Odd noise

[Esox_Magnum]

01 GMC 4x4 5.3,105K, best way to decribe the noise is it comes from under the truck and changes pitch with increased speed but nothing in nuetral. Sounds similar to a playing card in a bike wheel but faster, tough explanation but thats as close I as can get, any ides what this could be?? Truck seems to be working fine other than the noise and theres nothing hanging or tangled under the the truck.

[shortfatguy]

Check your transfer case fluid and your drive shaft U joints. I had my 04 doing a similar thing and didnt figure it out until it was too late. I now need a complete transfer case.

[Eric Wettschreck]

Yup, I'd be checking out the U-joints before it's too late.

[Pinusbanksiana]

Someone crawled under your truck and put zip ties on your drive shaft.

[FlatBottom]

I had a 2000 that made a noise best described the way you put it, and it turned out to be a piece of "shlage" (melted metal-I don't know how to spell it) in the cat converter. It did it at 40-43 mph.

[shortfatguy]

I was told by a mechanic that on those trucks if the u joints start going and its not caught in time it can take out the output shaft bearing on the transfer case and then ruin the transfer case. Check very well.

[Esox_Magnum]

Ok checked all fluids, good there, put it on stands and it's more of a squeek but loudest at the middle of the driveshaft???? That has me puzzled. U Joints seem to be ok but did notice the drive shaft looks like it is not welded even on the yokes, it does have an oval rotation to it, not much but easily noticable. Noise was quieter today than last night when I was pulling the boat. Could a u joint be bad but still tight enough to not get any movement out of it?

[Big Buck Buster]

Did you pull the shaft off of the truck? They usually squeak when they are dry and starting to seize. When you pull the shaft off of the truck, the joints should move easily and smooth. If it is hard to rotate them at all, replace them.

[Esox_Magnum]

Not yet going to after work tomarrow.

[shortfatguy]

I couldnt get the u joint on mine to move until I took it lose from the truck.

[RebelSS]

I'd be checking that rear end/pinion gear, even though that's usually more of a "whine". The noise going away under load is what has me suspicious...normally, if a U-joint is "tight" and has no slop or movement, it's not bad. Check your output shaft, too. Really doesn't sound like a drivetrain problem... do you have any vibration at varying speeds?

[Esox_Magnum]

It was worse with the boat on last nigh but by tonight was almost gone, I should add that it does not make any noise in reverse. What baffles me is he noise is most prominet in the center of the driveshaft. I don't notice any vibration at any speed. No cluncking or anything else and seems normal other than the sqeak noise. Also only when in forward gear does it make the noise even with the wheels off the ground.

[Big Buck Buster]

Steel, or aluminum drive shaft? The noise might be traveling through the shaft tube.

I would still pull the shaft off to see if you have any dry joints.

[Esox_Magnum]

I would say Alum the thing is huge abou 6-8" around, havent had a shaft out of anything newer than an 88 before. Rear yoke did look a little rusty and the rubber on the u joint was suspiciouse looking, dry and weathered look. Truck was not driven much untill I got it about 2 years ago and was in showroom condition at that time with 88K on it and lived it's life in a garage, I use it daily but don't abuse it. Not quite showroom now but close. Wasnt even a scratch in the box when I got it.