Prop Shaft Alignment Yearly Maintenance Item

[walb0244]

I started this process. Was worried about not being able to get it done before leaving on vacation so I'm gonna put it off till I get back. I was working on doing fluid changes and such and noticed this forum so thought I would look at this. Well when I looked at the bolts holding the two shafts together they were loose and you could spin them by hand. I know someone else on here had the same problem and replaced the bolts. I took a picture of the bolts so everyone could see. The lock nuts could be spun off by hand so they weren't working that well anymore either. The threads on the bolts were pretty much shot from being loose. Also, my bolts were 2 1/4" long for anyone that wants to know if they replace them.

[squeeg333]

Found the exact same issue when I first went to do an engine alignment. Those flat threads are the ones inside the coupling, and don't come into contact with the locknuts, but it is good practice to replace a bolt showing any signs of damage. I replaced both the bolts and locknuts with new this year, and am glad I did. Just good piece of mind. I check them for tightness once in a while, just to make sure they don't vibrate loose.

One piece of advice I'd give when putting new bolts and nuts in is use some anti-sieze on the threads, or some other form of thread lubricant. As they are stainless bolts and nuts (assuming that's what you replace them with), they can gall. And once Stainless galls, it's game over. I had to cut one of the bolts out of my boat. Not fun.

[walb0244]

Yeah I put Some on the bolts so they wouldn't seize up. I was worried that the flats in the threads was from where the bolts were loose. Also since the lock nuts were shot I went ahead and replaced it all. Now just actually need to do the alignment part.

[kaneboats]

FYI: If anyone decides to do a shaft replacement you can order a replacement drive shaft from Elbert's. It works great. It also makes future changes much easier because of the A.R.E. system. However, you should know the coupler is slightly different than the stock one and requires shorter bolts. All the info you need can be found on his site:

http://www.elberts.com/system.htm

[mk_deuce]

Im a little lost. I loosened all 4 bolts and took measurements at 3,6,9, & 12 o'clock all while trying to hold the couplers together. My gap was uniformly way bigger than .005 at all points. In fact it was big enough to fit the biggest feeler through. Should I be checking the gap with the bolts tightened to get more accurate numbers? Im supposed to be running the feeler gauage through the gap between couplers correct?

[Boonejeepin]

I am having the same issue. I can't close the gap. Does it just need to be a .002 difference or less at the reference points (could be .012 and .014)?

[yotaismygame]

I'm having the same problem as the two guys above me. What's the solution for this?

[kaneboats]

Maybe Doc can give us a new tutorial on how to check this?????

[DOCDRS]

1. Loosen the 4 9/16 bolts a few turns so you can free the driveshaft output flange from the prop shaft flange.......if the two flanges are stuck together just bump the engine over

2. Now pull the prop shaft flange into the vdrive out put flange with your left hand check the gap at 12 then at 6 then at 3 o'clock . To do 9 you will have pull with left and measure with right. Yes it may require a contortion move. If you are not aligned one of these will be 0 and the others will be open. If all are open then go have a bowl of wheaties or grow a pair and pull harder on the prop shaft.


When the bolts are tight there will be no gap between the coupler plates even when misaligned . When you loosen the bolts sometimes there is no gap until you free the two halves. If you are getting open points all around the coupler then you are not bringing the prop shaft half close enough to the vdrive half.

Hope this helps, let me know

[yotaismygame]

I loosened all 4 which made a gap. You're saying the two flanges should be able to completely separate? This was not happening for me. If I applied pressure with my left and measured with my right there was no changes. So it sounds like they are stuck together? I had a big gap all the way around even when applying pressure.