rear diffs m3 & 325i are they the same

[E30cosworth]

are the M3 & 325i lsd rear diffs the same

could i use a E36 M3 diff instead of a E30 M3 diff?

[Simon]

E30 M3 and E30 325i diffs are essentially the same, except they are different ratios, M3 will be 3.25 (3.15 on some evo variations), and 325i will be 3.64 & 3.91, so they will straight swop.

To fit E36, I believe you will need to swop the whole rear assembly.

[maxfield]

No the E36 M3 won't fit on your car.

You bought paul simons old car?

Any E30 LSD will fit on the back of the M3 axle.

[Andy335Touring]

E30 M3 and 325 fit the same but the E36 M3 won't fit.

Most Euro E30 M3 diff's are 3.25, US ones are 4.1 i think ?

325 Sport pre-face lift diffs are 3.64, post face lift Sports are 3.91, fairly rare but you can get a 3.73 from a non-sport 325.

HTH

Andy

[Andy335Touring]

Too sloooooooooooooooooowwww

[maxfield]

yes us were 4.1 and rare as rocking horse poop

[Simon]

yes us were 4.1 and rare as rocking horse poop

Yeah, but crap too, as they didn't have the dogleg box either.

[E30cosworth]

ok thanks so if i fit a non M3 diff it'll be a higher ratio so have quicker acceleration but less top-end

It not that my M3 diff is broke just need to have it fitted with new bearing does any1 know where i could get this done?

[Andy335Touring]

ok thanks so if i fit a non M3 diff it'll be a higher ratio so have quicker acceleration but less top-end

yes

[E30cosworth]

and also which diffs have an LSD?

i'm i right in thinking its just the M3 & 325i/sports that have lsd as standard

[Simon]

and also which diffs have an LSD?

i'm i right in thinking its just the M3 & 325i/sports that have lsd as standard

As standard yes, but an LSD was optional on all E30's.

[Brianmoooore]

Any E30 could have had a LSD as a not very expensive option. It's just a pity that the yuppie posers who bought E30s back in the eighties knew so little about cars as to not specify a LSD (or aircon, for that matter).

[E30cosworth]

right ok cool i'm learning as i go along here about BMW's i know plenty enough about Cossie's just not alot about BMW running gear

where would be best place to get diff bearing and seals done or do you reckon i could do it myself i'm pretty handy with the mechanical side of stuff

you peeps are right helpful on here it would take an age to get info like this on other sites

You bought paul simons old car?

if thats Username: GRACELAND off passionford then yes it his old car

[Andy335Touring]

New seals you can sort easily your self except the input shaft seal, rebuilding is a specialist job though

[Brianmoooore]

New seals you can sort easily your self except the input shaft seal,

You can do this one OK as long as you mark exactly where the input shaft nut was torqued up to. Do it back up with a torque wrench and check that it torques up at exactly the same position.

[Andy335Touring]

ah right, i've always been scared to touch it incase i nacker the diff

[E30cosworth]

right ok thanks thik i will just get GEARBOXMAN to sort it

[k]

Have used Stevensons in Preston 01772 723325 for gearbox and diff rebuilds in the past, they're pretty good, and not to far for us in Cumbia.