Extended Studs/Spacers VS Offset Differential Bushing
When installing our 12mm Raised Subframe Bushings, the factory differential bushing will no longer line up with the mount on the E30 chassis. Garagistic offers two solutions; an Offset Differential Bushing or an Extended Stud/12mm Spacer Kit.
Extended Diff Studs and Spacer Kit
Our extended diff stud and 12 mm spacer kit is out preferred method of solving this issue. The spacers included in the kit allows you to use a centered factory or aftermarket differential bushing that maintains the factory drive line geometry. Removal and Replacement of the differential is simplified since the studs act as an alignment guide vs blindly poking through the subframe with the factory bolts and praying to find threads as you maneuver the hefty E30 differential into place. These will also work with reinforced rear subframes.
Offset Differential Bushing
The offset differential bushing uses the factory M10 hardware and re-positions the differential up 12mm due to the raised subframe bushings. The necessary offset design does place less material between the diff cover and bushing race creating a potential weak point although we haven't had any issues during testing. This alters the factory CV axle angles and drive line geometry. Road racers argue it could cause some adverse effects on the handling characteristics and component behavior. This makes sense so we normally advise against going this route unless you absolutely must.