alternator - SailNet Community
 
LinkBack Thread Tools
post #1 of 8 Old 08-28-2008 Thread Starter
Member
 
nelsonsmoody's Avatar
 
Join Date: Nov 2005
Posts: 58
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 10
 
alternator

Hello all,
>>
My alternator making a screeching sound when revving up form 1000 and 1500 rpm at the initial starting of the engine and then it goes away after 3 to 5 minutes of engine running. Is the alternator going bad?
Nelson
nelsonsmoody is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 8 Old 08-28-2008
Handsome devil
 
Stillraining's Avatar
 
Join Date: Jan 2008
Location: LaConner,Washington
Posts: 3,477
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 10
     
Most likely belt tension..shouldn't be able to depress it but maybe 1/2" with moderate pressure from a couple fingers mid way between pulleys..Id start there.
Stillraining is offline  
Quote Quick Reply Share with Facebook
post #3 of 8 Old 08-28-2008
Special Delivery
 
speciald's Avatar
 
Join Date: Mar 2007
Location: live on boat
Posts: 661
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
 
Send a message via Skype™ to speciald
Sounds like a worn or loose belt. Check tension and treat belt with conditioner or replace belt.
speciald is offline  
Quote Quick Reply Share with Facebook
post #4 of 8 Old 08-28-2008
Senior Member
 
Join Date: Sep 2006
Location: Scotland
Posts: 2,364
Thanks: 0
Thanked 11 Times in 11 Posts
Rep Power: 9
 
Yes, tighten the belt a bit and I am pretty sure it will go away.
At low revs, for a given power output, the tension has to be higher than at high revs.
It tends to slip at lower revs.
Rockter is offline  
Quote Quick Reply Share with Facebook
post #5 of 8 Old 08-28-2008
Senior Member
 
chucklesR's Avatar
 
Join Date: Sep 2007
Location: Pasadena Md - Magothy side
Posts: 5,979
Thanks: 10
Thanked 31 Times in 31 Posts
Rep Power: 10
     
Or put some soapy water on it (revitalizes the rubber in the belt or some such thing).
Temporary fix tho, if tightening it up doesn't do it and the soapy water does you need a new belt.
chucklesR is offline  
Quote Quick Reply Share with Facebook
post #6 of 8 Old 08-28-2008
Senior Member
 
Join Date: Apr 2008
Location: Melbourne, Florida
Posts: 418
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 8
 
Yeah, I agree with all of the above. In addition, I'd check the belt for any glazing or cracking. If noted, replace. I'd also check for correct fit. I was told years ago by a Gates rep., IIRC, that a 'v' belt should fit into the pulleys no more than 1/16th of an inch above the groove and no more than
1/8th of an inch below to insure a proper fit.

Another source of slippage is misalignment from pulley to pulley. You can check this with a straigt edge or by eyball if you have access to align the pulleys up by line of sight.

The 1/2 inch deflection of the belt is a good test, but another way of checking if you have enough tension on the belt is to get a rag and with a good grip on the cooling fins of the alternator pulley, try to make the pulley slip in either direction. If it does, adjustment is in order. Good luck.

Bob
fullkeel7 is offline  
Quote Quick Reply Share with Facebook
post #7 of 8 Old 08-28-2008 Thread Starter
Member
 
nelsonsmoody's Avatar
 
Join Date: Nov 2005
Posts: 58
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 10
 
thank you so much for information and I try all over this weekend.
many thanks to all.
nelson
nelsonsmoody is offline  
Quote Quick Reply Share with Facebook
post #8 of 8 Old 08-29-2008
Senior Member
 
hellosailor's Avatar
 
Join Date: Apr 2006
Posts: 11,346
Thanks: 5
Thanked 129 Times in 126 Posts
Rep Power: 11
   
"Or put some soapy water on it " Ouch! Never! Never put soap on rubber, it rots the rubber and gives it a better grip for a while--but then the rotten rubber fails. Drag racers used to soap their tires to get better traction at starts.

There's never been a belt maker that recommeneded any "belt dressing" or other magic in a can, it can't solve anything that proper pulley alignment, belt tension, and a good belt can't solve without the goo.

Too much belt tension can also ruin the alternator and engine bearings, and squeaing *could* mean an alternator bearing is failing--not just the belt. Better to check the belt condition, check for correct tension, and then check pulley alignment. If it still squeals, and the squeal is coming from the alternator, pull it and check for bearing problems. If the bearings freeze you've got a bigger problem.
hellosailor is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome