Author Topic: E30 drive shaft length? (Read 7248 times)

longtallsally · « **on:** February 28, 2010, 03:22:52 PM »

So I'm sorting out some vibrations in my 318is and have a line on a good rebuilt full drive shaft. However, it is coming from an M20 325is. In other words a longer tranny and a longer diff.

My question is, will the 325 shaft work in my 318? I know there is play in the slip yoke of the shaft and I think I remember that there are 2 sets of bolts in the chassis to allow for stuff like this, but just don't want to get it wrong with shipping and the like and would prefer not playing mix and match with old and new.

Thanks!

longtallsally · « **Reply #1 on:** March 03, 2010, 01:37:57 PM »

No love? I just replaced the half shafts and all the bushings and shock mounts are all in good shape, so I'm now pointing to the driveshaft being my culprit.

DesktopDave · « **Reply #2 on:** March 03, 2010, 02:57:17 PM »

I'm sure the diff is the same length, or close enough that a pry bar could persuade it in. Let me see if I can get some other details for you. I'm sure someone has this info...they'll post, don't worry. If I get to it, I'll have one out sooner or later to tell you for sure. I'm doing an auto M20 eta to manual M20 i swap this spring. Slow to fast, eh?

Can you call the shop & have them measure the shaft from front to CSB & from CSB to rear flange?

I looked at RealOEM.com, it lists 1483mm for the 325is shaft. No similar info on the 318is shaft length.

dinu.negrean · « **Reply #3 on:** March 03, 2010, 03:41:25 PM »

I have checked for my E36 when i considered swapping with the m50b25. For M42b18 it is 1564mm and for m50b25 it is 1512. 5.2cm difference. I'm sure for e30 they are not the same length.

longtallsally · « **Reply #4 on:** March 04, 2010, 10:32:42 AM »

Thanks guys.

So the car the shaft I would get is coming from a 325is as I mentioned. The PNs are different on realoem, of course.

The primary differences between them is that the "small" case diff is supposedly 10mm shorter than the "medium" case diff. However, the transmission for the 318 is shorter than the 325.

I think it might be that they are about the same length but the different holes I mentioned would have to be used that are in the chassis to compensate.

I'm just not sure and I hate to buy the wrong part. I've lined up where I can get a reman one for double what the one that I can get from a member of another forum (which is still half what most will quote) that I know will be the correct size. I'm starting to wonder if it would be better to just get the correct one to start with...