OK, will this Diff fit?????

[L84THSKY]

Saw this on Ebay. seems to mount the same as the 318ti.

I did some research on REALOEM.com. The diff seems to be as he states 3.46:1.

The problem is when I search under 2001 Z3 M, they only used a 3.15:1 diff.
Either way the mounting seems the same, but I can't figure out if this is really from a 2001 Z3 M.

I would love to put that in my 98 318ti.

Did all Z3 coupes/roadsters come with a LSD?
If this diff bolts right on, do the half shafts still need some mods, as in an E30 diff swap?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7948440828&category=33731

[1996 328ti]

I don't think all Z3s came with limited slips.
I believe later M models came with a torsen diff which I believe is better than a clutch pack LSD. Look in the ti notebook section. Their is a writeup on different types of diffs.

[BMWDRIFTER]

Thanks For The Heads Up On The Diff. I Need One For My Car. Just Joking. It Does Appear Ton Have The M Finned Cover.

[maurolin]

yes that one will fit. 3.46 are hard to find.

[Panzer_M]

and anyone got a part # for the diff,

and would the 318ti and 323ti use the same axles?

[L84THSKY]

I could have gone stealth, and just gave the details, but I was trusting you guys. :biggrin:


Thanks For The Heads Up On The Diff. I Need One For My Car. Just Joking. It Does Appear Ton Have The M Finned Cover.

[L84THSKY]

Can I use my stock half shafts, or do I have to change the splines going into the diff?

yes that one will fit. 3.46 are hard to find.

[L84THSKY]

Do you agree that this will fit in a 1998 318ti? I would like to get a consensus. Do you think that the year and model the auction states is correct? I am trying to confirm it, but so far I can't.

I don't think all Z3s came with limited slips.
I believe later M models came with a torsen diff which I believe is better than a clutch pack LSD. Look in the ti notebook section. Their is a writeup on different types of diffs.

[BMWDRIFTER]

Must change shafts. the diff is wider (stronger) so you must use the shorter, fatter, stronger shafts. you will also need to change the flanges to match the axel.

[L84THSKY]

I read the procedure for swapping an E30 6 cylinder diff to a ti. Since this diff is the larger body diff like the diff I am interested in, the concerns should be the same. The procedure said I would need to swap the flanges but not the half shafts. Why would i need to swap the half shafts? I have a low mileage car, and would like to keep as many parts from my car as possible in the swap.


[BMWDRIFTER]Must change shafts. the diff is wider (stronger) so you must use the shorter, fatter, stronger shafts. you will also need to change the flanges to match the axel.

[1996 328ti]

I needed replacement halfshafts. Also had to shim out the ABS sensors.
Also needed a different flange.

[L84THSKY]

OK, so assuming I used the 2001 Z3 M diff, from what cars do I need to look for half shafts? Do the shafts need to come from a Z3 coupe, or are there other models that fit? I would like to get all the parts together and prepared, before attempting this project. If I need shafts and the diff, then I would have everything needed standing by for the swap.

While I'm on the idea of putting a Z3 diff in my car, what other model/year Z3 M or non M cars have a 3.45:1 LSD that would fit my car

I needed replacement halfshafts. Also had to shim out the ABS sensors.
Also needed a different flange.

[KIRASIR]

As far as I know MCoupes/MRoadsters never came with 3.46 diffs, only regular 2.5-3.0 Z3s did. Any 2001+ 2.5-3.0 liter Z3 half shafts should work. I am not sure about the ///M versions or the ones prior to 2001.

1.9l Z3s use the same differential and halfshafts as the ti.

SL


OK, so assuming I used the 2001 Z3 M diff, from what cars do I need to look for half shafts? Do the shafts need to come from a Z3 coupe, or are there other models that fit? I would like to get all the parts together and prepared, before attempting this project. If I need shafts and the diff, then I would have everything needed standing by for the swap.

While I'm on the idea of putting a Z3 diff in my car, what other model/year Z3 M or non M cars have a 3.45:1 LSD that would fit my car

[L84THSKY]

Here is the latest I found. You are correct, M coupes/roadsters never had 3.46 diffs. I did extensive searching through REALOEM.com. The Z3 1.9ltr did have a 3.46 diff, but it was different model than the one up for sale.

