will a e30 m3 diff fitting on my 1989 316i

[jonnyboy]

Hi. Ive got a 316i would a LSD off a 1989 e30 m3 fit onto it and as any1 got a idea what ratio they are. Cheers Andy [/quote]

[rich318i]

will fit but the ratios be way off for the gearbox. M3 diffs are 3.25:1 and normal 316i are 4.10:1 check the wiki on here and that will help

[JF008]

My m3 diff is a 3:25, don't know if its a universal fit but it should?

[rich318i]

yes will fit but the gearbox in a 316i and isnt married up to that diff. Install it and you know what i mean thats the best way to find out

[Grrrmachine]

It will physically fit, but you'll have to schedule gear changes in your calendar in advance, due to the ratios.

Arguably, an LSD is utterly pointless in a 316i.

[age]

if you really wanted to run that diff you could fit a gearbox from an e36 iS, it would still hurt the driving experience but not half as much as keeping the e30 box with the m3 diff.

p.s there are 4.1 m3 diffs from uS spec m3's so it may well work without modification to the driveline.

[jonnyboy]

Sorry my fault its a 316 shell but its got a m52 b25 In it with a 1.8 gearbox untill I get hold of a 318is box. I wasn't sure if the drive shafts would bolt up and etc

[age]

my comment still holds for the above but a 328 gearbox would be better for it

[jonnyboy]

If I was to use a 2.8 box would I sill be able to use the m20 clutch and flywheel as I didn't really wana dual mass and would I need to. change the prob

[jonnyboy]

If I was to use a 2.8 box would I sill be able to use the m20 clutch and flywheel as I didn't really wana dual mass and would I need to. change the prop

[Brianmoooore]

M20 flywheel and clutch fit, but the back of the flywheel needs a small amount of machining to clear a couple of sump bolts, and you need to use either an E28 clutch release bearing, or weld a couple of small tabs onto the release forks. Prop needs to be changed.
All you need to know is in the engine swaps forum!
3.25 ratio isn't ideal with either type of gearbox. It's far too numerically low for use with an E30 box, and rather numerically low for use with an E34/36/39 box, where you'll be searching for a top gear.

[HairyScreech]

I have to say a 3:15 with a 1:1 fifth is really not too bad in mine, works out about the same as a 3:91 on a normal car.

With a ZF box or a G250 box (e36 328 or 325/323) a 3:25 should be ok with a 2.8.

With that said it is dependent on what you want from it. A motorway cruiser it would not be.

With regard to the bearing it's better to get some tabs on the release fork, you can use the standard bearing that comes with the clutch then.
Far nicer to just get an fit an off the shelf clutch should you need to.