My 1 1/2 litre gearbox was working OK and with no oil leaks, when I then drained the oil ready for a full service on the car. I forgot about it (senior moment) for several weeks and only just today filled it back up. It has now got 2 small oil leaks from around bolts at the bottom of the Extension Box housing - one is a flange bolt and the other the bolt (item 2 on the parts drawing: Part No 37444) holding the Locking Plate for the Counter and Reverse Shafts.
It does not seem to be leaking from the main gasket between the flanges of the Gearbox housing and Extension Box, but rather up and out of the treads behind the heads of the 2 offending bolts.
Question: Should there be a separate seal/gasket for the Locking Plate (nothing is shown on the Parts List, and I can’t physically see anything there), and/or is it viable to torque up these two offending bolts (or indeed all flange bolts) to see if that stops the leaks? Alternatively I could re-drain the gearbox, remove these two bolts, put some gasket seal around the threads and pop them back in. Anyone any experience of solving this type of problem (rather than taking the Extension Box apart fully to replace the gasket - which could be done I believe with the gearbox itself still left in place)?
Has anyone sourced a supplier for these 1 1/2 litre gearbox gaskets (Parts: 39773 front; 37555 Extension box; and 36542 for the rear end cover).