The diff I am interested in checks out to be from a Z3 3.0i 1999-2002 models. The part # on the diff crosses exactly to the REALOEM part # for those years.

That makes sense to me for this reason. If you look at the diff rear cover on the one for sale, it DOES NOT have the finned cover that comes on the M/coupe. That "M" that is stamped on the rear (picture) must not mean M coupe/roadster. Then everything else checks out. Any comments?

I have the sellers phone #, and he said to call with any questions.


As far as I know MCoupes/MRoadsters never came with 3.46 diffs, only regular 2.5-3.0 Z3s did. Any 2001+ 2.5-3.0 liter Z3 half shafts should work. I am not sure about the ///M versions or the ones prior to 2001.

1.9l Z3s use the same differential and halfshafts as the ti.

SL

[DustenT]

So.....looks like you'll have a 3.45:1 open diff. for sale, eh? Email me privately at dustent@msn.com and we can discuss pricing.

[L84THSKY]

Maybe, it depends on if I buy this LSD or not, and when I would put it in.


So.....looks like you'll have a 3.45:1 open diff. for sale, eh? Email me privately at dustent@msn.com and we can discuss pricing.

[L84THSKY]

I just got off the phone with the seller. Based on what I have researched and what he is saying, here is the deal.

The casing has a standard part # that ends in 3.15, but the actual diff that is installed inside is marked on the rear cover. The rear cover clearly says 3.46 by part # and ratio listed. The actual guy who owned the car (not the seller) customed ordered the diff with that ratio from Germany. So in the end, he got a diff destined for an M coupe, but customed ordered in a 3.46 ratio. The diff does look perfect, and never opened.




As far as I know MCoupes/MRoadsters never came with 3.46 diffs, only regular 2.5-3.0 Z3s did. Any 2001+ 2.5-3.0 liter Z3 half shafts should work. I am not sure about the ///M versions or the ones prior to 2001.

1.9l Z3s use the same differential and halfshafts as the ti.

SL

[KIRASIR]

What happened to the M cover then?
SL


I just got off the phone with the seller. Based on what I have researched and what he is saying, here is the deal.

The casing has a standard part # that ends in 3.15, but the actual diff that is installed inside is marked on the rear cover. The rear cover clearly says 3.46 by part # and ratio listed. The actual guy who owned the car (not the seller) customed ordered the diff with that ratio from Germany. So in the end, he got a diff destined for an M coupe, but customed ordered in a 3.46 ratio. The diff does look perfect, and never opened.

[L84THSKY]

I have been in contact with Ron Stygar, an M-coupe expert. He is having problems understanding how this can be a 3.46.
I'm gonna call back the seller, and tell him that if I get it and it's not a 3.46, it's going back. I would prefer he open the cover and count the teeth, as Ron suggested, prior to shipping.

I'm wondering about the M-cover too. It does have a big stamp on the rear with an "M"

What happened to the M cover then?
SL

[KIRASIR]

It sounds more and more like a regular Z3 Coupe differential.



I have been in contact with Ron Stygar, an M-coupe expert. He is having problems understanding how this can be a 3.46.
I'm gonna call back the seller, and tell him that if I get it and it's not a 3.46, it's going back. I would prefer he open the cover and count the teeth, as Ron suggested, prior to shipping.

I'm wondering about the M-cover too. It does have a big stamp on the rear with an "M"

[L84THSKY]

I don't care if it's an "M" or not. All I want to be sure of is that it's a 3.46 LSD. Assuming that it is a regular Z3 coupe diff, then the markings seem to support that theory, other than this mysterious "M" stamp.

The second point is, if it is a Z3 coupe 3.46 diff, and the car was an M-coupe, how did the flanges on the diff work with the M-coupe driveshafts, assuming that they use different half shafts?


It sounds more and more like a regular Z3 Coupe differential.

[L84THSKY]

The mystery is solved, thanks to Ron Stygar. The original owner of the diff, upgraded his 3.15 M-coupe diff, to 3.46 Z3 diff. He used the M-coupe cover from his car on the newer 3.46 diff. That leaves the 3.15 M-coupe diff, with a 3.46 Z3 cover as extra. What I have is the remaining parts.

It's still an M-coupe LSD, but it's a 3.15 ratio, not interested!

Now I am trying to get it turned around in transit, via UPS.
Not sure if he can do that.


It sounds more and more like a regular Z3 Coupe differential.