




RD4012
Restore and enhance your BMW limited slip differential with RacingDiffs upgrade kits designed specifically for the 188mm medium-case LSD. These differentials were commonly found in most 6-cylinder BMW models up to 1999.
BMW 188mm medium-case LSDs were used in the following models:
If you are purchasing a pack that includes the reinforced billet steel cap, please leave a note with your differential gear ratio.
There are two different billet caps depending on the ratio: 2.64–3.07 or 3.15–4.45.
Every kit is Plug & Play — no machining or modifications required.
Replacing worn clutch plates restores original LSD performance. For increased lock and durability in spirited street or track driving, Stage 1 and Stage 2 packs are recommended.
For competition use and maximum performance, choose Stage 3 or Stage 4.
Stage 4 pack is covered by our LIFETIME WARRANTY.
Service Pack
Street Pack – Stage 1
Track Pack – Stage 2
Race Pack – Stage 3
Max Performance Pack – Stage 4
All RacingDiffs LSD upgrade kits are Plug & Play. No modifications are required.
Installation tutorials are available on our official YouTube channel .
For a complete rebuild, we recommend adding a bearing & oil seal set .
33141210626 / 33-14-12-10-626
33141203797 / 33-14-12-03-797
33141203795 / 33-14-12-03-795
33141203794 / 33-14-12-03-794
33141206909 / 33-14-12-06-909
33141204367 / 33-14-12-04-367
33141206919 / 33-14-12-06-919