Doing a diff rebuild.

[Arith2]

You'll need a press obviously. 20 ton is preferred. Definitely use Motul. I wouldn't use their seals. It is also good to have a second set in case you booger one up on install or have to remove if you realize you did something wrong. I used a dremel for my races and it worked great. The small cutting wheel made it easier. Have you ever rebuilt a diff?
Also just get the Castrol high velocity grease. It's what we use at my dealer.

[SteelGreyM]

You said it had more plays on the right side flange, which means it is V1 diff and not V2 which will not work for yours.
The top pic is the clutch stack
The middle is shows a cup spring shim on the side-gear. I prefer to use flat shims (McMaster Carr) instead of the convenience single cup spring shim as the latter might not keep its shape long.
The bottom are bearings for the pinion (you might not need to do) and two carrier bearings.

Now things are starting to make sense! So I will need the v1 kit. And specifically that middle part?

[sapote]

To reduce the play I would need to use something like https://racingdiffs.com/products/bmw...34105144672391 this right? The advanced v2 kit.
!

You said it had more plays on the right side flange, which means it is V1 diff and not V2 which will not work for yours.
The top pic is the clutch stack
The middle is shows a cup spring shim on the side-gear. I prefer to use flat shims (McMaster Carr) instead of the convenience single cup spring shim as the latter might not keep its shape long.
The bottom are bearings for the pinion (you might not need to do) and two carrier bearings.

[SteelGreyM]

When or under what condition the clunk happened? Happened when step on gas taking off could mean the LSD clutches slip causing the side-gears clashed to the spiders hard and the clunk. In this case, reducing the plays between the side-gears to the spiders will help.

Version 1 diff (pre-2004 I think) with shorter right side shaft has more radial plays leading to leaky seal faster. Version 2 has the shorter left side shaft.
Reducing the side-gears plays is not a tedious process (rebuilding ring/pinion is and requires perfect alignment for quiet ride). Just shim up the side-gears to reduce the plays, and replace the shaft seals.

I am getting a clunk when I get on and off the gas as you mention. Additionally, I have the low speed shifting clunk however I think that is normal M clunk. Sometimes it clunks if I go from neutral to first (like at a red light).

To reduce the play I would need to use something like https://racingdiffs.com/products/bmw...34105144672391 this right? The advanced v2 kit.

Also, while I am here. Can anyone recommend a CV joint grease for me. Would like to regrease mine while it is out. I know the BMW one is black. https://www.fcpeuro.com/products/bmw...0g-83190447919

Is this is?^

Thank you!

[sapote]

https://www.youtube.com/watch?v=F7QTGKCcWVU
I am chasing a clunk coming from the rear of my car. .

When or under what condition the clunk happened? Happened when step on gas taking off could mean the LSD clutches slip causing the side-gears clashed to the spiders hard and the clunk. In this case, reducing the plays between the side-gears to the spiders will help.

Version 1 diff (pre-2004 I think) with shorter right side shaft has more radial plays leading to leaky seal faster. Version 2 has the shorter left side shaft.
Reducing the side-gears plays is not a tedious process (rebuilding ring/pinion is and requires perfect alignment for quiet ride). Just shim up the side-gears to reduce the plays, and replace the shaft seals.

[SteelGreyM]

I believe bad sub bushings are a culprit of wheel hop.

Thanks for input. But mine are solid.

[jet_dogg]

I believe bad sub bushings are a culprit of wheel hop.

[eacmen]

Another question. I know the passenger side normally has some play in it. Do you think this would cause a clunk? Or should I go through with simply doing the bushings (front and rear) and toss it back in to see if it solves it. The bushings were not really in bad shape if I’m being honest (from what I could tell).

Not sure. Wish I could help.

There are some that claim the clunk is from free play and the free play kit fixed it. Then some have had bad experience with the free play kit.

I either don’t have a clunk or it doesn’t bother me. The times I have thought I had the “M clunk” it turned it to be something else.

Maybe take a video of your free play?

[SteelGreyM]

Oh! And I can have pretty bad wheel hop on launches… really is a 50/50 if I get bad wheel hop or a nice launch.

Could this be the issue?

[SteelGreyM]

If it were me I would buy a rebuilt unit from diffsonline and send the old one back as core. A diff rebuild can be a pretty tedious process.

https://diffsonline.com/

Another question. I know the passenger side normally has some play in it. Do you think this would cause a clunk? Or should I go through with simply doing the bushings (front and rear) and toss it back in to see if it solves it. The bushings were not really in bad shape if I’m being honest (from what I could tell).

[eacmen]

If it were me I would buy a rebuilt unit from diffsonline and send the old one back as core. A diff rebuild can be a pretty tedious process.

https://diffsonline.com/

[SteelGreyM]

https://www.youtube.com/watch?v=F7QTGKCcWVU

Hi all, been a while.

I am chasing a clunk coming from the rear of my car. No it is not my subframe. I originally thought it was the differential bushings. I bought those and installed them. However upon pulling the diff I noticed I had a lot of free play coming from the passenger side output flange area (I think that is what its called). You can see my exact issue if you watch the first 30 seconds of the above linked YouTube video. My diff has 150k miles.

Basically, I think I am going to end up doing a full rebuild as shown in the YouTube video. Was hoping someone online could provide some input on the job as well as a reliable and good source for the needed parts.

Any other parts I should buy? should I relpace the clutch packs while im in there? Thanks for your help.