I hope this is the right place to ask ! I have a 1972 Rover P6 that has a LT77 five speed box fitted .

Does this have a filter inside one of the drain plugs ? Do some have it and others don't .... When my car was serviced last year I bought a filter ( like a plastic tube with tiny holes ) . However , when my mechanic drained the gearbox and re-filled it he said it didn't have a filter ! Confused

 

Not sure but i guess it will depend on what version the box is, AFAIK they were used in Jags and possibly the SD1 as well as the RRC.
I wouldnt expect the RWD versions to have a filter.