Squeek from rear of truck

[AJ168]

My 05 Sport Trac has been making this somewhat intermittent squeak coming from somewhere in the back of the truck. I would assume it is from somewhere in the driveline, as it only does it once everything is warmed up and I am applying some throttle. The squeak increases in frequency with vehicle speed, independent of engine rpm. As soon as i let off the throttle, the squeak goes away. I had initially thought it would be the u-joints, which I replaced, and still didn't solve the problem. I'm not sure where else to look. I can never seem to do it when I have the truck up in the air, so I can never pinpoint exactly where it's coming from.

Thanks.

 

[SoNic67]

From the leafs?

 

[AJ168]

No it's not a suspension squeak, it's directly related to vehicle speed at a constant interval. As I speed up, the squeak increases in frequency proportional to speed.

 

[SoNic67]

If it's related to power applied, it might be something that shifts under load and gets in a position that rubs against a rotating part. From what you say is almost like it is when the truck loads the back due to acceleration.
It might be then the bearings. I would drive it like that, at some point it will get worse enough that you will be able to pinpoint