Jordanlogo Posted April 23, 2021 Share Posted April 23, 2021 Just changed my alt and now upon start up there’s a loud squeal then all of a sudden it goes away. Any way to fix this? Link to comment Share on other sites More sharing options...
1986F150Six Posted April 23, 2021 Share Posted April 23, 2021 Does the new alternator have a new pulley? Is the belt tension correct? Is the belt new? Is it possible that the battery is not fully charged? Link to comment Share on other sites More sharing options...
Gary Lewis Posted April 23, 2021 Share Posted April 23, 2021 Does the new alternator have a new pulley? Is the belt tension correct? Is the belt new? Is it possible that the battery is not fully charged? Yes, I second David's questions. And, is the alternator just a replacement 1G? Hooked up exactly the same? And the same regulator? I ask because your symptoms are normal with a 3G w/o the delayed start regulator. But I wouldn't expect that from a 1G as they don't put out enough at idle to slip a properly-tightened belt. Or at least I wouldn't have thought so. Link to comment Share on other sites More sharing options...
CRittaler Posted April 23, 2021 Share Posted April 23, 2021 I would suspect that the belt isn't quite tight enough, that's assuming you had a stock alternator and replaced it with a stock alternator. Link to comment Share on other sites More sharing options...
Jordanlogo Posted April 23, 2021 Author Share Posted April 23, 2021 Does the new alternator have a new pulley? Is the belt tension correct? Is the belt new? Is it possible that the battery is not fully charged? The new alternator has the old pulley. How can I check the belt tension? Should it be super tight? Link to comment Share on other sites More sharing options...
Rusty_S85 Posted April 23, 2021 Share Posted April 23, 2021 Does the new alternator have a new pulley? Is the belt tension correct? Is the belt new? Is it possible that the battery is not fully charged? The new alternator has the old pulley. How can I check the belt tension? Should it be super tight? Rule of thumb I use is you should not be able to turn the alternator pulley. If you can turn it then the belt is too loose and will slip. Link to comment Share on other sites More sharing options...
Gary Lewis Posted April 23, 2021 Share Posted April 23, 2021 Rule of thumb I use is you should not be able to turn the alternator pulley. If you can turn it then the belt is too loose and will slip. Turn it with what? Your hand? A wrench? Link to comment Share on other sites More sharing options...
Rusty_S85 Posted April 23, 2021 Share Posted April 23, 2021 Turn it with what? Your hand? A wrench? Your hand. Put your thumb on the fan blade of the alternator and try and push. If it doesnt move I then use a wrench on the nut and try to rock it and see if it tries to rock the crank itself. Typically if you cant turn it by hand its tight enough I noticed. With the 3G I am going to use the rock method with a 3/8 ratchet on the alternator pulley to tension the belt tight enough that it tries to turn the engine. Link to comment Share on other sites More sharing options...
Jordanlogo Posted April 23, 2021 Author Share Posted April 23, 2021 Turn it with what? Your hand? A wrench? http://www.garysgaragemahal.com/uploads/6/5/8/7/65879365/thinking-26_orig.jpg Your hand. Put your thumb on the fan blade of the alternator and try and push. If it doesnt move I then use a wrench on the nut and try to rock it and see if it tries to rock the crank itself. Typically if you cant turn it by hand its tight enough I noticed. With the 3G I am going to use the rock method with a 3/8 ratchet on the alternator pulley to tension the belt tight enough that it tries to turn the engine. I just don’t get how to make it any tighter. I’m pushing the alt as hard as possible and it still is kinda loose. How do you get enough leverage? Link to comment Share on other sites More sharing options...
CRittaler Posted April 23, 2021 Share Posted April 23, 2021 I just don’t get how to make it any tighter. I’m pushing the alt as hard as possible and it still is kinda loose. How do you get enough leverage? when I did mine, I pried between the alternator and the engine block, from underneath with a pry bar. I'll try and get some pictures tonight when I can work on the truck Link to comment Share on other sites More sharing options...
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