CC25 8.1 Volvo Penta Whine

[NJfishing]

My 1999 CC25 8.1 Vovlo Penta with jackshaft just started to make a whinning noise. Not noticable at idle RPMS but at 2000 RPM and above reguardless of in neutral or underway.....It's not a real loud whine but is noticable, at least to my ear....

Never had a problem with the drive just changed the gear oil every season.
Changed the bellows cover about 2 years ago. Boat seems to run fine and gets up to WOT RPM no problem.

I'm thinking it could be the u joint shaft inside the bellows, maybe jackshaft or maybe the drive itself. Any other ideas.... I'd hate to have to pull the boat to find out since it's coming up on prime Striper season here in NJ.

Any thoughts or things to look at would be appreciated.

Thanks guys...

[Golden Dog]

I know nothing about jackshafts and the related components, but, you mentioned the whine is present when the boat is in neutral above 2000rpms anyways...so I don't u/s why you suspect the drive train? Could be as simple as a tired/loose belt which is probably the place to look first.

[outriggers]

It's pretty easy to pull the outdrive and you'll know if it's coming from there. Also you can unbolt the driveshaft very easy to test for the bearings in the rear. You would have to do a little work to replace the front bearings without pulling the engine but it can be done. I have just installed a 8.1 in the 25 I bought and it's tight at the rear of the engine. You should be able to unbolt the driveshat pretty easy though. Be sure to mark the position of the shaft to the engine jackshaft adaptor so that you won't have to rebalance the shaft. Same applies for the rear.

[otcutshine]

whine

Remove wife from closet, whine should stop!
Seriously, check stupid things first. My 28 had a whine that turned out to be deck cooler drain hose rubbing drive shaft and knocking weights off shaft. Other time whine was gimbal bearing ready to come loose. Determine if whine is in gear or out, port or starboard. Good Luck!

[NJfishing]

Thanks

Thanks for the replies guys.... Going down to check her later on in the week.

PS.... I'ts a single engine and whine is present in and out of gear...

[Flying Colors]

we have the same problem after we repaced the outdrive, (becouse the old one got riped off after we hit the rock jettie in morhead city) and it seems to be cooming from the outdrive.

[lowprofile]

I had a whine or more of a grawl from my 28 and it was the intermediate housing bearings. The had gotten water in the from a previous failure of the bellows before I bought the boat.
I rebuilt both of the intermediates and now the noise is gone.