late 318i half-shafts vs 325 half-shafts

[Cyrix2k]

Are the half-shafts in a '91 318i different than a 325i/e as far as strength? I have a 24v swapped '91 318i that's soon to see a turbo and want to make sure nothing blows up. The small case diff will be replaced with the 2.79 medium case from my 325e. Thanks!

[b*saint]

The flanges are different if you have a small case diff.

[Holland]

Flanges have nothing to do with it. And I'm pretty sure all late model axles are the same. It's 85 and earlier you have to worry about.

[Cyrix2k]

The flanges are different if you have a small case diff.

From what I heard, the axles bolt right up to a medium case - the axle flanges stick out on the small case to make up for the smaller dimensions.

Flanges have nothing to do with it. And I'm pretty sure all late model axles are the same. It's 85 and earlier you have to worry about.

Can you elaborate on the "85 and earlier" problems? My goal is to swap an '85 325e non-abs diff into a '91 318i abs car. I'd like to install the 4.10 from the '91 in the '85 too, but I might buy a more suitable diff. I'm pulling the go fast parts off the '85 and putting them on the '91 which has a good body and interior, then selling the '85 as a running 24v beater.

[MR 325]

Yes, late 318 axles are the same as all 325i/is/ic cars.

[irish44j]

I have an '85 318i with small case, and I am using axles from a later ABS car. I don't recall having to change anything.....

[jeffnhiscars]

From what I heard, the axles bolt right up to a medium case - the axle flanges stick out on the small case to make up for the smaller dimensions.

Can you elaborate on the "85 and earlier" problems? My goal is to swap an '85 325e non-abs diff into a '91 318i abs car. I'd like to install the 4.10 from the '91 in the '85 too, but I might buy a more suitable diff. I'm pulling the go fast parts off the '85 and putting them on the '91 which has a good body and interior, then selling the '85 as a running 24v beater.

The early non-ABS cars will be missing the ABS sensor ring so while the shaft will fit in your 91, your ABS will not work as it should.

I have an '85 318i with small case, and I am using axles from a later ABS car. I don't recall having to change anything.....

Typically you have to knock the ABS ring off to get it to fit in the early non-ABS hub as they are shaped differently.

[Cyrix2k]

wait, is an ABS ring/sensor integrated into the diff??? I just want to swap the diffs, not the axles. I'd prefer to keep ABS, but I guess it's not that big of a deal if it doesn't work. LSD > ABS.

[jlevie]

The ABS speed sensor rings are on the half shafts. The differential has nothing to do with ABS.

[Holland]

The ABS speed sensor rings are on the half shafts. The differential has nothing to do with ABS.

This. OP will have zero issues swapping diffs.

I have 85 325 trailing arms in my 318, and I got a set of ABS axles a while back. While I thought all I had to do was remove the ABS ring, I found out that the splined end was an entirely different shape and would contact the inside of the trailing arm. The later axle was a square shape, and the recess in the trailing arm was a rounded shape.

[irish44j]

The early non-ABS cars will be missing the ABS sensor ring so while the shaft will fit in your 91, your ABS will not work as it should.



Typically you have to knock the ABS ring off to get it to fit in the early non-ABS hub as they are shaped differently.

you're right....but I'm also using 325i later hubs/LCAs so didn't have to :)