Mabey i'm thiking just a little too simple but right now my truck is making a squeaking sound because i have a bad universal joint (getting it changed the week) might not be your problem but its worth a look

Cold man

 

Mine didn't squeak when it went out...but I guess that doesn't mean much. If its in really bad shape, the belt would be slipping off of the alternator and you might be able to see the spring on the inside of the tensioner...when they wear out the cover plate starts backing away from the flush side of the motor.

Also on the tranny idea...I have an auto tranny and have hauled some pretty heavy loads and it has never made any noise.

I guess the only way to figure out what this might be is to try your darndest to locate the origin of the squeak.

 

I'm not sure about this... does our PSD have a fan clutch? If so, that could explain the potential for squealing under loaded conditions. I've had the fan clutch create similar "an and off" squealing tendencies on my gassers, but my experience there is that the squealing tends to go away under load and returns at low speeds and idle. Just a guess.

 

The sound from the clutch fan is more of a low groan. This is a high pitched squeal, My experience with it is only in hot temperatures and after a long grade. Once over the grade and I put the tranny back in OD and then the sound would go away unless I would kick down to pass.

 

My carrier bearing went out and it made a high pitched squeeling noise under load. I thought it was the turbo, it sure sounded like it was coming from the engine compartment. Its hard to nail this stuff down sometimes unless you can duplicate the problem and have someone ride around with you that can move around the truck and try to hear exactly where its coming from.

 

I hadn't thought of the tensioner pulley bearing, I will have to check that out. MN350 did you just replace the bearing or the entire assembly? Do you have a part number for the bearing. At this point, mine could stand to be replaced anyway and this would be a good reason.

 

I kinda have the same "symptom", uhhh, I think- the tensioner pulley bounces up and down in rythm with the engine. I don't know if maybe the fan is "out of round" and causing this, or is the tensioner just shot. IF it is, anyone know of a way to test it. It still takes a good bit of elbow grease to move it with a 1/2" breaker bar.

 

Sorry, I wish that I could be more help, I had it done at the dealership just after I bought the truck 4 years ago.

Scott Johnson
2001 F-350, 6637, Remote start, Rancho RSX's

 

Forgot to mention that it does it when the truck sits for a while (24 hours) and its hot...its like the belt gets real tight and after it runs for about 5 minutes it goes away...it doesnt do it at idle, just when you give it some fuel....