The MMX Rear Diff Raised Poly Bush is a direct replacement for the factory rear differential mounting bush on the BMW G8x M2, M3 and M4. Set to the OEM height position, it tightens up the connection between the differential and the chassis at the rear mounting point, reducing movement under load without changing the vehicle's geometry.
The same bush also solves a problem specific to lowered cars. Lowering a G8x M2, M3 or M4 changes the geometry of the rear axle, placing the driveshafts under an angle they were never designed to run at. This accelerates wear on CV joints and axle shafts, and increases heat build up at the diff. Set to the +10mm Lifted position, the bush's centre section raises the rear mounting point, restoring correct driveshaft geometry and taking the strain off the drivetrain.
Fitted at the front, the MMX Front Differential Lift Mount / Cradle (MMR55-1604) works to the same OEM or Lifted position, and together the two form a 3-point setup. For a full 4-point setup, a second bush is fitted alongside the MMX Dual Differential Mount (MMR55-1606), also set to match the same height throughout.
What makes the bush unique is that one part covers both applications. It isn't a raised version and a stock version sold separately — it's a single bush where the centre section position at the point of fitting determines whether it's simply reducing movement, or correcting geometry on a lowered car.
Two-position centre section, OEM height or +10mm Lifted
Direct replacement for the factory rear differential mounting bush
Reduces drivetrain movement under normal and increased torque loads
Lifted position corrects driveshaft geometry on lowered vehicles
Reduces heat build up and premature wear on OEM or aftermarket axle shafts
Suited to road and track use
Designed to work with the MMX Front Differential Lift Mount / Cradle (MMR55-1604) and MMX Dual Differential Mount (MMR55-1606)
