These transmission bushing enforcer cups are great if you're looking to stiffen up your transmission mounts without adding noise into cabin. Machined from 6061 aluminum, these are meant to be used with E21 transmission bushings (not included). Using those bushings is an upgrade (because they are already stiffer then most OEM BMW units), but these aluminum cup are designed to deflect load over a greater area.

This will keep the transmission and shift linkage where they're supposed to be. This will then eliminate the possibility of a mis-shift caused by the linkage binding. On E30 DOHC swaps, (M50, S50, etc etc) these help prevent engine/transmission movement to ensure that your fan does not dig into the radiator on this very tight swap. Rubber mounts without enforcer cups may rip under heavy braking causing this to happen. Comes with a lifetime warranty.

Compatibility

Fits these models when equipped E21 transmission bushings:

• 1 series E82, E88 (M Coupe, 135i, 128i)
• 2 series: F22 (2014+ non x-drive), F87 M2 (2016+)
• 3 series: E21, E30, E36, E46, E90, E92, F30 (non x-drive), F80 M3
• 4 series: F32 (non x-drive), F82 M4
• 5 series: E39
• 7 series: E38
• Z series: E85, E86, E89, E37, Z3s, MZ3s
  
  

Benefits of E21 Transmission Bushing Enforcer Cups

• Limits engine/transmission movement
• Quietest option that will not allow movement and will not transmit noise into cabin
• Does not allow transmission movement under heavy breaking or acceleration
• Lifetime warranty
• Transmit more power Oil resistant
• Compatible with E30, E36, E46, E90, E92, E21, E34, E39, F30, F32, F22, F80, F82, and F87
• Price is for a pair (2 units). Enough to do 1 car.