Having some trouble aligning the transmission input shaft. I have checked the crankshaft flange at three different radius and it's flat. Removed any burrs around the bolt holes. The flange feels nice and flat. I have a set of new locating pins which I place in the flange, then install the input shaft over that, tightening it down. Then with a dial gauge I check for run out. I can easily make it real bad +0.020", but have trouble getting it to under 0.010". I had the input shaft in a colette on the lathe and it's flange is square. So.... I tried aligning the transmission shaft without the pins and I can get it dead nuts on. But, one pin will drop in place and the other is snug. If I push that snug pin in with a hammer, now the transmission shaft is out of whack again. My question is how to repair this. Is it a pin problem or a hole problem. Should I polish a pin or a hole, both? I get the same results after turning the shaft 180. Ideas? Thanks Mike
You don't say if the crank has been reground. If that is the case it could have been ground off center. This would have the locator pin hole off and you will have run out. I have corrected this problem and would be happy to talk you through it. PM your phone number and I can talk you through it if you like.
Under .010" run our is not good. .000" is really good and maybe up to .0015" or so is OK
To much to write up without having all the questions answered
Here is a solution.
Pm me for more info. Dan
The crank has not been reground. This is an old crank from an old car that developed a knock. One of the connecting rods was missing a lot of babbit, and that has been corrected. We checked the journals and they are all good.
Have you tried rotating the shaft 180 degrees There are two possible positions the shaft can be installed. It's possible that it will fit better when rotated. If so, mark things so that it can be installed in that position.