I've got a 2001 f-350 V-10 that makes a squealing noise going up a steep hill until it shifts into a higher gear. I must also say that it only happens when pulling my trailer of 7,000 lbs. It sounds like a pulley or belt, but I,m a new owner and can't be sure. Any input would be helpfull.

 

I guess I would check the belt and or belt tension first to make sure that that is OK.....

 

Hi seattlem45. Welcome to FTE!

As mentioned, check your serpentine belt. If it looks frayed, glazed, cracked, worn, burnt or just old and tired, replace it.

 

First, WELCOME to FTE! Definitely check the belt and tensioner.

My 2001 squeeled when shifting from 1st to 2nd under hard acceleration, and a "cog" belt made it go away forever.

If this is the original belt, first, it's time to replace it anyway. Second, my BRAND-NEW 2001 V10 did that 1st-to-2nd squeal the first year I had it. That stock belt sucked.

 

as stated check the belt.my 2000 excursion v10 would squeel when it shifted under hard acceleration.belt was new but it did it anyways.its actually more common than i thought because a few friends(even chevys) do the same thing

 

I've had great luck the the Goodyear Gatorback line of serpentine belts.

Goodyear® Engineered Products :: Gatorback? Poly-V Serpentine Belts With Quiet Channel Technology

 

+1. Brand new tensioner and belt and my will still make all sort of noise under a WOT shift especially running the 5 Star 93 Tune.

Time to buy a Goodyear Gatorback like I use in my other vehicles.

 

I used a Dayco "cog belt" last time, and it works quite well.

 

1. is something "overloaded" on your belt driven devices?

i.e. air conditioner, etc.

2. the tunes is a problem --- excess hp beyond what the devices can handle.