Diagnosing Driveline Failure

dbeard

Well-known member
Oct 14, 2011
59
0
Lebanon, PA
Main goal of this post. Looking for ways to diagnose and test driveline failure. Differentials, transfer box, drive shafts, CVs. Planning on servicing diff and transfer box fluids. But other than that, what I can I do, or look for to track down the culprit? 06 LR3 with 193k on the clock.

Recently went from 19” wheels with 255/55/19 street tires to 18” 275/65/18 all-terrain tires. Went out for some fairly basic trail play this weekend, and noticed some clunking coming from the driveline when the car is navigating slow speed turns. Ended up turning around and parking the vehicle for the remainder of the weekend. We did some basic troubleshooting and observation once we got back to camp. When the car is in motion, forward or backwards at slow speeds, both high and low range, a sizable clunking can be heard, and the rear wheels are skipping. I was out of town, at a friends cabin, so needed to figure out a way to get home safely.

I have an IID tool, and no noticeable faults are popping up. I performed a self test on the rear locker, which seemed to be successful, I think. We unplugged the battery for a half hour to reset some things. After reconnecting the battery, we performed some moving tests again, and the results were much better. With the wheels turned, forward and backward moment, at first, it seemed like the clunking was completely gone. At least the large clunking had disappeared. There seemed to still be some smaller, more frequent clunking that started after some continued movement back and forth, with the wheels turned both directions.

I determined that it seemed like the car was good enough to get me home. No noticeable noises or clunking the entire way home. Seemed fine at highway speeds, and also navigating turns through intersections. Once I got home, and started to reverse into my driveway, the hard clunking returned once the wheels were turned. After a little bit of reading, I saw some folks talking about running a calibration on transfer case as a potential fix for this issue. I performed the calibration last night, my drive into to work the following morning seemed to be uneventful. Driving in my parking lot at the office involves a fairly sharp turn, and no clunking noticeable.

On my way to lunch, making a right hand turn forward, I heard some small clunking. Seemed to be because there was more load on the driveline to pull out from that turn. The more turns I took, the more I noticed the clunking happening again. It only happens if I’m accelerating while turning. If I’m coasting while turning, everything is fine. It’s not the big hard clunks right now, we’re back to the smaller, more frequent clunks.
 

Parrie

Member
Mar 26, 2019
16
0
Maine
How long after the tire switch before the clunking started? Considering 193k on the clock I'm wondering if the bigger tire caused enough strain on the drive train to break something?

Where is clunking noise? Front, rear, TC?
 

discostew

Well-known member
Sep 14, 2010
4,910
79
Northern Illinois
I bet it's your transfer case. You said something about getting the clutches calibrated. That's the first thing I would try. I've put used tcases in trucks and had the binding on tight turns till I did it
It's listed as t case replacement in the menus on SDD. Maybe some aftermarket scanner will do something similar.
The other thing I've been seeing on higher mileage trucks is the splines between trans and t case wear and then strip.