Gearbox Detents
There's a stack of info online for this. Particularly 50s kid (again) https://www.youtube.com/watch?v=bRHjnROfRxU
I bought the punch set from ebay and the detents from FCP. This isn't a hard job, but there are some tricks to doing it well, as I've learnt now doing 5 of these boxes....
In short:
Start with 5th and Reverse pins (big pins)
These used to have different pin size oil holes, now they don't. But the springs are different, and the detents need to be installed facing each other.
Move on to 2,3,4 (small) detents
Punch out the welsh plugs
remove spring
remove detent
insert sleeve (use punch to not damage the lining!)
Insert new detent
insert new spring
insert new welsh plug
I now offer Detent replacement as a service to BMW owners - $500 drop in / pickup with a 1 week turn around. This includes me supplying the detents.
While I had the box on the bench I also pressed in new front and rear seals. What a prick of a job.