I have Cat diesels on my 2000 SeaRay...

[SeaMax]

I have Cat diesels on my 2000 SeaRay 410. Engines have about 1100 hours. I think the belts are original, or at minimum have been changed once - not since I have owned the boat - had about 800 hours when I acquired it. My mechanic says the belts look good - and when I looked at them i agreed, no tearing, fraying, cracking etc. I am wondering if there is a time (hours) to change regardless of how they look. There is probably something in the manual but I find experience is a better indicator so I would appreciate any comments other than “just change them”.

[fwebster]

This is one of those maintenance items that you never want to have to do as an emergency while underway somewhere in a sloppy sea. It is about a 2.5 hour job just removing the belt guards on a 3116/3126, so my view is that $90 worth of belts in the off season is very cheap insurance.

I only use caterpillar belts because they are superior to parts store belts. I change mine every 250 hour and once removed, you can feel the difference between a new belt and one with 250 hours on it.

[SeaMax]

Looking at changing the belts, there is a triangular plate that has a cable through it and the plate must be removed. There is a tag on the plate from Glendinning Marine that says alignment is critical and an alignment tool must be used. My best guess is this cable is for the tach. Not sure where I will find an alignment tool, will talk to Glendinning but wondering if anyone else has run into this and if so, how difficult is the alignment process. Any other information on this subject would be appreciated.

[fwebster]

I change my accessory belts every 500 hours and have never used an alignment tool. Alignment it was since the shaft has a very straightforward shape that is easy to align by sight. At 1000+ hours, no matter how your belts look, they are rubber, are dried out and should be replaced.

At 1000 hours, if you have never removed the Glendenning synchronizer tach drive and lubricated it, you will very likely find a lot of wear on the end of the short cable that mates with the crankshaft damper. It is an inexpensive part (from Glendenning -$75) and replacing it on your schedule is far better than losing the synchronizer on a long trip.

[SeaMax]

I agree and the belts are going to get changed. Unfortunately my marina mechanic is not a diesel guy, nor is there anyone close. When he saw the big "warning" sign, he stopped - which I guess is good. I will probably try to get an alignment tool just to make him comfortable with the job. I downloaded the manual from Glendinnning site at it looks pretty straight forward. Plus you can run the engine and look for any wobbling in the connector cable as a double check. Do you have a recommendation for lubricating the short cable connection if its not worn too bad?