Help identify Diff

[Th3importedguy]

What diff is this and does it fit my 91 318i??


Sent from my iPhone using Tapatalk

[Chuck C]

The 7 digits are the part number for the small case diff. It should fit your car.

[Th3importedguy]

The 7 digits are the part number for the small case diff. It should fit your car.

From my research is that 3.91 lsd???


Sent from my iPhone using Tapatalk

[Fsnow]

Usually the little metal tag on the upper left cover bolt will have numbers stamped on it(if it starts with S it's a limited slip) , unless of course it is so rusted that it's unreadable. In that case turn the input and see how many times you have to turn it to get the outputs to make a full rotation. It is small case and will fit. There may also be an S painted on the bottom of it if its limited slip.

[vpilarrt]

A large case diff will also fit the 318i/is. The small case was used because its lighter and you don't need the larger diff since you have less torque with the 318 engine.

[YosemiteSam]

A large case diff will also fit the 318i/is.

I think you mean the Medium case, I don't believe large cases fit in E30's.

[vpilarrt]

I think you mean the Medium case, I don't believe large cases fit in E30's.

You are correct

[ThatOneEuroE30]

What are numbers on this tag??

[TobyB]

Yeah, ^ that.

t