My truck has always sounded like it has an out of round tire. wump, wump wump, kinda noise. I thought it was that till I bought new tires. THe noise is getting worse. I took it to a shop which was hard for me to do as I prefer to do all the work myself (I have two small kids and no time to work on the truck myself). They diagnosed it as a bad outer rear bearing and I agreed to pay the dough for replacing it. OUch!!! ANyway, no better and I am out ~$700
I asked for toyota parts and I am not sure I could have don the work, it looks like a PITA to remove the bearings. I have done the front bearings and replaced the torn CV boots a while ago but that didnt help.

This noise starts at very low speeds and is gone above 45 or so. It was audible at high speeds before the bearing change, but they also dropped the rear drive shaft to check it and greased it. I am wondering if I should change the U joints and carrier bearing or if this is going to end up being the 3rd member bearings.

Any ideas?

 

I spent a good year chasing down drivetrain noise. For me it ended up being the driveshaft. After having it rebuilt and still making noise, I went with having a one-piece made (www.4xshaft.com). That fixed a higher speed vibration.

Before getting to that point, I replaced both rear wheel bearings, fixed the noise you describe, swapped differentials (found an OEM open diff on craigslist for $50, not a noticeable difference) and a new transmission (big difference in noise, but not the kind you are describing).

Did you replace both wheel bearings? If you can pull the axle out your self, you can take it to have the old bearing pressed off a new one pressed on. I think that cost me about $150 per side, bearing and seals included. Can you get the truck up on jackstands and run it up to 45mph? That really helped me track down the noise. I also took the rear driveshaft off and drove around in front wheel drive while tracking down the noise.

Best of luck, start with the cheapes (u-joints?) and work your way up.