MG Gearbox Tech Day
by Barney Gaylord
’Twas a cool day, but a warm tech session in the heated garage.
Several interrested (and interresting) folks showed up for this session, a few carrying gearboxes of their own due for inspection.. One broken MGA gearbox in the pictures below was disassembled and reassembled in new housing. In the process we had a good question and answer session with a lot of finger poking at the internal parts. It was clearly explained how the gearbox oil pump works, and the many points of the lubrication system, and the reason why you CAN tow an MG without disconnecting the driveshaft. The operation of syncronizers was also covered along with techniques for R&R of the parts (and a few well illustrated things NOT to do). And there was also the installation of steel Helicoils in the holes for the starter mount bolts.
Two more MGA gearboxes of slightly different models were offered up for inspection, one already rebuilt like new, and one seriously worn and abused unit for comparison. The picture here shows a broken tooth on 3rd gear. We then opened an early MGB 3-synchro gearbox for internal inspection (without much disassembly) and found it to be in surprisingly good condition, only in need of cleaning and fresh seals. and having one very minor gear tooth chip that could be safely ignored.
Two more gearboxes were offered upon the alter, both being later 4-syncro MGB units. One had a sticky reverse lockout plunger that would have made it terribly easy to find (and grind) reverse when downshifting from 3rd, as well as leaving the backup lights on most of the time. The other had a badly worn and probably non functional 3rd gear syncronizer ring as well as a significantly chipped reverse gear, but no marks on the mating tooth ring of the laygear (very strange). Unfortunately the Midget gearbox and the two MGB overdrive gearboxes that were supposed to show up didn’t, even though one of the owners did (shame on you, Cowboy).
With a little time left and a few people still hanging around, some attention was turned back to an open engine left over from the last engine tech session. Just some curious poking around here with some good Q&A time, followed up by a brief demonstration of a Crane cam timing tool kit.
Find pictures on the web at: