E30 Differential

[E30 Ray]

I need to change my stock diff in an 89 325is to a 4.10 diff. I see them for sale from BMP for a pretty steep price. Can I visit my local junk yard and use one from a crashed M3? Would that be legal in IT? Or should I pull the one I have and have it rebuilt with the improved ratio.

--Ray

[BMW RACER]

Ray, The M-3 should be the same as the 325i automatic, you will be suprised how many are LSD, check the tag on the back for the ratio, and should have an "S" on top if its a LSD.
Happy hunting

[chuck baader]

shouldn't have any problem finding one in the 300-400 neighborhood. try to find one locally, though, since shipping on 75# is steep...chuck btw, yes, the m3 fits, as does any e30 unit.

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Chuck Baader
SEDIV ITS #36
E30 BMW

[zracer22]

Ray
I payed $225 for one on ebay. As far as legallity, the M3 LSD is legal because it is the the same housing as the 325i, onlt yhe ratio is different.

[James Clay]

All M3 are 4.10, most 325i are 3.73 but 4.10 was an option and I have seen a few on the 89-91 cars, possibly standard in the automatic. The diffs start out at 25% static lock from the factor and drop as the clutch plates wear out. When we build a diff, we can build up to 40% locking with the stock setup and add more discs for higher amounts/better clutch wear/smoother transitions if needed. Used diffs are certainly a good option, but not the same as a rebuilt diff from a race shop.

James

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James Clay
http://www.bimmerworld.com
Engineered BMW Performance
BMWCCA/SCCA Racecar Rental
Genuine OEM and Used BMW Parts
(540) 639-9648
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[Bruce Shafer]

I believe that some E30 325i models with automatics (possibly convertibles) came with a 4.10 differential. I was able to pick up an open 4.10 for $200 at a local yard. Get it welded and you have an almost indestructable unit for next to nothing.

[E30 325i]

So let me get this straight;

LSD 4.10 diffs were standard (or at least an option)on automatic 1989-1991 325i and 325i convertibles?

If so, is the 4.10 LSD found in those 325i and 325i convertibles the SAME EXACT one as in the E30 M3? Thanks.

[This message has been edited by E30 325i (edited December 05, 2002).]

[Bruce Shafer]

Open 4.10's were found on 325i convertables with automatics, 325is's had the 3.71 LSD, E30 M3's had the 4.10 LSD. I don't have a clue what was in the garden variety 325i.

All 6 cylinder E30's used the same differential housing.



[This message has been edited by Bruce Shafer (edited December 05, 2002).]

[djsmith]

I have the internals from a LSD from a BMW e30 diff. I had it removed when I upgraded to a Torsen. You can use it to turn any e30 diff into a LSD.

You can have it for $200 + shipping.

[email protected]



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Derek Smith
2002 WSC P3 Champion
2001 ICSCC Novice Driver of the Year
2001 ICSCC EIP Champion
#42 BMW 325is White/Blue

[JOESELLSVW]

4:10 diffs are around. I noticed that you are in New Jersey, you might want to chaeck in with a few friends of ours at VAC Motorsports. thry just built a Quaife unit for us for a customer car fro signifgntly less than other shops. Ours was a little more complex because we didn't have a LSD core and needed the ring and pinion from the M Coupe. Tony runs in the WC series as well as a big supporter of BMW CCA. Good guys. Give them a call and tell them that I Joe from West Chester sent you. www.VACmotorsports.com

[chuck baader]

have an excellent 4.10 ring and pinion if anyone is interested. [email protected]

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Chuck Baader
SEDIV ITS #36
E30 BMW

[James Clay]

All 6 cyl US models have exactly the same diff. the 325ic did have a LS option, same diff as the E30 M3.

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James Clay
http://www.bimmerworld.com
Engineered BMW Performance
World Challenge/SCCA/BMWCCA Racecar Rental
Genuine OEM and Used BMW Parts
(540) 639-9648
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