E24 Euro Auto to Manual Transmission Swap DIY

[SixerFixer]

Inspired by Jeff's Wolfie thread, I have decided to do an ownership log of my 6er. She's going to be getting quite a bit of work done over the coming winter months, so I figured that instead of making individual threads as I progress, one big one to include everything would be for the best. Her name's Hanna, and she's a 10/87 635CSiA grey market car:



I've owned her since mid-2006, she's seen a grand total of 71,000km (~43,000 miles), and I keep her around to enjoy on nice, sunny days. The car is Alpinweiss (146) with an Anthrazit velour (0221) interior.

290 BMW LM-RAEDER 7JX15,225/55R15V
401 SLIDING/VENT ROOF, ELECTRIC
458 SEAT ADJUSTMENT, ELECTRIC. F DRIVER/PASS
494 SEAT HEATING F DRIVER/FRONT PASSENGER
498 HEADRESTS IN REAR, MECHANIC. ADJUSTABLE
500 HEADLIGHT WASHER SYS/INTENSIVE CLEANING
510 HEADLIGHT BEAM-THROW CONTR. F LOW BEAM

She also had the self-levelling rear suspension setup installed, but it appears that the PO swapped the rear struts out with a set of OEM springs and Bilstein struts. The headlight-level control system also failed and was swapped out (by me) with manual headlight aim adjusters. The front brakes have been updated to E32 components (calipers, carriers, pads, rotors), the rears with E34 components, and the brake lines have been replaced with stainless steel lines. The engine compartment's been thoroughly cleaned, and many discolored, faded, or rusted parts have either been replaced, refinished. I'd love to say that it's 100% rust-free, but a small bubble has formed on the passenger-side wheel arch, just under the side trim.

Anyways, I could talk on and on about what the car does or doesn't have but I'd much rather aim this thread towards my plans for the coming months. I love the car to death but what it's lacking (and what I want) are a manual gearbox, a limited slip differential, and some nicer seats (these comfort seats are anything but comfortable). I purchased an '84 635CSi parts car late last year which had a few of the things I wanted. The car was a horribly abused frankenstein project which never saw the light of day (thank god), but she ran and was mostly complete. I parted it down to a rolling shell, and stuffed everything it had into my garage and basement, and just this afternoon, the rest of the shell was taken to the scrap yard to get shredded:



I would have loved to save another 6er, but trust me when I say that this one was too far gone to save. I live in central Canada, and our winters take a toll on cars. Lots of salt is thrown about on the roads during the winter months to combat ice formation and allow for drivable roads, but the salt also causes a considerable amount of rust to form on any cars that drive on it. This car was no exception, so believe me when I say that it was beyond saving.

It did however allow me to loot it of quite literally everything. Since it was an early build car, it came with a Getrag 265 OD gearbox with removable bell housing, which was mated to a 3.46 limited slip differential. A friend of mine was parting out an E12 528i, from which I acquired a single-mass flywheel which has been resurfaced. Since my 6er is a late E24, it has the M30B35, which does not have any flywheel reference sensors, so I can get away with mating it up with the E12 flywheel. I also bought an E28 M5 clutch and pressure plate, which will be used in my conversion.




As I mentioned, the parts car also gave me a 3.46 LSD which I plan on re-sealing, painting, and tossing into Hanna. The differential is completely stripped of any paint due to rust formation, and I'd like to to be at least somewhat presentable before I put it into my car, and I have no idea where to start with disassembly and repainting, so any advice would be appreciated.


(the output shafts were removed before I took the photo)

Winter here in Winnipeg allows for oodles of free time to be spent on projects like this, and I intend on documenting my progress every step of the way. If anyone wants any pics of particular steps in my progress, feel free to ask, as I will be more than happy to provide.

-Emil

[Shipper]

Wow, wonderful car! Love the post!!

[BoldUlysses]

Awesome thread, Emil. Nice to (formally) meet Hanna. Mine is nameless thus far... But I'm sure she'll name herself soon enough.

I'll be following this thread with interest.

-Matt

[sixseries]

love the car and THE WHEELS

[YK91]

Car looks amazing, the wheels should look even better in silver. It will be a blast with that 5spd in there. Have fun on your project, my 6 is about to go through an entire suspension rebuild.

[Zack01GC]

Gorgeous.

[TopGear328i]

absolutely splendid car mate. I luv the e24s, I'd trade my e36 for one of those in a heart beat. Well done with the car and keep us updated on Hanna

[jbd5015]

Emil, great idea on starting a thread. it's also a great thing to have to look back on through every once in a while to see how the car has progressed.

you have one great looking car, something about original paint makes these cars look amazing. when you put that 5 spd in and that diff, coupled with sport seats itll change the car.

-Jeff

[Captain Bavaria]

I am in love with your rims.

[JRanmann]

I didn't know that you knew Hanna so well?

[SixerFixer]

Thanks for the kind words, guys!

First update! I started ripping the interior apart and pulled the automatic shift console out. I removed the entire centre console out and began examining the wiring for what has to be removed. My plan is to do this swap slowly and carefully, making sure not to cut any corners; I do have until next April, after all!



