View Full Version : Shaft alignment- JimN?

07-11-2005, 09:36 PM
Just helped a friend out with their 94' Tige. They were having vibrations at lower to mid speed that was pretty fierce. The boat has about 45 hours on a new engine (350) It looked like to me the shaft wasn't completely lined up with the journal. They called Hern Marine and they said you need to use a laser alignment tool. Can one do this on their own without the said tool? You'd think if you could get a good line of sight on it and use some sort of a feeler gauge in the journal that you could get it dialed in. JimN, any ideas?

07-12-2005, 10:11 AM
They are full of it to their ears. I don't know the details on how to do it but it is done with feeler guages between the flange of the driveshaft and the flange on the transmission. You also want to be sure the shaft or prop aren't causing the vibration.

07-12-2005, 10:15 AM
Thanks George. I am pretty certain the prop is good, I let them borrow my freshly resurfaced 4 blade OJ. Hard telling on the shaft without the proper equipment. What's the gap tolerance suppose to be between the shaft coupler?

east tx skier
07-12-2005, 10:17 AM
While you're at it, go ahead and check the shaft packing. This ended up being the source of some pretty good vibration on my brother-in-law's boat last year.

07-12-2005, 12:09 PM
Sorry you'll need JimN to give that answer.

07-12-2005, 12:40 PM
The out of alignment tolerance is .003". It is not hard to check, it is not hard to align, it just takes patience. So, you get your trusty feeler gauges, remove the flange bolts so that they can be slightly separated. Place your .003" feeler gauge or smaller, between the flange and coupler and push together. Remove the gauge and see if it is tight or loose at other spots on the flange. Adjust the motor accordingly. Re-check your tolerances.