Differential

Post Sun Apr 01, 2012 3:30 pm

Hi people this is my first post hear been having a look about the site though and it is a great job, credit to those in charge. So this will be my first question on many i would guess... having just got my first e30 (325i) not sport. i will be looking to upgrade the diff in the car what diff should i be on the look out for? should it be one that has just came out of a 325 sport or is there any other one's i should be keeping an eye for ? are there any others non e 30 that could work? I have to took hold of the car yet just wating on it to be collected at the min but when i do get it i will post a few pictures

Post Sun Apr 01, 2012 4:33 pm

Hello and welcome to the zone....

whats the reason behind the diff replacement/upgrade ?

Post Sun Apr 01, 2012 4:44 pm

If you stick the title of this thread into the Wiki, you get your answers

http://www.e30zone.net/e30zonewiki/inde ... fferential

That'll explain what diffs were fitted to each car, why the ratio is important, and links on how to swap them over if needed. What more could you want?

Post Sun Apr 01, 2012 9:45 pm

Grrrmachine wrote:If you stick the title of this thread into the Wiki, you get your answers

http://www.e30zone.net/e30zonewiki/inde ... fferential

That'll explain what diffs were fitted to each car, why the ratio is important, and links on how to swap them over if needed. What more could you want?

Grrmachine, I had a look at the wiki link it didn't really answer my question in relation to what other lsd's fit the 325i i'm new to car work all together so just trying to gather as much info as i can.

Kam 325i, the reason is im looking a lsd rather than an open diff and looking to know were is best to look what models ect as i understand the 325i came with an open diff rather than an lsd?

Post Sun Apr 01, 2012 10:09 pm

The LSD diff was an opition on all 325i's, and standard on the sports.

best place to look for one is in the for sale section on here or on ebay....

http://www.ebay.co.uk/itm/BMW-E30-3-64- ... 2c64555a3f

http://www.ebay.co.uk/itm/BMW-e30-325i- ... 2a1baf8d8b

http://www.ebay.co.uk/itm/E30-BMW-LSD-l ... 3372e72361

Post Sun Apr 01, 2012 10:25 pm

So the 325i that i bought might have the lsd, cant wait till it get hear to see it in the flesh i know fine well that it needs loads of work but i cant wait to get started on it.... would i be right in saying that if it is a lsd it will have the letter s placed infront of the numbers on the diff?

Post Sun Apr 01, 2012 10:35 pm

dedemccaw wrote:would i be right in saying that if it is a lsd it will have the letter s placed infront of the numbers on the diff?

That is correct.

As you are looking at the backplate on the diff, the tag should be on the right hand side, on the middle-ish bolts.

Post Mon Apr 02, 2012 2:03 am

To check its a slipper real easy, jack one side of the rear up and rotate the rear wheel. If you cannot turn it then the diff is an lsd, if the wheel can be turned its open.

Or jack both rear wheels up and turn 1, on an open dif the opposite wheel will rotate the other wa. Lsd, both will tuen in the same direction.

Hope this helps

Post Mon Apr 02, 2012 5:33 am

dedemccaw wrote:Grrmachine, I had a look at the wiki link it didn't really answer my question in relation to what other lsd's fit the 325i

There's no OTHER LSDs that fit the 325i. 325i diffs fit the 325i; all the other diffs are too weak or high-ratio'd to be of any practical use.

The idea of the table is to show what ratios were fitted to what car, and as you can see, the LSD was just an optional extra (or standard on sports models). So there's never any guarantee that a car has an LSD fitted; especially 20 years after it left the factory.

Post Tue Apr 03, 2012 12:11 pm

Grrrmachine wrote:
dedemccaw wrote:Grrmachine, I had a look at the wiki link it didn't really answer my question in relation to what other lsd's fit the 325i
There's no OTHER LSDs that fit the 325i. 325i diffs fit the 325i; all the other diffs are too weak or high-ratio'd to be of any practical use.

Apart from those fitted to E28 528i's. Fit the 325i rear cover and outp[uts and it goes straight in. They have nice ratios as well - 3.25 (dogleg gearbox) and 3.45 for standard cars. I've seen a couple of 3.64's as well.