Wich cars have 3.73 LS diff?

[donati]

Hi
Im looking for a rear differential for my '91 M5.

It should be 3.73 ratio, and have LS.

This is the originally installed diff in US E34 M5's newer than 9/91.

But are there other models that share the same diff?
According to my ETK a 530i M30 can also have a 3.73 LS diff,
any idea if it is the same as in the later US M5's?

[TheGeak]

whats wrong with your diff? or do you just wanna change up the gearing?

[donati]

whats wrong with your diff? or do you just wanna change up the gearing?

I want to change the gearing, using a Getrag 265/5 gearbox, and a 3.73 diff.
But im having a bit of a hard time locating the parts.. i spoke to a BMW breaker today, and they have had people on waitinglist for that gearbox for over a year..
I wont give up anytime soon though :)

[Warren N.CA]

You might have an easier time getting a 3.91, as this ratio was used in some auto trans cars. And if you're gunna go through the nosebleed of changing the diff, you'll want to notice some difference, right? (Do get LSD!)


I want to change the gearing, using a Getrag 265/5 gearbox, and a 3.73 diff.
But im having a bit of a hard time locating the parts.. i spoke to a BMW breaker today, and they have had people on waitinglist for that gearbox for over a year..
I wont give up anytime soon though :)

[Martin in Bellevue]

Hi
I'm looking for a rear differential for my '91 M5.

It should be 3.73 ratio, and have LS.

This is the originally installed diff in US E34 M5's newer than 9/91.

But are there other models that share the same diff?
According to my ETK a 530i M30 can also have a 3.73 LS diff,
any idea if it is the same as in the later US M5's?

http://www.bmwe34.net/e34main/upgrade/Recipe.htm

Model OEM ratio Suggested ratio
525i M20 89-91
5 speed 3.73 4.10
525i M20 89-91
Automatic 4.10 4.45
525i M50 All 3.23 3.46
535i 5 speed 3.46 3.73 or 3.91
535i ->6/90 Automatic 3.91 4.27
535i 7/90-> Automatic 4.27 4.45
530i 5 speed (M60) 3.07 3.46
530i Automatic (M60) 3.15 3.46
530i 5 speed (M30) 3.64 3.91
540i ->3/04 2.93 3.25
540i 4/94-> 2.81 3.25
M5 3.6 ->7/91 3.91 4.10
M5 3.6 7/91-> 3.73 4.10

I recently sourced a 3.64 limited slip box from Jim, at autobahn parts in El Cajon, CA, 619-444-2290. He is a friend of & frequents the mye28.com forum. My 3.64lsd came out of an early e34 525. It is showing to be in very good shape. Somehow, it is quieter than the original 3.46 open differential. The price was well under $400 shipped. I did need to have a local gear shop replace the front input yokes. I replaced the output seals & snap rings. I also put 75w90 Redline oil in the box. Redline specifies limited slip & open differential fluids on the canisters. I also replaced the upper rubber mount. If the half shafts are suspect, this is a good time for replacement.

The gearing is delightful. I've used first gear more yesterday, than in the last couple months. The car seems lighter by a couple fat broads, easily.
It sounds like Jim gets many cars through the place. I expect that he'd have a range of boxes for ya.

[donati]

You might have an easier time getting a 3.91, as this ratio was used in some auto trans cars. And if you're gunna go through the nosebleed of changing the diff, you'll want to notice some difference, right? (Do get LSD!)

The original diff in my car is 3.91 (its a Euro M5 3.6'er and a lightened trackcar).

I want to replace the original Getrag 280/5 with the close ratio Getrag 265/5, but if i keep the 3.91 diff, the topspeed will drop to ~218kph, and that is not enough for the Nürburgring. If i can find a 3.73 diff from the US M5's, it will give a topspeed of ~230kph, and that is just about perfect for the Nürburgring.

But since im in Europe, its kinda hard to find parts from US models :)

[donati]

Martin;
Thank you very much, i will contact that company right away to hear if they have the parts i seek, and i'll mention that you pointed me there :)

[Rigmaster]

and alot of 325i/325is used 3.73 LSD's so, if you know someone who is competent at swapping out diff internals, just find an E30/E28 373LSD and use the ring + pinion in your E34 diff case!

Bret

ps- I have not personally done this, but I have spoken to a local shop who specializes in this sort of thing, he said "it's not that hard to do, but if you don't get it right, it will howl like a banshee"........





Hi
Im looking for a rear differential for my '91 M5.

It should be 3.73 ratio, and have LS.

This is the originally installed diff in US E34 M5's newer than 9/91.

But are there other models that share the same diff?
According to my ETK a 530i M30 can also have a 3.73 LS diff,
any idea if it is the same as in the later US M5's?

[Paul in NZ]

:D

[632 Regal]

change all flanges and the mounting bracket.

I don't know just trying to figure this stuff out myself.

[Rigmaster]

OOPS, sorry, missed the fact that he's working with an M5. I know that the ring + pinion from a 6 cyl E30/E28 or E30 M3 are the same as the smaller E34 gears (6 cyls + 530i). But I also know that the M5/540i diffs are different- not sure about the ring + pinion.

Bret