RD4021
Watch complete installation tutorials in our Video Gallery.
Basic pack includes:
- 5x clutch/friction discs
- 6x Hardcore steel plates
- 1x Preload shim (Belleville washer)
- 1x Free play delete (fix) shims
Advanced pack includes:
- Basic pack V1 + Bearing & oil seal kit
(You save 10%!)
*Opening tool is necessary for RD4025, RD4026 and RD4060
This clutch stack will provide enhanced lock compared to OEM clutches, saving your viscous coupler as it will take much less load than before. The failure of the viscous coupler in these differentials is one of the main reasons why everyone prefers the ZF mechanical unit. But with this clutch stack now, you don't need to worry about the viscous coupler and waste money on the aftermarket units.
One year warranty!
Almost every E46 M3 Factory LSD unit has problem with the free play in the right drive shaft. That can be recognized by noticing a ‘’tap’’ sound when engaging into 1st gear, and/or the oil leak on right side of the differential. This problem can cause further damage to your differential e.g. clutches and bearings’ premature wear due to the lack of oil. It is highly recommended to address this as soon as possible.
The RacingDiffs FREE PLAY DELETE SHIM will resolve this problem without any modifications for good. Just replace the factory shim, which goes behind the right side gear, with this shim. It’s that simple.
*All parts fits OEM BMW GKN LSD unit without any modifications.
RacingDiffs Recommends Motul Gear Competition 75w140 oil for all products.