2010JKU with JKS disconnects, AEV 2.5" dualsport lift with CA drop brackets, 1/2" front coil spacers, Bilstein shocks.

Armchair mechanic time. Coming off the last trail head on a run a few weeks ago noticed a "click" when I let off the clutch coming from the front drive train. My first thought was loose control arm bolt, shock mount, track bar or something. After wrenching those a bit the bolts I could reach quickly seemed fine but I could not get to them all so I left it undiagnosed.

Today, it's cold. So I noticed it more. I backed out of a parking spot on pavement and put it in gear. As I let of the clutch I heard the metallic click as I started forward. I did the back and forth thing a few times to repeat it and did get it to repeat rather predictably. Behaved a lot like a loose control arm bolt, clicking fore and aft with changes in momentum.

I drove around the office park and noticed it intermittently as I turned and went over small berms and raised humps of grass on the edges of the road. Playing it out, trying to diagnose.

I parked and got out, rocked it, rolled it, yanked it, tugged it...then I got under it. As I pulled on the front drive shaft to get under it rotated and I heard the click. From the front passenger tire where the shaft would enter the bearing. CLICK as I rotated the drive shaft, rotate it back, rotate it forward, CLICK again. Seems like there is some unwanted (or possibly innocent) play in there. I put it in 4L and did the back and forth dance, the clicking was present if I gave it gas, it would click as I started my initial roll forward. If I let off the gas then tapped the gas again and momentum would "lurch", there would be clicking from the momentum lurch. So clearly it's a back and forth kind of play present.

Ideas? Diagnoses? Direction?

I'm still not giving up on retorquing the whole front suspension...just too damn cold today. Clearly though there is something else wrong.

 

Sounds like the joint in the driveshaft is starting to bind - which means, it sounds like its time for a new driveshaft. Mine had a similar symptom, then not to much long past that started giving off a noticeable vibration and sort of grinding noise when going down the road.

To vet further, you could have someone drive it slowly back and forth while you look underneath at the joint (not having them run you over in the process, of course, lol). You should notice it shift or move slightly along with the click... though based on your description, it sounds to me like you've already confirmed its coming from the joint with your testing.

 

Check the rzeppa joint at the transfercase. Has that boot torn? VERY common for it to fail at 3"+ lifts. It spits the grease and runs dry. The joint has ball bearings that will get chewed up. Look at the transmission/transfercase tunnel, is there grease slung?





Sent from some string and a few tin cans.

 

Try removing the front driveshaft, and see if that fixes the problem. This happened to me and the dealer replaced the whole front driveshaft under warranty.

 

There was also a lot of grease slung at the transfer case.

 

Thanks everyone for your help and feedback. The advise was very helpful and I spent some time on my back checking everything as suggested. The only thing I could find of significance was CLEARLY the front, passenger axle shaft U Joint. Below are some photos of the separation occurring between the cap and the rubber seal. There's also a link to a video where you can hear it. These joints take a pounding from the road, and in the winters get hammered by slush, snow, sand and salt. Still, for it to fail at 55,000 miles is kinda bull, but thankfully it's under the 5/100k warranty...and if I had to do it myself outside warranty I could upgrade quickly and not so expensively. So...free for now!

https://www.youtube.com/watch?v=xJLgSzT1k9c