2 of my latest acquisitions are a Sachs M5/M6 clutch and pressure plate, and a period-correct amplifier for the car, made by Proton at some point during the late 80s/early 90s. I'm not sure if I'm going to bother using the amp to power the front speakers or just leave everything well enough alone, seeing as how I already have big enough plans for the winter months.



-Emil

[Bert Poliakoff]

Is that Hanna, as in hard hearted Hanna?/ or is yours soft hearted??

[SixerFixer]

She's a medium between the two :p

[SixerFixer]

I got some more work accomplished the other day; the entire transmission wiring harness has been removed! A great majority of the harness is stuffed under the dash, and it is quite bothersome to get at (I actually had to cut some sections to allow for easier removal), but I was able to remove a great deal of it in under an hour:



However, one part of the harness gave me quite a bit more trouble than the rest of it, and that bit travels down into the transmission tunnel, clips to the transmission, then is 'screwed' into the side of the ZF 4HP22 automatic gearbox.




It only gave me trouble because the connector is in an awkward place. I have larger hands, and couldn't quite get my fingers around the screw-in connector, so what I had to do was use a pair of needle-nose pliers to push at the side of the connector to try and turn it, using the transmission tunnel corner with the undercarriage as leverage. I finally did get it out, and after unclipping it from a spot on the transmission, I was able to pull it up and out.



I've been coordinating my swap with one that was done on an E28 528e a few years ago, and let me tell you that this harness is at LEAST 3 times the size of the harness in an ETA. For comparisons sake, here is a picture of a 528e's automatic transmission wiring harness:



Quite the difference, eh?

I traced everything up from the shift selector connector, and traced it up to a spot where it branches behind the gauge cluster. Traveling to the passenger-side of the vehicle, it connects to a connector off the harness going to the ECU, and to another box behind the heater controls which I'm yet to remove (I'd like to know what it does first).

Behind the cluster, it branches off to the range selector board that plugs into the back of the gauge cluster. That branch also has a pair of connectors that attach to a panel next to the steering column. Continuing with the main body of the harness (heading left), another small branch is found which travels to what I believe is the power distribution box, to a start relay, and 3 more connectors (one of which is green, and the other two are translucent). Another wire is here which gave me grief, but it ended up going to the kick-down switch behind the accelerator pedal. Finally, the main harness ends at the transmission control unit, which is connected with a large connector, similar to the one for the main ECU for the vehicle. I tried to draw a diagram here to better describe what I'm trying to say:



Lastly, I took a picture of the transmission control unit, so that anyone attempting the swap themselves will know what to look for:



In the end, I was left with a single black connector by the steering column, and a translucent connector by the power distribution box above the dead pedal, which I do not know what to do with. I also had to cut a single blue/yellow wire traveling to the range selector connector, which seemed to have sprouted from another harness. From my understanding, I was to cut this as close to the connector as possible, so it can be used for a ground. The ETM shows that this wire corresponds to Neutral on the range selector, so I would assume that without this being grounded, the car would not want to start.

Any further insight on the matter would be greatly appreciated! I'd love to know what I should be doing with those two now-disconnected connectors!

Cheers,
-Emil

[BoldUlysses]

Great work, Emil! That harness is a beast! I'm sure you had the "Well, there's no going back now" feeling when you cut the harness. I'm lusting after your uncracked dash, too. Mmm...

I'm sure CW will chime in about the electrical bits.

Have you considered cross-posting this on BigCoupe? It would make a fabulous tech article when you're all done and a great thread in the project area as it stands now.

Well done sir!
-Matt

[SixerFixer]

I was actually contemplating cross-posting this thread, but I decided that when everything's done, I'll just make a series of master threads documenting everything on bigcoupe (one for rebuilding/resealing the differential, one for the 5-speed conversion, etc etc), so they can go straight into the tech articles section for future reference.

And regarding the 'no going back feeling', you're exactly right! I tried pulling the part of the harness that goes behind the heater controls through, only to realize that it wasn't meant to be removed that way, so rather than removing the dash and all sorts of other tidbits, I figured that it would just be easier to cut the offending connector off.

[dm635]

I have done this swap on an E30. The electrical part appears much easier for it. There were 3 or 4 critical jumpers. I just followed every circuit in the ETM, Bentley and any other schematic I could get my hands on. Sounds like you're comfortable reading them as well. Can't give any advice at this point. You're going to have a different car.

[SixerFixer]

My most recent progress so far has been removing the catback portion of the exhaust and heatshield, finding and freeing up the cruise control clutch disable switch wiring, removing the steering column, and removing the automatic pedal box.

