Normal Noise? or possible u-joint

[bavism]

I've been hearing a couple noises that I'm wondering if are normal and nothing I should worry about. My expy has 135,000 on it and I've had it for a little over a year. A couple of times over the last 2 or 3 weeks, I have heard a small thump from the rear. The times I've noticed it has been when I'm going about 25 and first take foot off the gas to hit the brakes. I'm not sure if i've actually hit the brakes yet. Seems to be a slight second before the brakes, but I'm not able to reproduce it when I try, so I'm not sure. It seems to be either something in the brake system, or maybe something in the suspension cause by the shifting of the body, or possible drivetrain when pressure is released. At least that's the options I'm thinking based on what/when I hear it.

Maybe unrelated but I'm also hearing a small noise when I have my foot on the brake and shift the car park to reverse, or from reverse to park. It is only a slight noise and maybe the drive shaft being engaged. I can only hear with radion/fans off. Is a slight noise that normal under these conditions, or should I not be able to hear anything engaging/disengaging? My plan is to crawl under this weekend and check the u-joints for play or anything that looks odd. And to grease them, if possible.

Anything else to look for, or should I even be concerned?

Thanks.

 

[Hamfisted]

Again, you need to put it up on a lift and check under the truck during these conditions. A common culprit is the rear axle torque arm bolts. There is a service bulletin out on that, to recheck the bolts for proper torque down. At 135k it's a little early for the U-joints to be going out, unless the Expy has been abused or used for heavy towing.


-Mike

 

[northernexp]

I diagnosed my u joints very easily after hearing a constant annoying sound when accelerating and when shifting from R to D or N to D etc. I would hear a clunk and couldn't figure it out just by listening so I went under the truck and grabbed each drive shaft and gave them a twist each way, there shouldn't be any play but the u joint was worn and I was able to easily twist the first drive shaft and immediately reproduced the annoying sound I had been hearing.

I'm not 100% sure this is your issue but you can easily check both drive shafts in less than 5 mins and at least cancel the u joints off the list.

Best of luck

 

[Red92lx]

Again, you need to put it up on a lift and check under the truck during these conditions. A common culprit is the rear axle torque arm bolts. There is a service bulletin out on that, to recheck the bolts for proper torque down. At 135k it's a little early for the U-joints to be going out, unless the Expy has been abused or used for heavy towing.


-Mike

This!! Had the exact same problem your describing.....this was the culprit!