sleeves. I feel like I've been rolling in fiberglass.... Once that was out, there are 2 bolts near the steering wheel to remove (above the column - straddling it on either side), then there are 2 more bolts that control the pivot-point for the telescoping column. You can't miss them. Remove them. Disconnect the cable that runs from the steering column to the dark depths of the dash. It starts at the ignition switch and is a simple unscrewing of the nut. Pull the cable free and tuck it away - then the column itself is free.

Edit: The cable you are pulling free is the lock for the key-release that goes to the auto-trans gear selector. Save this cable! You need to re-install it once the auto-selector has been removed or you won't be able to get your key out.

What I decided to do, was disconnect the column from the flex-joint and leave the lower column in place. 4 nuts and done. NOTE: There's a little friggin spring that came shooting out of here when I took the halves apart. It looks like an "L" with the coil of the spring being in the crook of the "L". When re-assembling, on either end of this spring is an eye, and you push one stud on the lower column through one eye, and a stud from the upper column in the other. Simple stuff.


Now to the pedals themselves... Remove the clip that holds the pin through the brake pedal. Pop it up with a screwdriver and slide it off. Takes mere seconds...


There are 4 nuts on the firewall, one bolt, and then 2 more nuts above where your knees would be in the driver's seat. Remove them. With some careful manueving of the pedal cluster over the steering shaft, you can remove it from the car. The throttle cable is held on with a rubber grommet - just push it through the pedal-lever. The throttle pedal needs a little manipulation to get it to let go of the lever. Allign the lever with the notch in the pedal as shown here:

Thats the top of the throttle pedal.

Get those done, and viola


Here are the clusters side by side. Auto on the right, manual on the left. The round hole in the center of the bracket is for the brake rod.


Now - pick up the manual cluster, and on the way to the car, accidentally drop it from about 3 feet. Then you'll break the clutch return spring and it's a special order part from BMW.

It ain't supposed to be in two pieces...

Dammit...

Well - time for some refreshments:


Once I am done with my pizza and brew, I'll start removing the hood, and begin the process of removing the engine and trans. Just a tip that I've learned from the dozens of engines that I've done - when you remove a bolt or a nut to take out a part, if at all possible - put those nuts and bolts back on the studs. This will keep you from losing them and/or wondering where they go when you re-assemble.

More to come

[HE53]

I can't wait to take a week off work to drink weat beer, eat pizza, and do an engine swap. Your a lucky duck.

[kalevera]

Unlike everyone else I've seen, I decided to yank the whole pedal cluster and change it out to the manual. This wasn't because I am uber, it's merely because I lack a welder... That being said, here is the progress. Step 1 is to drop the steering column. This is a hell of a lot easier said than done - and I've heard that changing the pedal cluster as a whole, is harder than swapping the engine. After today, I believe it.

man, I've been saying this for years --

http://www.bimmer.info/forum/showpos...2&postcount=37

Now, I've read the stories of the "unmoveable bolt" and here it is:

and it's every bit as bad to get out as expected. This puppy is almost directly above where the 2 sections of the steering shaft meet. Matter of fact, you can see the union in this picture. There is no way to remove it in-tact that I am aware of... You can either torch it off (not a good idea), cut a groove in it with a cutting disc in the hopes that you can get a flathead screwdriver to bite, (more sparks - not a good idea...) or use a dremel to grind the head into oblivion. A dremel with a carbide bit made rather fast work of the bolt head. No sparks, but lots and lots of miniscule metal shavings. I wore safety glasses, but I'd suggest a full-face shield and some long sleeves. I feel like I've been rolling in fiberglass.... Once that was out, there are 2 bolts near the steering wheel to remove (above the column - straddling it on either side), then there are 2 more bolts that control the pivot-point for the telescoping column. You can't miss them. Remove them. Disconnect the cable that runs from the steering column to the dark depths of the dash. It starts at the ignition switch and is a simple unscrewing of the nut. Pull the cable free and tuck it away - then the column itself is free.

If you have an air chisel, it comes out in a few seconds

Now - pick up the manual cluster, and drop it from about 3 feet. Then you'll break the clutch return spring and it's a special order part from BMW.

It ain't supposed to be in two pieces...

Dammit...

Good news is that when that pin breaks in the car, you can still manipulate the clutch

[attack eagle]

Subscribed. I'll never do it... but interested nonetheless.


EDIT 11/11/07: OH HOW WRONG I WAS!!!

[TouringDan]

Taking a hot-dog and beer break before I go out there and continue... For the most part, I am going to leave the details of removing the engine and trans to the Bentley's manual and I'll just cover some of the more interesting/perplexing things that are not mentioned in there.

Ok - so now to remove the hood. Step 1 - remove the hood-insulation. Look for these and unscrew them.

Just be warned - they have a tendency to come shooting out of there, so be careful. There are about 23,211 of them on the insulation so make sure you get them all off.

Bag and tag - don't lose them


Now to disconnect the nozzle heaters and the fluid lines.


There's one bolt on either side of the front hinge - don't undo it yet!


Make sure you release the side hinges and the pistons first! I know, sounds basic, but, um.... I know of what I speak...

Ok - so remove the hood, and set it aside somewhere where it is out of the way and safe.


There are tons of wires in here. Tip: label everything. It doesn't have to make sense to anyone but you - but make sure you do it. It'll make re-assembly tons easier.


Have that fuel-smell in the morning? Change the hoses at either end of the fuel rail - the feed and return.


The other side:


Tuck the fuel rail somewhere safe and out of the way.


This pipe I have my hand on is on the S52. It is one of the main differences between the S52 and the M50. Notice how it is simply pressed-in to the engine. It will not be needed for the conversion. Twist a lot and wiggle it out.


Now here is the same part on the M50 - notice how it is a nipple for a hose instead of a hole for a pipe.

Turner Motorsports sells a kit to convert it. The kit is $35 and well-worth it.

I love the engineers. They even make sure that you can't screw up the wiring on the starter by using different size fasteners....


Remember to label everything!


When you disconnect some of these connections, keep a keen eye out for these babies:
They are the internal seals for the connections and they fall out like engine-dandruff. Keep them around - you'll need them

Now - whizz off the bolts that join the exhaust pipes to the headers. They are 13mm, but don't expect them to fit a 13mm socket. The thousands of heat/cool cycles have probably converted them into some bastardasation of a bolt size - in between a 13mm and a 14mm. Just get a good old Craftsman socket and whack the hell out of it to get it to bite on the nuts. A good soaking of some penetrating oil helps. I was lucky - I got all 6 of mine off without breaking one stud.

Now remove the actual headers since they will be used on the S52. Don't be surprised if this happens:

Yes, that's the nut, and the stud - coming out as one. Great.......

Even better -

Every single one of these damn things came out as one....

Ok - beer is done. Time to go yank the engine and trans....

[HE53]

Waiting for pics.