LSD Diff backlash

[bazar01]

I have a driveline slack when I accelerate and decelerate.
So far I have done these.
1. Replaced the CV axles. Used axles have no radial play.
2. Moved the center bearing forward by 1/4 inch
3. Replaced the guibo.
4. U-joints on drive shaft are good.
I can still feel the driveline slack.

It looks like the slack is inside the diff with LSD.
238k miles on body.

Is it possible the clutches and dog ears are worn or have worn the grooves where the dog ears reside in the LSD carrier?

Where can I get LSD clutch rebuild kit?
What is the diff size?

Thanks.

[bazar01]

I am going to check the differential bushing tomorrow. It could be deteriorated.

[bazar01]

Took the diff cover off to replace bushing. Bushing is deformed and causing diff housing up/down movement.
I replaced it with new Powerflex urethane type bushing.
I am amazed. No more clunking in the rear.
Although the diff is bolted to the subframe, the sheet metal is so thin it is flexing as I raised the diff with a floor jack while aligning the bushing to the hole.
One problem solved.
Subframe bushing next.

[L84THSKY]

I'm getting some clunking sound when I take off from a dead stop. Wonder if the problem is the same as yours. Getting rid of the car in the near future, so not a big deal

Originally Posted by bazar01

Took the diff cover off to replace bushing. Bushing is deformed and causing diff housing up/down movement.
I replaced it with new Powerflex urethane type bushing.
I am amazed. No more clunking in the rear.
Although the diff is bolted to the subframe, the sheet metal is so thin it is flexing as I raised the diff with a floor jack while aligning the bushing to the hole.
One problem solved.
Subframe bushing next.

[bazar01]

Answer to the questions:
1. I used Powerflex urethane diff bushing
2. Clunking when taking off from dead stop could mean a lot of things
- Loose CV axles
- Loose propeller shaft splines and u-joints
- Deteriorated guibo
- Dual mass flywheel loose or separated
- Deteriorated Diff bushing
- Play in transmission input and output shafts
- loose center bearing

If you are getting rid of the car, just be honest to the buyer and just pass them on to the next owner.

[BimmerBum]

If you are looking for diff rebuild parts http://www.bimmerdiffs.com/ is your source. Jonathan just rebuilt the diff for my Club Sport. I have not installed it yet but I have seen him work and he knows what he's doing.

[CosTick]

which bushing did you end up going with? im about to do this same job on my ti and i wanted to go poly, but wasnt sure about density etc...

[M-technik-3]

He mentioned he used a powerflex.

[MINIz guy]

I've been reading up on this topic lately since I just bought a 4.44 LSD and want to convert it to a 3.45 LSD.

I sent an email to Ireland Engineering and got the following information. The clutch discs and the dog ear plates are the same in all 168mm differentials after the E21. Therefore, I believe that 33141203806 is the correct part number for the clutch discs and that 33141203804 is the correct part number for 2.0mm thick dog ear plates. Having the original BMW part number makes the clutch disc refresh much cheaper than the Bimmerdiffs kit. There was a switch in parts in 09/1978, so that is probably when BMW went from 21T to 23T.

[bazar01]

Hey MINIz where do you plan to get the cheaper clutch and dog ear replacement parts? Is it from Ireland Eng'g? How much cheaper?
Thanks.

[MINIz guy]

The part numbers I listed are just BMW part numbers. You can get these from any BMW dealer or online retailers such as ECS Tuning.

I just sent another email to Ireland Engineering about the tooth count on the clutch discs. They did backtrack a little on being definitive on tooth count for the clutch discs and told me to email another company that has more experience. So, I think my previous post may have a premature conclusion on the clutch disc part number.

The dog ear plates should be the right part number. They are the same for all 168mm differentials. No tooth count difference or anything on them.

I'll report back on an answer to the clutch discs soon.

[spidertri]

Bimmerdiffs clutches might be more expensive but they are, supposedly, a more robust clutch material. They should have greater durability under track/autox situations.

Now that I think about it, aren't the 168 clutches NLA from BMW? I looked into all this when I was refreshing my diff. Most sites still list parts until someone orders it and they can't get it, just FYI.

[MINIz guy]

Contacted Diffsonline per the recommendation of Ireland Engineering.

They told me that BMW never offered 168mm parts for the E36 differential. I guess there is a 21T and 23T difference that Ireland Engineering didn't know about. Drexler is the company that still makes the clutch discs and dog ear plates for the 168mm small case differential. Diffsonline sells each clutch disc for $65, so a better price than Bimmerdiffs at $76 each.

I also have a strong feeling that the dog ear plates are still the same from the E21 to the E36. Bimmerdiffs doesn't differentiate between 168mm dog ear plates, and there is only one part number for them in all E21 years. When I tackle this project in the spring, I'll call up my local BMW dealership and ask about their return policy. If they allow for returns, I'll buy new dog ear plates using the E21 part number and compare it to the plates I remove from my LSD unit.

I'm not sure if clutches are NLA. The E21 ones can be ordered by ECS Tuning and the part numbers on RealOEM don't have anything signifying the part has "ENDED". I haven't bothered to call and verify as I'm 5 months away from doing this project. It also is a moot point since it seems that you cannot use E21 clutches on the E36 168mm differential.

[spidertri]

getbmwparts.com says part discontinued when you search for the clutch p/n.

They are ZF differentials, whoever was the supplier could certainly still make them. Most of the clutches and dog ear plates were used in porsche differentials too. There were a few different thickness dog ear plates available from porsche.

[MINIz guy]

Interesting. At least the dog ear plates are still available for $25 on that website.

Drexler is the company that still makes 168mm clutches, according to Diffsonline.

That is true that they are ZF differentials. However, it is mainly the 188mm differential that is documented. I'm not sure which Porsches used 168mm differentials. So, I think it will be a bit difficult trying to chase down the part numbers for them. I certainly don't know enough and don't have the bank account to do so.

I sometimes wonder if I'm fighting a losing battle modifying my 318ti. It won't ever be competitive in STX and I don't know how much more I have to sink in before I'm happy with where it is at.