clunking noise from rear

My 08 tundra (280k miles) produce a continuous clunking noise coming from the rear during very specific low-speed driving conditions. The first time I noticed it was when I was trying to drive out of a steep shoulder of the road. Both of the rear wheels were on the shoulder of the road. Both front wheels were on pavement. The shoulder is lower than the pavement and the shoulder was very wet. As I eased on the gas, the rear wheels couldn't get a grip and the wheels spun. During this time, I noticed the odd clunking noise coming from the rear. It's not just one clunk, but continuous clunking noise while the rear wheel spun. Not sure exactly where it came from. It could be the drive line near the yoke, the rear diff, or the rear axles. I had to engage 4 hi to get out of that situation. Once all the wheels were on the pavement, no more clunking noise.

Then again recently, I've noticed the clunking noise when I was driving out of the parking area of a public hunting area where the gravel road meets the pavement. There is a big height difference (probably 4 to 6 inches) at where the gravel road ends and where the pavement starts. When I was driving over that, I noticed the clunking noises again.

Do you folks have any idea what might be causing this? My search on the web turned up a lot of issues where it's just one clunk when folks go from stop to going to stop, and the common fix for that was to grease the yoke. My issue is a bit different in that the condition to trigger the problem is different and the nature of the clunk is different in that mine sees a continuous series of clunks rather than just one clunk.

Thanks!

 

I just crawled under the truck to inspect the rear portion of the drive shaft. I noticed that the rubber bearing in the center support is bad. Not sure if that's the culprit, but that'll certainly needs to be replaced. I also noticed that the slip yoke doesn't appear to have a grease zerk. The U join right next to the slip yoke has a grease zerk, but the yoke itself doesn't appear to have its own and appears to be sealed off.

 

Do you have LSD and have you changed oil in it recently?

 

Yeah, I have changed the diff oil and transfer case oil earlier this year about 5 months ago.

I don't think it has LSD. I think it has an electronically simulated LSD where the computer systems applies the brakes to simulate what a real LSD would do as explained in this video from Toyota: https://www.youtube.com/watch?v=IOsQdRVc0zA

 

Post a pic of the carrier bearing. They normally have some slop. Speicher makes the OEM unit for less money.