My BW Model 12 saga continues:
It has the later XJ6 BW transmission.- works perfectly after 15km of driving (once hot).
Before that, its awful - when cold, takes off in top gear (or second) no electric kickdown, no vaccum gear drop, no first gear.
Governor checked, linkage fixed, vacuum OK.
Consensus seems to be that seals may be hard, and everything expands when hot (then OK).
I think I am looking down the barrel at $6-$8k rebuild. Or putting up with it (latter!!).
It is so powerful that it is happy to drive well even before everything works.
Other option is to find BW12 reconditioned gearbox if anyone has one!!

 

Michael
You might be better off throwing this question at the XJ6 part of this forum.
Cheers