Skreaching noise when trimming

[tmh]

I've noticed I hear I loud screaching noise when cruising along and changing the trim setting. The noise sounds kinda like a belt noise, but not knowing the mechanics of how the trim works, I really don't know. I've noticed the noise much more recently, since switching to a 17p SS prop from a 19p aluminum. I can't see how the prop would matter, but I mention it just because I hear it much more now than before I switched - likely just coincedence I think.

It's a 1985 mercruiser 305 with alpha one.

Any ideas what it might be? Very high pitched skreech, only while trimming.

 

[tmh]

Re: Skreaching noise when trimming

Just a "bump" because the board is so active past few days.

 

[loppster]

Re: Skreaching noise when trimming

Chances are that it is your belts. My Merc was doing the same thing while under way, I was trimming and the belts would start "screeching". I figured it was because it was putting a little more load on the engine to move the outdrive while under way, thus the belts slipping. I changed my belts this last week and now the "screeching" has disappeared.

 

[tmh]

Re: Skreaching noise when trimming

OK, that's what it SOUNDS like, I just couldn't figure out how trimming out would make the belts screech. But, sounds like it can due to increased load or whatever?

Thanks

 

[Don S]

Re: Skreaching noise when trimming

The trim pump uses a lot of amperage, and the alternator will try to increase output. If the belt is loose, it will squeel. Are your pulleys all rusty?

 

[tmh]

Re: Skreaching noise when trimming

The trim pump uses a lot of amperage, and the alternator will try to increase output. If the belt is loose, it will squeel. Are your pulleys all rusty?

I'll have a look at their condition this weekend. From the description, i am sure this is what the problem is. Would it be an adjustment of the tension or belt replacement? Either way, is it a reasonably easy DIY job?

I'll do a "belt" search here and see what info i find! I'm sure it's been discussed before.

Thanks again.

 

[f_inscreenname]

Re: Skreaching noise when trimming

Check your belt to make sure it is tight enough. If so get some "belt dressing" from your local auto parts store and give it a try. Should work for a little while and tell you if you are going in the right direction.

 

[Maclin]

Re: Skreaching noise when trimming

This exact scenario happened to me. I had a constant squealing that sounded exactly like a failing power steering pump. The pump oil level was fine so I figured I would have to replace the pump...but the steering was ok. It got worse when I ran the trim motor, it did not change much when I turned the steering wheel which is what I would expect if it was the power steering pump. It was the alternator belt slipping that was making the noise, a slipping belt must sound way different in a boat than a car! New belts fixed the problem.

 

[tmh]

Re: Skreaching noise when trimming

Yep, it was the belts needed tightening. Fixed! Great help, guys.

Thanks.