ZF Limited Slip Differential often found in BMW E30, E36, E34, Z3 and such has cast iron parts that often fail under increased load/power. When you change the ramp angle to 30°/30° or 30°/60°, there is an increased risk of the differential cap breaking.
So a reinforced billet steel cap is a permanent solution. By installing it, you will avoid a cap failure for good. You have a LIFETIME WARRANTY on it!
The cap is made from the highest quality tool steel, hardened and nitrated for the ultimate resistance and longevity.
Reinforced bolts are included as well, which won't suffer the internal stripping problem as the originals.
The cap is highly recommended for drifting and any type of racing.
*Please note that the 188mm cap is made to fit with a 4 clutch pack. It is 4 mm shorter than the original, so a minimum number of clutch plates is 3.