66 c10 250 i6. did have an old muncie 318 tranny. swapped it out for a saginaw 3 speed. after swap, throw-out bearing went bad so i put in a new clutch kit. now the new throw-out bearing appears to be sticking on the input shaft of the tranny. has sort of a pop sound when you first start to push the clutch pedal in. also the throw-out bearing is riding against the face of the pressure plate no seperation so t-o bearing is spinning all the time. could i possibly have the wrong t-o bearing i have heard there were two different types and that i could need the shorter one. any thoughts?
The wrong throw out bearing could be a possibility. There are two styles of diaphragm pressure plates, those with low profile spring fingers (which use the tall T/O bearing) and those with high profile fingers (which use the short T/O bearing). Theoretically if you have the high profile PP and the tall bearing, it could rub all the time and be hard to release, due to interference fit. I’ve never tried this so I don’t know if the assembly will actually fit together in this configuration. I’d also be concerned about the smoothness of the pilot collar/bearing retainer the T/O bearing is riding on. In used transmissions this is often overlooked, but if it is scored or has ridges, they will interfere with smooth operation. Also, was the T/O bearing packed with grease before installation? There’s a small cavity on the I.D. of the bearing for a small amount of grease to be placed. This ensures smooth sliding on the retainer collar. Too little and clutch action can be rough or notchy, too much and it slings out and gets on the clutch. If the pilot bearing in the back of the crank wasn’t replaced, or doesn’t have enough of the right kind of lubricant, it can also create hard to diagnose problems. If there is too much wear on the pilot shaft or bearing, the assembly can squeal during shifting. If it’s too tight due to corrosion, crud, or uneven wear on either component or both, there will also be problems during gear changes since the transmission speed won’t neutralize when declutched. Another consideration is the fork, fork ball, and or linkage. If the T/O bearing in the new setup is different from the one that came out, it may be causing the linkage/fork to be rubbing on areas that were previously not used. After 40+ years of wear there can be grooves worn into components that don’t work smoothly if asked to operate in a different range of motion. One last thought is a cheap import throw out bearing that is not within spec. If everything else is perfect, the bearing itself could be too tight on the inside diameter and hanging up on the retainer collar. I’ve found offshore brake drums that were dimensionally off by ½” for the same application, so bad parts do show up in the supply line.
