Questin on standard transmission

[doverarjim]

My son has a 95 1/2 ton 305 5 speed, he let a friend drive it for a while and he was told that the throw out bearing was going out so the friend quit driving the truck. My son takes it to a guy to fix the throw out bearing and after he replaces the clutch and pressure plate along with the throw out bearing the guy tells my son that those were not the problem but the input shaft on the transmission is messed up and that is what is wrong with the truck? Could this be true? It has been a very long time since I messed with a manual trans but I do not ever remember a input shaft going bad but when one got broke because of 8000 rpm launches. What could have caused this? Any help would be great! Thanks in advance.

[GM-Tech]

Sure, the input shaft could be damaged by the throwout bearing. Seen it many times. It just wears a groove in the shaft and causes binding of the bearing.

 

Actually, that should have said the input shaft HOUSING up there, not the input shaft itself. The housing is the part that the bearing rides on. The actual input shaft passes through that. The throw out bearing doesn't touch the input shaft itself.

 

The only part of the input shaft that I've ever seen damaged is the stub at the end that rides in the bearing in the crankshaft. The only result of this I've seen is a noise.

 

So what exactly is damaged and in what way?