check my trans for ? when diff blows

No it doesn't apply to a 4 speed. It's only a problem with the automatics. It will sometimes roll the over running clutch tangs over then when you lean on it again in 1st the over running clutch won't hold and it overspeeds the front drum. If it's a 727 it will most likely explode due to spinning at 3X the engine RPM. 904's don't usually explode the drum but will still hurt the over running clutch.