99 GMC Sierra Z71 Ex. Cab Rear End Noises

[Briant_k]

This might sound weird, but whenever I stop, or take off, at any speed I get a really loud chirp/squeak from the rear end. Thinking it was the bushings on my shocks sticking I purchased some silicone lubricant and sprayed everything I could find back there....didnt work. It almost feels like something is stuck and when I take off, or hit a small bump under 10mph it breaks loose, its even worse when switching in and out of 4 HI and 4 Low. Its severely irritating. If im at a stop and I rock the truck with the breaks I get the chirp when the rear moves up and down...very strange.... I read something on this forum about leaf spring pads so I called the auto store and they arent even available....any ideas?....thanks in advance,
Brian

[sierra77]

I have the exact same chirping sound in the rear of my 99 Sierra, and you were right, it's damn annoying. I never noticed it until after I replaced the original shocks. I guess I always thought it was the outer shock housing rubbing on the inner housing when it flexed.....because the shocks move a little bit even when you let up off the brake at a stop sign...the engine torques the rear axle a little bit and make the shocks move slightly. Did you ever find a solution to your problem?

[E B]

I had a chirping noise in my 97, and it was my left rear brake shoe was cracked and hanging up, hope it helps.

[Z15]

The leaf springs noises sound like someting is loose and rattling when you go over bumps, so it may not be that.

Sounds to my like bad u-joints if there is squeaking. I know, don't often asscoicated squeaking with u-joints but if the are worn out (dry and rusted needle bearings), they will do that.

Another common complain with take-off noise has been the slip yoke on the front of drive shaft. Its binds and when the suspension moves its does not slid in/out on the trans spline and creates a noise or bump feeling. The yoke corrodes and that causes the problem. GM came out with a redesigned yoke make of Nickle and recommend a good quality 100% synthetic grease.

Check out the drive shaft, 95% of the time the problem lies there. But as stated, you could have rear brake problems also.