Problem of a crooked engine/transmission not centered in the tunnel

[Chilezen]

I'm like 70% of the way through with an M52 swap, and I'm considering putting the M20 back in. Here's where I'm at:

Engine Mounts: I'm on AKG black poly mounts, and rubber E21 trans mounts. First off, the oil pan is EXTREMELY close to the subframe; I'm surprised the engine sits that low. But the main issue I'm facing is how the transmission isn't centered in the tunnel. I'm using a ZF, and I noticed this misalignment when I went to install the shift carrier. At its widest point, I can fit 2 fingers between the trans & tunnel on the passenger side, whereas I can fit 3 fingers on the driver's side. Sadly, this wasn't evident to my friend helping, who tried to install the shift carrier first, and he broke the ear when trying to put the bitch clip on. Even just mocking it up, the carrier & shift lever are definitely pinned on the passenger side opening.

Brake Booster: I've heard good things about the E83/X3 booster working. There has been confirmed fitment. However, even after shaving the fins off the M52 manifold, it still contacts at the booster's widest point towards the firewall. I took out the booster and shaved the metal off that area to help, and it still contacts. So I put a thick washer under the driver's side arm. That helped, it no longer contacts. I can get a piece of cardstock in there, that's about it.

Engine Arms: I have an aluminum M52 from a Z3. I did also have a regular E36 M52 at one point. Thus, I had 2 sets of engine arms from those two engines. The arms looked identical. But now I'm questioning if the z3 arms are different, and if I unknowingly used those arms, causing this misalignment. I can't find a source on this at the moment. I don't have the other set of arms anymore to test out.

I don't know whether the mounts are the culprit, or the arms, or something else in the process of installation. I don't know how to "twist" the engine so the trans is centered. Right now I'm frustrated that I had done as much prep as I could beforehand, making sure I had the right parts and information, because my window to perform the swap was limited, and I'm just about out of time. I wish I could just shove the trans to the center, but I can't. Thank you for the advice.

[twright]

If you want to try and twist the engine, try this: loosen up ALL of the engine and trans mount bolts. Then push the engine the direction you want. I'll bet there is enough slop in there to put the engine where you want..

[e30austin]

go buy genuine e28m5 rubber engine mounts. the AKG poly units are 100% unnecessary and have less than stellar fitment (in my opinion).

[2mAn]

I had zero issues with AKG and e21 mounts. Only thing I can suggest at this point is to double check where the mounts are slotted in the subframe. I broke one of my engine arms and it was replaced with OEM arms, I never specified that it was an aluminum block, and I don’t think they would’ve made special arms for one specific block.

Silly things happen, just go back and double check your work and like was suggested above, loosen the mounts and try to center the motor/ trans that way.

Swaps are always filled with stuff like this.

[Northern]

+1 to loosen everything and manhandle it by the output shaft on the trans.

Only other thing I can think of is motor mount orientation/whether they're supposed to mount in the stock holes or the slot for the pin.

Or just the offset in the ZF shift carrier? page 3 has a pic of how it isn't straight.

https://www.r3vlimited.com/board/forum/e30-technical-forums/24v-engine-swaps/m50-52-s50-52/36153-shift-carrier-question/page3

I think you can live with it if bushings are soft enough, or move the stud on the rear bushing bracket over to counter the offset at the back.
Maybe can use a G260 carrier, MK1 eyeball says length is close but not sure if it fits.

[Northern]

R3v won't let me edit, so here's a pic of what I mean by "move the stud on the rear bushing bracket over"

https://www.r3vlimited.com/board/forum/general-forums/members-rides/the-project-forum/309066-northern-s-sterlingsilber-m52-turbo-325is?p=6309835#post6309835

[Chilezen]

Loosening and wiggling was the first thing to do, to no avail. I have since enlarged all 5 holes in each arm, so I have more room to play. That, plus holding/pushing the tail of the trans, has gotten it close enough to center, so far. The rubber trans mounts definitely don't like this, as they're quite skewed, but oh well.

...I never specified that it was an aluminum block, and I don’t think they would’ve made special arms for one specific block.

Right, I agree, the block shouldn't be different; my question is if the Z3 has different arms or a different subframe compared to an E36. I doubt it but I have no idea.

here's a pic of what I mean by "move the stud on the rear bushing bracket over"

That's a good idea! And yeah, that photo of how the carrier sits is spot on with mine. Crazy. I swear I've been reading and reading on here, but haven't come across that. Anyway I can weld the tab slightly over. Thank you!


As of now, I had to drop the trans out because the tab that holds the carrier & bitch clip snapped off the trans. So I gotta weld that back on, and start all over aligning this shit.

[Northern]

The offset was very noticable with solid front/rear carrier bushings, but I guess the thought of the driveline being offset didn't cross my mind so I jumped straight to modifying the bracket lol.

I imagine there's less rigid bushings (old/stock?) that could be manhandled into place, so maybe some people just bolt it up and don't even notice.

[eternal24k]

I had the same issue, I loosened the bolt of the arms on the block, I didn't realize they were slotted, but that did the trick. AKG mounts with E83 booster and E21 trans mounts in cups (now running rogue with no issues).

Here's a post from my thread that shows the difference:

Well, I found why the Trans was not wanting to center, I loosened both mount arms and it centered, I did not realize the mounts had slotted holes for the bolts, so once it centered I was able to tighten everything up. You can see the difference on the trans mounts.

Before:


After:


It’s off center, but I think it will do…

Neutral:


5th Gear:


Reverse:

[Chilezen]

Ghad damn I had read your thread before, I saw you had this same problem! But I couldn't remember who! Thank you!

I don't have the aluminum cups to hold the mounts a little more upright. It looks like that makes a difference a bit.