Clicking noise, but only in reverse (transfer case?)

[billlaaayyy]

Couple of weeks ago, seemingly out of nowhere (had not noticed any issue prior), my '05 TJ (SE with the 4.0) decided to click click click, but only in reverse. The sound is best described as having a baseball card in your bike tire. Youtube videos seemed to have the near-identical sound coming from the front ball joints, so I started playing parts-darts.

Quick summary......

Disconnected front drive shaft, still clicking.
Replaced front ball joints, still clicking
Disconnected rear drive shaft, replaced the u-joints, still clicking.
Re-removed the rear drive and put it in 4H. No more clicking

The click only happens in reverse and under load. When up on jack stands, there's no clicking.

It is very rhythmic in the sound, speeds up and down with acceleration, not just chaotic clunking.

Next steps for troubleshooting? I think I am being pointed towards the transfer case?

(Recent work: 2 inch lift in spring 2023, new rear-diff seal spring 2023, new bumpers spring 2024)

 

[hear]

The ball joints aren't going to give you any sort of noise that is tied to RPM or vehicle speed. You mentioned that the sound changes with acceleration. Does it change with RPM or vehicle speed?

When you put the rear driveshaft back in and heard the clicking, was it while you were stationary or only while moving? Because w/o the rear driveshaft in, the rear yoke will still spin (kinda fast, actually), even with the transmission in neutral.

If you really want to do a thing, remove the transfer case completely and start the jeep to see if the clicking remains. That will help zero in on the source.

 

[Mhass]

You replaced the rear diff pinion seal, when you did that, did you check the pinion bearing?
That seal usually doesn't go bad until the pinion bearings get sloppy...which will also give you a rhythmic clicking/clunking from the diff.
Before pulling the T-case, I'd check the pinion bearings and rear diff. See if the pinion is shifting as you go into reverse.
If your new pinion seal starts leaking again pretty quick, you can bet the bearings are sloppy.

 

[hear]

new rear-diff seal spring 2023

Let's talk about how you did this particular job. Especially setting the preload on the pinion nut.

 

[billlaaayyy]

Whoa thanks for the responses - let me try and tackle each 1 by 1!

The ball joints aren't going to give you any sort of noise that is tied to RPM or vehicle speed. You mentioned that the sound changes with acceleration. Does it change with RPM or vehicle speed?

When you put the rear driveshaft back in and heard the clicking, was it while you were stationary or only while moving? Because w/o the rear driveshaft in, the rear yoke will still spin (kinda fast, actually), even with the transmission in neutral.

If you really want to do a thing, remove the transfer case completely and start the jeep to see if the clicking remains. That will help zero in on the source.

The clicking sound is only in reverse, and only while giving it gas. When reversing slowly, its click.......click......click......click......., and as I speed up the reverse, its click-click-click-click-click. The only time there is no click is when up on stands, or with the rear shaft removed. Or at a stop, the click is only while moving in reverse

You replaced the rear diff pinion seal, when you did that, did you check the pinion bearing?
That seal usually doesn't go bad until the pinion bearings get sloppy...which will also give you a rhythmic clicking/clunking from the diff.
Before pulling the T-case, I'd check the pinion bearings and rear diff. See if the pinion is shifting as you go into reverse.
If your new pinion seal starts leaking again pretty quick, you can bet the bearings are sloppy.

No, did not check the bearing at that point. popped the cover, cleaned it all, gears all good, new gasket, sealed back up. replaced the pinion seal, good since then (until now). Did not notice any new leakage from the pinion seal but will be on the lookout. Would this be something that only shows up in reverse?

Let's talk about how you did this particular job. Especially setting the preload on the pinion nut.

that at home shop method of marking the bolt......

 

[Mhass]

If you can wiggle the yoke at all, it means your bearings aren't tight enough.
You should be able to TURN it withe the wheels off the ground, assuming everything else is OK, but it shouldn't have any side to side or up and down movement relative to the differential.

FWIW, I knew mine was going due to a pinion seal leak so, I just did it because it progressed quicker than expected and the rear differential started popping in reverse.

It does sound like your T-case COULD be the culprit also. The pinion bearing check is just easier than pulling the T-case...and I'm too old and fat to be crawling around on the garage floor dropping stuff in my eyes!

 

[billlaaayyy]

Thinking the bearings are okay. If there's any vertical/horizontal movement it's so very minimal, and no leak so that's good?

Further inspected the shaft and looks like a spline is missing. Need to remove the boot to check the male side...

 

[Rickyd]

Dana 35 or Dana 44? I never trust the nut marking method for yoke installation. Dana 44 you just torque the nut to the right spec and Dana 35 you torque the nut til you get the right rotational torque with the carrier out using a new crush sleeve.

I would be tempted to open the rear diff and check spider gears and bearings

 

[billlaaayyy]

Dana 35 or Dana 44? I never trust the nut marking method for yoke installation. Dana 44 you just torque the nut to the right spec and Dana 35 you torque the nut til you get the right rotational torque with the carrier out using a new crush sleeve.

I would be tempted to open the rear diff and check spider gears and bearings

Dana 35. And only happening when reverse is engaged. No click driving forward, no click rolling backwards (with gravity down my driveway). Only when reverse is engaged and giving it gas.

 

[Avera44]

Having the same issue. Did you find out what in the transfer case was causing this?

 

[billlaaayyy]

Having the same issue. Did you find out what in the transfer case was causing this?

Shame on me for not closing this one out with what happened.

Ended up bringing it to a shop - The rear outer pinion bearing had excessive play which was causing the pinion gear to bind with the ring gear when in reverse. Replaced the carrier bearings as well as inner and outer pinion bearings, crush sleeve, nut, etc —- good as new