First I removed the exhaust. It appears that the previous owner either installed a catalytic converter (if there wasn't one previously), or replaced a failed one. Regardless, the piping appears to have been changed at some point in the recent past, allowing for the exhaust to easily be disconnected. The hangers unbolted, and the system was removed from the car. The bolts that affix the downpipe to the exhaust manifolds are seized, so I sprayed them down in PB blaster with the intention to attack them at a later time. The heat shield was easy to remove; it was only held in with 6 10mm nuts (I apologize for not really taking any photos of these steps)



Next up was removing the pedal box! I just knew that the steering column would get in the way eventually, so I decided that it would be easier to just remove it now and have all the extra space to work with. It was only held in with 5 13mm bolts, two of which had 13mm nuts attached to the other side, so a wrench was needed in addition to my ratchet (those ones are identified in red):



Now, with the steering column out of the way, doesn't this look far less intimidating?



Hm, maybe not. Lets get that pedal box out of the way! The brake pedal is attached to the master cylinder by a through bolt, which is clipped in on one side, and the other side is attached to a spring. It's a pesky little clip that needs to be lifted in order to allow for it to slide off. The through bolt is also attached to a spring which must be disconnected to allow for the bolt to slide out.





With the brake pedal disconnected, another spring must be disconnected from the accelerator pedal. Once this is done, you can get at the 4 13mm bolts holding the box in from the top, and 4 13mm nuts attaching the box to the firewall and master cylinder. The bolts are identified in green (I removed one before remembering to snap a pic so where it would have been visible is identified in its place), and the nuts are in blue:




Once those are undone, the pedal box can simply be pulled out. With no steering column in the way, there's nothing to interfere with its removal, so it just slides right out.




Much better!

The next thing I tackled was freeing up the connector that would attach to the cruise control disengage switch on the clutch pedal of the manual box. After following some wiring, I discovered that it was zip tied to some of the harness near the check control panel. It was plugged into another section of harness that simply grounded out the connection. Here's what it looks like:



In my last post, I mentioned two mystery connectors:



(in the second photo, it identified in red)

I'm fairly certain that the one in the second photo connects to the lone female terminal in the bit of the harness attached to the steering column, but the white connector in the first photo confuses me. I can't figure out where it goes for the life of me. Again, any suggestions would be appreciated. Perhaps someone is able to check their distribution panel to see where it goes? It's a blue/yellow wire.

Anyway, I'm likely going to try and remove that downpipe tonight, so expect another update soon.

-Emil

[BoldUlysses]

Your car has the cleanest underside I've ever seen. Actually, it's the cleanest all-around 6er I've ever seen. Most impressive.

I'm sure I'll have to replace my clutch MC eventually. I wonder if it would be worth it to remove the steering column like you have to be able to access the area more easily, when the time comes.

Keep up the good work!

-Matt

[danny2010]

absolutely splendid car mate. I luv the e24s, I'd trade my e36 for one of those in a heart beat. Well done with the car and keep us updated on Hanna

i could arrange this .

love those wheels. they look really amazing on Hannah

[SixerFixer]

Your car has the cleanest underside I've ever seen. Actually, it's the cleanest all-around 6er I've ever seen. Most impressive.

I'm sure I'll have to replace my clutch MC eventually. I wonder if it would be worth it to remove the steering column like you have to be able to access the area more easily, when the time comes.

Keep up the good work!

-Matt

It's quite easy and will save quite a bit of time in my opinion. Everything is just that much more accessible.

Thanks for the kind words guys!

-Emil

[nicobaires]

She's beautiful!! Looks just like mine!!

[FernandoBunster]

Great job you're doing Emil. Plan to do it to my 86. This might be helpful:
http://web.archive.org/web/200311151...m/kan/e28.html

[SixerFixer]

Thank you for the link, Fernando. It will come in most handy!

On a side note, a bit more progress has been made. I removed the downpipe, and will begin rebuilding the pedal box I have. The clutch pedal arm looks a worn and tired with rust forming, so I will be disassembling the pedal box, repainting the pedal bodies, replacing the pedal bushings, re-greasing all rotating assemblies and springs, and installing the nicely refurbished pedal box into the car. I ordered the following new parts for the pedal box:

35 41 1 113 728 - grommet x1
34 31 1 152 270 - pin x1
35 21 1 109 541 - bushing x4
35 21 1 150 346 - sleeve
35 31 1 154 734 - sleeve
35 11 1 150 370 - seal

-Emil

[JRanmann]

As I mentioned, the parts car also gave me a 3.46 LSD which I plan on re-sealing, painting, and tossing into Hanna. The differential is completely stripped of any paint due to rust formation, and I'd like to to be at least somewhat presentable before I put it into my car, and I have no idea where to start with disassembly and repainting, so any advice would be appreciated.

Here's what a 3.47 looks like cleaned up...



Given it's coat of road deposits I suggest that you consider swapping same for a refurbished unit...perhaps with Aardvark in San Diego who may have that very same unit. I know he has a 3.25 as we have discussed a swap recently and also this 4.27 listed on ebay. Give Dave (Aardvark) a call if you think it might be a reasonable option and at least he can guide your efforts to do this yourself.

http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWAX%3AIT

Also Serge here on ebay has the 3.47 LS (pictured) available for $350.00 or offer.

Item: 230392389048

http://cgi.ebay.com/ebaymotors/ws/eB...#ht_500wt_1182

Cheers!

Ran