View Full Version : drive shaft tolerance

06-01-2010, 11:05 PM
How much can a drive shaft be bent out of tolerance before it is unusable. My prop guy indicates the shaft is .018 to .02 inches out of shape. He says the shaft needs to be replaced. My engine guy says run it. I have not tried it on the water yet.

06-02-2010, 08:35 PM
.003" maximum. You are way over the limit. Buy a new shaft. Using the bent shaft will lead to problems with the transmission later.

06-03-2010, 12:14 AM
Just about any machine shop should be able to straighten it. Probably a lot cheaper than buying a new one. It depends somewhat on what caused to to be bent. Hitting something solid with the prop can sometimes put a spiral "twist" in the shaft that is a real bugger to straighten, and sometimes can't be done. If it's a simple "bow", no problem using just a dial indicator, some v-blocks and a press (along with good measures of common sense and patience)

06-06-2010, 06:00 PM
Could not feel the bent shaft vibrating the boat at all. I originally damaged the prop hitting something solid like a stump in the river. I replaced the prop with a new one. First time I have had a new prop. It feels really fast. When my prop guy measured the tolerance, he did not run the boat. Can you measure the tolerance correctly without running the boat?