Pulley problems help? Idle/tensioner pulley keeps whining?

1990StangGT

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Jul 1, 2002
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Ok I installed a set of mac underdrive pullies some time ago. Now my tension pulley started whining really bad, so I replaced the whole tensioner assembly. This cured the whine but not for long it started in within a couple of days of the new tensioner. When I would spray wd-40 in the bearing it would stop whining but when it dried started up agian. I replaced the idle pulley thinking it would stop it as well but it did not and I went threw about 3 different new bearings thinking it was a bad one but it whined as a put the brand new ones on. So my question is WTF? No one seems to know why it is doing it and I sure as hell am stumped on this too. Let me know if anyone has any ideas? Thanks.
 
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WD-40 is a solvent with a light oil carrier. It is more of a cleaner than a lubricant. It's lubricating abilities are short lived at best. By spraying it on the bearing of your pulley you just removed whatever lube was packed into the bearing. I would say you are gonna have to replace it again.

Not sure why the new tensioner failed so soon. Where did you purchase the replacement? I have had the best luck sticking with genuine Motorcraft replacement parts.
 
get it replaced with one from ford before it breaks. Goto modulardepot.com in the ford parts section and tell Randy you want the "retro fit" belt kit for your car. Trust me, I've broken over 5 tensioners! The one you'll receive weighs about twice as much and is STEEL! Mine has been quiet ever since and keep the belt aligned perfect, which was another issue I was having. Also tap the crank pulley with a hammer lightely to make sure its situated on there good. And retorque the bolt. Good luck! Its not fun having those damn things break. I swear I set the world record for belt/tensioner changes. At just over 5 minutes. !!
 
Turbo92PGT said:
get it replaced with one from ford before it breaks. Goto modulardepot.com in the ford parts section and tell Randy you want the "retro fit" belt kit for your car. Trust me, I've broken over 5 tensioners! The one you'll receive weighs about twice as much and is STEEL! Mine has been quiet ever since and keep the belt aligned perfect, which was another issue I was having. Also tap the crank pulley with a hammer lightely to make sure its situated on there good. And retorque the bolt. Good luck! Its not fun having those damn things break. I swear I set the world record for belt/tensioner changes. At just over 5 minutes. !!


Andy, thanks for the plug. that kit fits 1999 back to @1993 Modulars btw. one other thing, dont use solvents or high-pressure type washes on the engines as this to can get into the so-called sealed bearings of the idlers and tensioners pulleys and "wash-out" the grease they come packed wth, thus leading to noise and early replacement.
 
Well I went to the modular depot and all they have are cobra pulleys. I would go back to autozone or any other store but none of thier pulleys seem to cure it trust me I have tried. So where can I get a high quality one at?
 
1990StangGT said:
So should I just order the new piece or spray some silicone lube in the bearing? And if so should I take it off to do this?
The pullies are not expensive but I used the silicone on mine because I just replaced it about 2 months ago and it started squealing again. I figured it must just have dried out or didn't come with enough lube. I wasn't going to replace it AGAIN after only 2 months. This was the Motorcraft pulley from the dealer.
 
1990StangGT said:
Well I went to the modular depot and all they have are cobra pulleys. I would go back to autozone or any other store but none of thier pulleys seem to cure it trust me I have tried. So where can I get a high quality one at?

Actually Randy is the Performance Parts Manager for Liberty Ford in MD. Go to the Parts forum at Modular Depot and post there telling him what you are looking for. With the holidays they probably won't be open again until Tuesday.

http://www.modulardepot.com/forums/forumdisplay.php?s=&forumid=21
 
Something I've always wondered is if the U/D setup puts extra tension on the pullies. I have replaced 1 tensioner and 1 idler pulley so far. Every time I change my oil or get under the car I notice an oily residue coming out of the bottom of the tensioner (was on the old one too). I'm curious to see where the tensioner is positioned with factory pullies compared to with U/D on. It would make sense if the belt has more tension on it to cause the idler to wear prematurely and smoke the tensioner. I know that in theory an automatic tensioner should have the same tension on the belt, but what if it's designed to only be stretched so far and all the U/D kits are stretching it too far? :shrug:
 
1990StangGT said:
What kind did you use? I took them off and spray some white lithium grease in the bearings but this only worked for about 20 minutes.
Same stuff...maybe you got a bad pulley.

I have replaced both the idler and tensioner pullies but have removed my U/D pullies. I just had too many issues with the U/D's from alternator and battery problems to the issues you have with the squeaking idler/tensioner.
 
1990StangGT said:
What kind did you use? I took them off and spray some white lithium grease in the bearings but this only worked for about 20 minutes.

There really is no way to revive a pully with a spray lubricant. The bearings are packed and sealed when they are made. Once they start going bad the only cure is replacement. You will have much better luck with Motorcraft pulleys than anything you will get from the corner auto parts store. I can't count how many threads I have read that have shown this to be the case. You may save a few pennies up front but, in the end you pay more since you wind up replacing them more often.

I recently replace mine after 57K when they began making noises.

Old Parts
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New Parts Installed including a fresh Goodyear Gatorback belt
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