Engine and Transmission Tech

This is the second defense of the orphan T50 transmission, albeit without a "blonde" posing... I've got three, one (3.4 ratio) in my 64 B with a Chevy 2.8 V6; a second on the shelf, also 3.4 ratio; and the third, 3.1, has been sitting on my workbench for ten years, partially disassembled after I lent it to a friend -- that story may come sometime later. It's origin is unknown but after disassembly, there is evidence that it had been previously messed with. The front main shaft bearing race was beaten in with a punch which cracked the sides of the race. The rear countershaft bearing was not fully seated and thus was partly chewed by first gear. However, all the gears and other bearings look good, the inside of the case was fairly clean and the magnet had a nice crop of fuzz but no metal bits attached to it.

I'd like to start out with a few questions:

1. Just what seems to be the weak link with this gear box? It looks like a good design to me, I like the shift pattern because it makes sense to have R and 1st on the left side of a double H pattern. It's compact and light too. Of course, Jim Blackwood makes these points in "Blondie" but is seems he's had a change of heart too.
2. Does anyone know a source of "loose" roller bearings? I've found some caged bearings the proper size but of course they have fewer rollers and therefore may not have enough load capacity.
3. Has anyone rebuilt the T50 and just been too shy to post?

Hope to meet some of you at Indy in June.

The T-50 is a decent transmission, and quite a bit stronger than the stock MGB unit but not nearly as strong as the T5 and not as versatile. It's harder to shift also. But within those limitations it does have some unique advantages, mostly as you stated. The "weak link" would be twofold, case strength, and the shifter. In an MGB, at about the 300hp level you can crack the case (done that). As for the shifter, if everything is perfect it will still shift significantly harder than the average T5. The reverse lockout frequently has problems and engaging reverse can be either too difficult or too easy. As for the pattern, there is nothing wrong with that if the reverse lockout is working correctly, but if it is not it compounds the shifting problems.

I'm not sure what clearances are allowable in the needle bearings or where to find them, but it may be acceptable to run them looser than you think. You might try checking with someone who rebuilds manual transmissions though, bearing houses and suppliers like McMaster-Carr.

JB