Guys,
This is for an early (chrome) 74 B. Two years ago when I had to double clutch to down shift into second I decided that it just added character. Ditto when I started having to physically hold the shifter in third to keep it from popping out. Then first gear would pop out also, which was slightly more annoying, especially with morning coffee. Then a month ago the rear seal blew. I popped it back in and re-filled it but soon after something went suddenly very wrong and I could barely get it into 4th. At that point I decided to have a look inside.
A local LBC mechanic shop said that it is possible to remove the transmission without removing the engine. I put the car up on ramps and jack stands, and after a few evening sessions managed to get the transmission down out of the car. The trick, that I eventually figured out, was to remove the remote control housing first. I didn't even have to remove the exhaust pipe, although it was so tight that I might need to to get it back in.
I took the transmission apart following the Haynes manual and the first thing I noticed was the remains of a bearing cage loose at the bottom. The rear bearing still has its balls, but the cage blew out. Maybe this caused, or was caused by, the rear seal failure. I've never studied transmissions before, and have spent quite a few fascinating evenings moving things around figuring out how it works. My guess is that somewhere along the line the main shaft shifted back, making the control mechanism ineffective at operating the sliding hubs sufficently. I did the checks that Haynes and a document I found on MGBEXPRIENCE suggest and ordered a synchro (baulk ring?), a rear bearing, some shims, and a few other things. Putting it back together doesn't look too bad, but getting it back in the car promisses to be a chore. Someone offered a transmission jack with several dimensions of fine control, which might be a big help.
If anyone here has words of wisdom, they would be appreciated. For example, I wonder sbout the best way to clean everything before reassembly. I thought about hosing out the cast assembly to get all the grit from the corners. Should I wash the bearings in gasoline or something to make sure they are grit free?
TNX, Dave