Alright all you drivetrain guru's what's my problem?

I have a 2000 5.4 4x4 with just over 94,000 miles on it, I get a click or clack sound from under my truck when I do the following, I think it might be my u-joints going bad, what say you?

- Shift into drive.
- Accelerate from a stop, either forward or backward.
- At slow speeds accelerate then let off the gas then accelerate again, in other words put tension on and off the drive-shaft.
- Turn while driving slowly going over an uneven surface that twits the suspension, like turning into a parking space that has a dip or bump in front of it. (this one really makes some noise!)

Thanks in advance for you opinions...

 

It should be more of a "clunk". If it is the U-joints you can get under the truck and turn the driveshaft back and forth by hand to see if they're bad.

Tracking down sounds from under the truck can be a nightmare.

 

We need a little more information please.

Is the noise in the front, rear, both? Maybe in the center underneath? Could you get a person to help you narrow down the noise location?

It could be a limited slip diff chattering, u-joints, cv joints, tranny or t-case mount, engine mount or many other possible things. It could even be ring and pinion noise, or a worn out pinion bearing. The possibilities are endless.

 

Here's a little more info:

- I do have a problem with the slip-yoke leaking slightly at the transmission when I off-road and twist the suspension a lot it's almost like the driveshaft has some play in it.
- I had new 4.10 gears front and rear installed and a Truetrack LS within the last 9 months, problem did not exist before then.
- It sounds like the noise is coming from the center underneath, is not a "clunk" it more like a "clack" or "click" not overly loud or pronounce like some play is being taken up between to pieces of metal.
- The front-end has been completely gone through and given new tie-rod ends, idler arm, replaced any bad ball-joints and one CV joint.
- The pinion seal has been fixed for a leak 2 times and still has a slight leak.

 

I'd start with a pry bar and start looking for play under the truck. Check the u-joints, CV at the t-case (looks like 2 u-joints), output yokes on t-case, tranny mounts, engine mounts, etc.