Swapping my gearbox

Post Sat Jan 29, 2011 12:18 pm

I'm about to start changing the gearbox on my M52. How easy is it to get to the bolts with the engine in ?

Would it be easier quicker to pull the engine out ?

Post Sat Jan 29, 2011 5:15 pm

I changed the box & fly on my M50 in-situ a few months back, it was a right ball ache - you can just about get to the bolts with a fair few extensions together and the engine dropped down a few cm. This was on a 4-post ramp. We had one of us snaking their hand up to hold the socket home on each bolt and one about 6 feet back on the ratchet

Post Sat Jan 29, 2011 9:33 pm

Nightmare job!

Post Sun Jan 30, 2011 12:54 pm

Looks like i'll be living with a noisy box for this summer then

Post Mon Jan 31, 2011 12:54 am

Is this only problem with e36 gearboxes?

If I'm using the 318is gearbox I wouldn't expect this to be any harder than with a 318is. Someone educate me please.

Post Mon Jan 31, 2011 8:58 am

The M50 is a taller engine, so the top 2 bellhousing bolts are above the trans tunnel, effectively in front of the bulkhead, to get to these you need to drop the engine down around 4 inches regardless of what gearbox your using

Post Mon Jan 31, 2011 11:18 am

Hmmm, thanks for the info.
Hope my clutch holds!

How do you drop the engine? Front subframe or is it possible to loosen the mounts, undo the gearbox mount (and prop) and tip it back?

Post Mon Jan 31, 2011 12:01 pm

The subframe has to be dropped, you cant tip the engine back as its less than an inch away from the bulkhead as it is.
Anybody who has had to this job will agree that not fitting a new clutch while converting is madness

Post Mon Jan 31, 2011 12:03 pm

I've done a clutch on the E36 M50 and the top two bolts were a nightmare.

Needless to say one didn't go back in the other was for the starter.

I can only imagine it's a real ball ache on an E30. But not impossible.

Post Mon Jan 31, 2011 12:19 pm

Time to dig an inspection pit!

Post Tue Feb 01, 2011 4:45 pm

gudgeon wrote:Hmmm, thanks for the info.
Hope my clutch holds!

How do you drop the engine? Front subframe or is it possible to loosen the mounts, undo the gearbox mount (and prop) and tip it back?

As Dan said we took the 4 subframe bolts out and dropped the lot down, supporting it on a transmission jack. IIRC you could only drop it down so far before it started fouling things like the servo. I was doing a bit more work than just the gearbox cause I was changing flywheel. Meaning the starter had to come off too which was also a ball ache in it's self with everything in-situ. And a bit of welding on the slave cylinder (lol) But with two of us in a pukka garage on a 4-post ramp we started about 3pm and drove out getting on for midnight...

If you're doing it on your drive I'd consider just spending the weekend taking the whole engine & box in & out, its a lot of work still but it's easy work rather than mithering about.

Post Wed Feb 02, 2011 3:30 pm

If I were to do it on mine I would drop the subframe. As dan said, the m50 is so close to the bulkhead the engine cannot be tilted back enough.

Clutch change = a mission but welcome to the world of 24v's lol

Post Wed Feb 02, 2011 3:41 pm

Sounds like a big job, and I don't know about anyone else but I always feel a bit vulnerable under a car on stands. Without a pit or a proper lift it sounds lile removal is the best option.

You could disconnect downpipes, prop, remove radiator, disconnect plumbing, lift engine with a hoist, move it forwards, and then try to tip it, but by that stage it's probably just easier to remove it completely.