Noise when accelerating at certain speeds - rattling/growling near front

[centuryhouse]

I have a 72 GMC longbed w 350 engine and turbo 350 trans, two piece drive shaft.

I took it to work today and a new noise is present when accelerating, but only a certain speeds - around 5-10 mph, and around 30 mph. So that is in two different gears - first and third (?).

The noise is kind of a roaring, growling, almost rattling sound - kind of a cross between how power steering sounds when it is low on fluid, and how a diesel truck sounds. It does NOT seem to be from the engine.

* The noise stops immediately I pop it into neutral.
* The noise also goes away in gear once I pass the speeds in question, and the truck drives and feels normal.
* The noise is NOT replicated if I give it gas while in gear with my foot on the brake.

I thought wheel bearing, but it stops when I pop the trans into neutral, so not that.

I have replaced the two u-joints on the rear drive shaft, and replaced that rear yoke at the carrier bearing. I have NOT replaced the carrier bearing or front u-joint at the transmission.

Could it be the u-joint or carrier bearing?

If not, is there something in the transmission that could do that?

[davepl]

Carrier bearing can be responsible for a lot of things, and while I hate to throw parts at any problem without a proper diagnosis, part of that would be ruling out the carrier bearing. So if you can check it, check it. If its old, replace it.

I just had to have my stub and yoke (behind the carrier) replaced due to wear. It solved a narly vibration I was having that I still don't believe it fixed, but the problem is gone.

[centuryhouse]

Originally Posted by davepl

...ruling out the carrier bearing. So if you can check it, check it. If its old, replace it.

I read some conflicting things - is a press/puller required for that?

[davepl]

Originally Posted by centuryhouse

I read some conflicting things - is a press/puller required for that?

I used a press to install it, but couldn't get it on all the way, so the shop pounded it one with a hammer and a piece of pipe. So I guess it can be done multiple ways.

I think I used a press to remove it.

[centuryhouse]

OK. It looked like it would just slip right on out. In that case, I'll see about taking the whole truck to the driveshaft shop.

My only concern is the truck not making it all the way there. But I'm not supposed to do any car work where I currently live (not stuff as obvious as blocking the wheels, getting under it to work, etc), so that sounds like a good option.