Well my TH350 lost 3rd gear last night, made it home in 2nd luckily cranking about 3500 at 45 it got pretty warm but it made it. I tore it apart today and found that the roller clutch was no longer in tack and the sprag was cracked into 2 pieces...... not exactly sure what happened but i think the little bearings in the roller clutch froze up for some reason and broke the sprag and then the clutches wouldnt move.....all the clutches were fine other than they were stuck on the sprag ring. So i just ordered a new sprag and drum and a outter race.... suppose to be some special hevy duty one from jegs it better be for 300 some bucks... im also going to replace the stock flywheel while i have it all apart.... but does anyone have any idea why this might have happened... i hear it is kind of common? I will post some pics as soon as i can.

 

The sprag explosion is a pretty common failure in otherwise stock 350s with shift kits and well-stacked clutch packs and such.

TCI used to have a hardened one, that was the hot trick in its day; they, or someone, should still offer such a thing.