squeak from left rear wheel

[gt1009]

I recently changed the oil in my truck, and after that it seems that there has been a squeal coming from what sounds like the left rear of the truck when I take my foot off the gas. It doesn't happen every time, and it seems to come and go randomly. I am also leaking something from my engine, but I can't tell what yet. Can someone please give me some guiding questions or advice so I can figure out how to go about fixing this.
Thanks,

 

[86M10086.2L]

In my expierence those noises tend to be either a failing/dry u-joint or a hanging or worn out brake shoe. Sometimes excessive brake dust can do the same. I would start there.

 

[CARNAC]

Absolutely concur on that--u joint, dust, then shoe issue.

 

[DriverSideImpact1008]

What kind of a squeak is it? Like speed, loudness,that kind of thing.

 

[gt1009]

Ok the squeak is gone, I rotated the tires and it went away, but now I have vibrations from 25-45 mph, I'm thinking its a wheel out of balance? If you care to give me some advice it would be most appreciatec, I'm only 17 and I'm just learning each problem's fix as it comes up.
Thanks,

 

[86M10086.2L]

It could be a out of balance tire, it could also be a bad tire. I've had new as well as old tires shift a belt and give a heck of a vibration. How bad is the vibration? Give alll your tires a good look over. If you can spin them while they are still on the truck you will be able to see if a belt has shifted. the tread will be wavy. Of course any other obvious stuff, exposed belts, missing tread, choppy tread. Outside of that you could bring them to a tire shop and have them balanced again. Again no expert knowledge here but at least a place to start. Also visually inspect the driveshafts. Make sure there's no obvious damage to them as they can give a good vibration as well.