Alternator Squeals Like a B$%!#

[bobafett]

I have mercruiser 140 HP. The alt. squeals intermittently particularly when throttle is applied, but when it does it is loud! The belt is alread tighened to the max in the alt. slot. Sometimes when I can pull alt back toward fuel tank while someone is on the throttle it will go away, but then after the next idle it will start again when throttle is applied. What should I do, Try to beng the alternator on the mounting bracket? Has the belt been stretched to much?<br />Also please read my other post on full throttle cut off, I still need advice on it too. Thanks in advance

 

[Haut Medoc]

Re: Alternator Squeals Like a B$%!#

Is the belt glazed from being loose? Did you try a new belt?

 

[Don S]

Re: Alternator Squeals Like a B$%!#

The belt didn't stretch, but if the pulleys are rusty, it's probably a lot thinner.<br />Or you just need a size shorter belt.

 

[bobafett]

Re: Alternator Squeals Like a B$%!#

The belt isn't that old- I had a boat mechic put it on because i don't have an engine lift. The belt was put on 3 years ago but the squealing started last year. It doesn't look glazed but pulley on the alt is a little rusty. When you look at the belt from the side the crank and water pump align good, but the alt pulley appears to push a little toward the bow. Could it be the bearing in the alt going bad? Is there a dressing a can use on the current belt without taking it in to go smaller?<br />Thanks

 

[vipzach]

Re: Alternator Squeals Like a B$%!#

Originally posted by bobafett:<br /> It doesn't look glazed but pulley on the alt is a little rusty. <br />Thanks

I would get some sand paper and get that rust off there first. Some of the crazier guys will do this with the motor running, If you do that please be careful. I would just loosen it up and pull the belt off, then get the rust off the pulley.

 

[cneste]

Re: Alternator Squeals Like a B$%!#

Sounds like the belt might of been too tight in the past causing the bearing to wear out prematurely. I have found a cheap place for rebuilt marine alternators. I paid $65 with shipping and no core for a delco alternator for a 1988 4.3L application. Check them out.<br /> http://www.reliabilt.com/bottom.html <br /><br /> http://www.reliabilt.com/7152.html <br /><br />1300-6A Stirling Road Dania, Florida 33004 <br />Phone - (954) 921-7833 Fax (954)925-0411 Toll Free 1-888-921-7833

 

[bobafett]

Re: Alternator Squeals Like a B$%!#

Thanks for the link! I will take a look.

 

[Boatist]

Re: Alternator Squeals Like a B$%!#

Belts do not streach but if you have rusty pulleys they will wear on the sides and instead riding at the top of the pulleys will ride at the bottom of the pulleys. This will make belt seem too long. Also if riding at the bottom will slip even when tight. <br />If the bearings are bad they are very cheap.<br /><br />Go get two belts the correct size. Compare the width if new belt is wider then replace belt and at same time slide the spare in place then tie up out of the way. This way if it fails on the water you can replace and get alternator and WATER PUMP back on line.

 

[bobafett]

Re: Alternator Squeals Like a B$%!#

Can I switch out the belt in the Merc 140 without having to have an engine hoist? Is there a specific sequence?

 

[Watercanuck]

Re: Alternator Squeals Like a B$%!#

A good way to test if it is the belt is to pour a little dish soap on the belt. If it stops then its the belt, if not, then its the alternator.

 

[hoot]

Re: Alternator Squeals Like a B$%!#

look closely at your front motor mount. see if there is a spacer on the right side as you are looking at the motor. i would still consider blocking under the motor with something (2X4?) to prevent movement.

 

[bobafett]

Re: Alternator Squeals Like a B$%!#

Thanks. I will see if the soap stops the squeal. If the belt still squeals I will attempt motor mount separation. Not sure about where the "spacer" is but will use blocks to keep the motor from dropping. Will let you know the results.

 

[MrBill]

Re: Alternator Squeals Like a B$%!#

Use the proper stuff...get som=e belt dressing (comes in a spray can) at the local auto parts supplier. If that doesn't do it, a mechnais fix will be necessary. Soap might stop a squeal foir a short time, but belt dressing removes glaze and makes the belt tacky.

 

[jeff13601]

Re: Alternator Squeals Like a B$%!#

When you take out the spacer on the port side of the front mount the engine is not going to drop. You need to turn the pulley by hand and see if the alt is turning hard. If it is not then sand the pulleys as suggested and put on the proper belt.

 

[Boatist]

Re: Alternator Squeals Like a B$%!#

You do not need a hoist. You can use many things to support front of the motor. A 2x4 and a small block of wood. Belt dressing is not going to fix a worn belt running near the bottom of the pulley. All it will do is stop it from making noise then whey you are 20 miles out to sea the alternator and water pump will stop turning and you will over heat and be dead in the water. Fix right buy a new belt you need a spare anyway.