This is normally done with the engine gearbox out of the car as i did last year BUT with the right tools is possible in situ.

Read how it’s done at ……. http://diary-of-mgb.blogspot.com/2011/10/that-seals-it.html
a collection of classic car tech tips, tricks, ideas and information all about performance, modifications, maintaining the MG MGB and GT from across the Internet. Also tuning, servicing, repairs and mods on my own classic car a 1975 MGB Roadster
This is normally done with the engine gearbox out of the car as i did last year BUT with the right tools is possible in situ.
Read how it’s done at ……. http://diary-of-mgb.blogspot.com/2011/10/that-seals-it.html