Resolved: Diagnosing a thud when above ~40 mph

This has been going on for a few months but it does not do it often.

If you are approaching highway speeds, let off the gas, then quickly give it gas again, there is a clunk that seems to come from the rear end. The timing has to be just right.

I had something similar a couple of years ago and it the transmission mount. This seems to come more from the rear-end.

 

So you're 2WD then, and you checked the bolts on the transmission crossmember, they're all 4 there still, and more-than-finger-tight?

 

The shop supposedly checked that last time, but I will recheck

 

Only takes 30 seconds to slide under the truck. Wanna say it's a 14mm bolt.

 

They were in good shape and The transmission mounts had been replaced last year if I'm not mistaken

And the transmission shop confirmed they were there since I had to have The transmission redone earlier this year



i'm under the truck, checking the torque on my driveshaft bolts and started looking again for this clunk/thud.


I haven't found a video online, but it seems like I have about the right amount of play in the carrier bearing And all else seems tight. Of course I can't re-create the torque you get while driving at above 40 mph.

I just went back through a lot of my maintenance records and I've noticed two different shops that tried to locate this ended up noting that it was just normal for a high mileage truck. I don't buy this BS and I don't like clunks. Not good for the rest of the drivetrain imo

is there a bearing or something else in the differential that would wear and cause enough play? All the joints have been replaced. This is more than just a noise, you can feel it above 40 miles an hour when you let off the gas and then give it enough gas to accelerate. So it doesn't do it all the time but I can re-create it. It's not an uncommon situation that you would get driving down the interstate for instance

 

Also, I guess this grease splatter/spray is normal

 

With the truck in park, lie underneath & rock the truck forwards & backwards, see if you can see or hear any movement at the pinion.

 

I could not. You are talking about the steering rack, correct? I do have one on the way to replace that, but this is most definitely in the drive train in the rear of the truck or at least that's where it manifests.






also nuts on the driveshaft flange to the differential were still torqued appropriately to 54 pounds

 

Spatter is normal.

If you jump up and down on the bumper, any noise? What about rocking the truck forward/back pushing by the bumper? Trying to rule out broken leaf, dicked up hanger, etc. All the hanger and leaf spring nuts/bolts intact and good?

Who installed the new carrier bearing and u-joints etc.?

I'm guessing this isn't your issue, but posting it here for S&G: https://www.tundras.com/threads/tick-when-i-shift-into-drive-or-reverse.129947/

And obligatory FSM page for carrier clocking etc.

 

Commenting to follow. My truck will also randomly do a clunk. Carrier has a little play, but nothing that seems to be of concern. Can't find the source after spending an hour under the truck wiggling shit around

 

Also, just to note this has been an issue for over 40,000 miles.

Obviously it's not something that happens routinely. It is past time to get this resolved especially since it is now my daily driver again

 

No. rear axle pinion, where the driveshaft connects to the rear axle. But that would probably make more of a clunk when shifting into drive or reverse from a stop.

 

Yes, I have tried that

I rechecked all of the leaf U-bolts and nuts while I was under the truck just now. But the sound was there before I replaced the shocks the four U-bolts last October

By God if I end up having to put a dang camera up under here so I can watch the driveshaft while I'm driving, I will do it

 

The way I ended up isolating my rear-end clunk was stupid. It didn't make the sound jumping on bumper, only if I jump up and down on the back half of my step bars.

Then I got under the truck, tucked my knees up under the spare tire rubber, and pushed the truck up and down, which pointed me to the driver leaf. Got my head a little closer and tracked it down to one specific spot on the leaf spring. Filmed it, sent ATS some videos of it, they couldn't explain it, so they sent a new spring.

@Weagle one other question, you know there is supposed to be little plastic discs/shims in between each leaf spring in your pack, at both ends, right? Are all of yours intact? They fit in the little holes. Dorman sells replacements at most LAPS.

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Ah, that makes more sense. Could that be the four nuts I just re-torqued?

 

I'd expect some vibrations too. I think this is probably something slapping something else.

 

I couldn't quite tell where that was located so I tried to take some pictures of my set up. Not sure if I got the part you're referencing.

 

no, its the big nut in the center of those.

when you put the gopro inder there shift from d to r a few times & watch those lift blocks.

 

Check on both ends of the springs, in between each leaf, that (A) you see a nub there, and (B) there's a 3-4mm plastic disc on top of that nub, providing a coushin to prevent the leafs from slapping together. It's a common rear source of creak and squeak. (Although I suspect pinion, but that's another topic)

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Ok will do

going to change those out to either an add-a-leaf or replace the leafs entirely next year. Just waiting to see how much lift I end up with on the front end so I can raise the rear appropriately to maintain some rake I'm probably gonna raise the front up one more notch on the adjustable bilsteins. I think that is just shy of an inch which would give me almost 2 inches total lift on the front

 

it would be on the top side of that nub/top of the leaf?

I will double check that but I called myself feeling up there and did not feel anything after your previous post

edit: ahhh you said between. I did not see anything, but I'll look a little bit closer.


I will add though that this feels like something loose - more of a jolt maybe?? More than just something slapping together.

 

Watch this video, it hopefully will make sense. Best video I could find in a pinch. Again, I don't think this is it, but I do think it's worth confirming, all your insulators'isolators are intact and whole.

https://www.youtube.com/watch?v=93mw-sCq8iw​

 

Good video. Would've never even known about those Leaf isolators

they all appear to be there, although I need to look closer at the passenger side. There appears to be two on each side toward the cab in one at the rear

A little worn, one has a split in it and probably a little compressed over over the years Not sure if this is an issue, but it looks like an easy replacement that needs to be done given the age and mileage

 

Nah, as long as the disc is at least 75% intact (cracks aren't a biggie), it should be fine.

Those damn things are a common source for clunk/squeak/rattle out of the rear end.

 

The center support carrier bearing is disintegrating. I still doubt that it's what is causing this clunk that continues to get worse

I was under there starting to work on my rack and took another look.

The U-joints all have a grease fitting. 3 fittings is all I could find. That's not the way a 06 2WD double cab is from the factory, correct?

U joints were done before I started either doing my own repairs and/or at a minimum buying all of the parts myself. I had no idea mine have grease fittings and sure they have not been greased appropriately.

 

Correct. And that carrier should be replaced. Go spicer.

 

This seems to have been resolved by replacing all U-joints and the carrier bearing. Since whoever did my joint before beat up my driveshaft, I had to replace the driveshaft as well

 

Ooof. I wouldn't doubt if it was the carrier, just surprised to see no report of vibrations to go along with it. I also wouldn't doubt if the clonk was the u-joints, but they should've showed some sign of play (IMHO) if actually bad. Glad you got it resolved.

 

It had started vibrating. It started right after I got the new tires. For a few hundred miles it was smooth as silk. Then I thought it must've lost a weight and the tires were out of balance. However, it turned out to be the carrier bearing. Once it was replaced, the vibration went away.

Oddly, if I'm not mistaken, that carrier bearing had already been replaced Last year

 

Bad u-joint will cause carrier to fail in short order (and sometimes other bearings, pinion, etc.)

All it takes is a little vibration in the driveline to make other things upstream/downstream fail. To that point, if the PO who replaced the u-joints damaged the driveshaft, or somehow impacted its balance, that could've done that.