Intake system?

[mkcman17]

check the silver metal tag on any given diff. if the ratio number is preceeded by an 's' it's an lsd. for instance, manual 325is's originally came with s3.73 tags and auto 'is's were s4.10...

or at the JY spin one wheel and watch the other...easiest method, plus you can hear obvious clunks.

as a note, i've heard only about half of 91 318is's had (small case) s4.10, the other half were open. not sure how much truth to that there is though..

[blefevre]

Yeah you can switch them. The small case ones are weaker though. But yes, you pretty much need to get under the car. LSD's and open diffs were pretty much offered in any version/transmission of the E30's.

[Bene]

yeah, if I do spring for a diff I'll made damn sure I know what I'm getting. Just wanting to know what to keep my eye out for when hunting in JYs

also found this after my last post:

http://en.wikipedia.org/wiki/BMW_E30#Drivetrain

when looking at that chart, it looks like 4 and 6 cyl cars have different sized pumpkins, are they interchangeable?

[Bimmerman325i]

do all e30s have the same diff housing?


by looking at models #s, is there anyway to know if it's a LSD without having to get under the car?

Since they're all 20+ years old now, no, don't trust it.

iS cars more often than not had LSDs, but there's no set rule.

ALL M3s had LSDs.

[Bene]

do all e30s have the same diff housing?


by looking at models #s, is there anyway to know if it's a LSD without having to get under the car?

[blue325es]

Very nice.. Saves me some hassle

[mkcman17]

Swapping a diff is pretty simple. As long as you stay medium case the driveshaft/rear geometry wont change.

[blue325es]

And I'm assuming a bigger driveshaft is required

[blue325es]

Ya that's my plan.. Definitely gonna do a 3.73.. Where's autosport werks

[blefevre]

I don't think there are rebuild parts either.

OP: Don't put a 4.10 in an "es". I would do a 3.73 in that car. I still love my 4.10 in the 325iS. Sure it's loud at 80 but w/e it's a blast to drive.

[gmyers395]

The 4.10s they have are lsd. And I don't think they have rebuild parts but don't quote me.

[iamsam]

Im pretty sure they have a couple 4.10 diffs laying around Autosport Werks that they would let go. I don't think they want too much for them either.

I need to rebuild my 4.10 LSD BAD, it is wailing loud. Do they have rebuild parts?

[Bimmerman325i]

Personally, i'd rather have a LSD 3.73 than an open 4.10, having had a 4.10 LSD. The gearing change is nice on the street (not so nice on track or autox), but these cars drive remarkably different with an LSD.

[gmyers395]

Im pretty sure they have a couple 4.10 diffs laying around Autosport Werks that they would let go. I don't think they want too much for them either.

[colorado_cabrio]

cabrio has 3.73, but I'd assume it's an open diff