Two versions of Diff?

[sapote]

I saw 2 different housings (rear opening), and two different clutch stacking designs (more clutch plates). True or false?

[maupineda]

True, some E46 M3 have the Gen2 GKN diff from the Z4M/E9x/E6x

[sapote]

How do we know what production date have the GEN 2 diff?

This eBay seller listed: pulled from 2001 M3 but it’s a Gen 2.
Notice the straight left right wall of the opening.
https://www.ebay.com/itm/12474687561...MAAOSwNQ1gsU89


This one listed as 2006 and has the normal Gen 1 unit. Notice the notched out left/right interior walls of the opening.
https://www.ebay.com/itm/23400799645...cAAOSw54pgnYU3

[sapote]

From RealOEM: 33102282480 is the latest part number applied to cars from 02/01/2002. It supersedes 33102282481(02/18/2002 — 02/02/2015) and 33102282080(09/01/2000 — 11/14/2005).

So majority of cars out there with the "normal" 33102282480 units, as they cannot be the GEN2 diff and I only have seen one or two pics so far on the internet, and those two might not be stock units or someone swapped them from Z4M.

[bjz!]

My car from 2006 with gen2. Changed a long time a go for a custom plated diff.

[sapote]

My car from 2006 with gen2. Changed a long time a go for a custom plated diff.

So most of the 2006 M3 are with gen2 or V2 LSD carriers. I have not found much information about disassemble the carrier to understand how it is different from V1 unit. What happened to your V2 unit?

[bjz!]

So most of the 2006 M3 are with gen2 or V2 LSD carriers. I have not found much information about disassemble the carrier to understand how it is different from V1 unit. What happened to your V2 unit?

Just changed the diff for a plated drexler gt3 rsr rep lsd unit

[sapote]

I have read that to tell which version Diff you have:
* V1 has more plays on the right output flange (as the left flange longer spline shaft drives the pump, the clutch core, and the side-gear, and the right flange shorter spline shaft only drives the side-gear).
* V2 has more plays on the left output flange.

[0-60motorsports]

Can anyone please post pics of the V1 vs V2 diffs if there is an external indicator to tell the difference. Thank you.

[zivagolee]

mrgizmo04 created some great videos during his diff rebuilds

https://www.youtube.com/watch?v=O0jaRcg7T9o

https://www.youtube.com/watch?v=G9pUsKDc5iE

[0-60motorsports]

mrgizmo04 created some great videos during his diff rebuilds

https://www.youtube.com/watch?v=O0jaRcg7T9o

https://www.youtube.com/watch?v=G9pUsKDc5iE

Thats great! Thank you

[sapote]

V2 is harder to open, but the tool is available at Racing Diff for around $100. V2 has the advantage of able to adjust the clutch preload breakaway torque by tightening the locking ring. This is especially useful with higher mileage clutch -- just tighten the ring to get the breakaway torque set again.
For V1, you have to select and add the shim to get the proper 100Nm breakaway torque.

[bigjae46]

I know the V2 LSD unit can provide up to 100% lockup. Not sure if the V1 can.

I've driven both and the V2 is a far superior unit. It is more responsive than the V1. The V1 just feels lazy so it harder to avoid tank slappers. With the V2 you can get way more sideways without spinning and then you can straighten up the car much easier without inducing a tank slapper.

Track use...a clutch type diff is superior because it is more responsive than either the V1 and V2 in locking and unlocking. You can tune the responsiveness with ramp angles with zero downside...you cannot do that with the V1 and V2. You can make the V2 more responsive by increasing the static preload, downside is more turn in understeer and higher clutch wear.

And I believe I don't think either the V1 or V2 lockup under deceleration but I could be wrong.

[sapote]

1. I know the V2 LSD unit can provide up to 100% lockup. Not sure if the V1 can.

I've driven both and the V2 is a far superior unit. It is more responsive than the V1. The V1 just feels lazy so it harder to avoid tank slappers. With the V2 you can get way more sideways without spinning and then you can straighten up the car much easier without inducing a tank slapper.

Track use...a clutch type diff is superior because it is more responsive than either the V1 and V2 in locking and unlocking. You can tune the responsiveness with ramp angles with zero downside...you cannot do that with the V1 and V2. You can make the V2 more responsive by increasing the static preload, downside is more turn in understeer and higher clutch wear.

2. And I believe I don't think either the V1 or V2 lockup under deceleration but I could be wrong.

1. It's great that you had verified the V2 has more lockup capacity than V1. The V2 design confirms this as it has the preload adjusting ring, while the V1 doesn't have a mean to adjust the clutch preload but using the shim, and I don't think the factory measured the preload and then selected the shim to get the 100Nm torque, as the process of adjusting the shim requires measuring the torque, then disassemble the LSD and change the shim is too much labor. I think for V1, they just measured the clutch stack then add the shim to get the a pre-determined total thickness which is not a precise way to have 100Nm preload.


2. The lock up unit (viscous shear pump) works whenever there is a speed difference on the output flanges, in any direction, and so the pump should work under deceleration also (when one wheel turns forward with good grip and the other wheel slips on ice or rotates backward).

[bigjae46]

1. It's great that you had verified the V2 has more lockup capacity than V1. The V2 design confirms this as it has the preload adjusting ring, while the V1 doesn't have a mean to adjust the clutch preload but using the shim, and I don't think the factory measured the preload and then selected the shim to get the 100Nm torque, as the process of adjusting the shim requires measuring the torque, then disassemble the LSD and change the shim is too much labor. I think for V1, they just measured the clutch stack then add the shim to get the a pre-determined total thickness which is not a precise way to have 100Nm preload.


2. The lock up unit (viscous shear pump) works whenever there is a speed difference on the output flanges, in any direction, and so the pump should work under deceleration also (when one wheel turns forward with good grip and the other wheel slips on ice or rotates backward).

If the viscolock units do lockup on decel then it does very little to add stability. I've found that the rear end feels extremely nervous under hard braking. Since I've switched to a ZF clutch LSD the rear end is far more stable under threshold and ABS braking.