Clunk from rear end / transmission when starting from a stop - forward or reverse

[High_Country]

Got my truck (finally) two weeks ago. Took it to the mountains. Have about 2,000 miles on it now.

From day one - and even during the test drive at the dealership - I've noticed what I'll call a 'clunk' from the rear end whenever starting from a stop. It seems to do it in drive or reverse and if I apply any real amount of throttle (rolling away by just letting my foot off the brake doesn't get the clunk). It feels and sounds like its coming from the rear end/rear axle and not the transmission. It is both audible and I can feel the clunk.
The truck drives great (once rolling and past that initial clunk) - specifically the transmission shifts smooth through all the gears and I don't have any complaints about shuddering or some of the common trans problems which I'm thankful for. The rear locker engages and disengages as it should.

To ME, it feels like it could be:
a) some weird slack or backlash issue in the rear end differential setup
b) loose leaf spring u-bolts or some other suspension component allowing the rear end assembly to rotate under the torque of stopping / starting.
c) something weird with the brakes (auto grabbing and then releasing?)
d) Ujoints?

I did a search on here and found a TSB for '21's (mines a '22) about needing to lubricate leaf spring pads and block to eliminate a 'frame twist pop' - maybe it's something similar?

I was hoping it would go away thinking it just needed to break in, settle in, but it doesn't seem to be getting better (or worse).

Any thoughts / suggestions are appreciated!

 

[FaKtor34]

The truck has an electronic park brake and an auto hold function, so if your in a hilly area that could be the culprit, otherwise I would definitely get it checked out, maybe they didn't get enough fluid in the diff, there's so many different things that could be related to, and it's definitely worth getting it checked, just because if it is something screwed up, aka they tighten something down, didn't get enough fluid, it could lead to further problems in or even an accident.

 

[High_Country]

UPDATE: Finally was able to get it to the dealer (had to schedule 3 weeks out). They seemed to have found the issue:
"Identified next to no grease on the slip yoke. Added grease to the slip yoke. Issues resolved."
I only have about 20 miles on it after picking it up but it seems to have been resolved. So...yes, my shaft was not properly lubricated and it was causing problems and binding and jarring.
Public service announcement to others - if you experience similar symptoms, or perhaps if you ever have the driveshaft out fro some reason, check that your slip yoke is good and greased up.

 

[FaKtor34]

UPDATE: Finally was able to get it to the dealer (had to schedule 3 weeks out). They seemed to have found the issue:
"Identified next to no grease on the slip yoke. Added grease to the slip yoke. Issues resolved."
I only have about 20 miles on it after picking it up but it seems to have been resolved. So...yes, my shaft was not properly lubricated and it was causing problems and binding and jarring.
Public service announcement to others - if you experience similar symptoms, or perhaps if you ever have the driveshaft out fro some reason, check that your slip yoke is good and greased up.

The service department should have inspected all of that before turning the truck over to you. They should do a major inspection before ever releasing the truck, check all lube points, all fluids, all bolts properly torqued, all that should be done on their inspection before releasing it to you.

 

[High_Country]

The service department should have inspected all of that before turning the truck over to you. They should do a major inspection before ever releasing the truck, check all lube points, all fluids, all bolts properly torqued, all that should be done on their inspection before releasing it to you.

You mean the selling dealership I presume? Yeah, I'm not happy with them. I took it to a different more established / sophisticated dealer for this.
I went with a more rural, small town mom and pop style dealership for my order and ended up disappointed with their ultimate service and sticking to their word.
BUT - that aside - I would not have guessed that a receiving dealership would do something as "invasive" as removing a driveshaft to inspect for proper slip yoke greasing. Are you saying that's part of the intake inspection process before delivery? I mean, that would be awesome, but I just wouldn't have expected it to go that far.

 

[FaKtor34]

You mean the selling dealership I presume? Yeah, I'm not happy with them. I took it to a different more established / sophisticated dealer for this.
I went with a more rural, small town mom and pop style dealership for my order and ended up disappointed with their ultimate service and sticking to their word.
BUT - that aside - I would not have guessed that a receiving dealership would do something as "invasive" as removing a driveshaft to inspect for proper slip yoke greasing. Are you saying that's part of the intake inspection process before delivery? I mean, that would be awesome, but I just wouldn't have expected it to go that far.

They had my truck for 5 hrs doing their final inspection and prep before they would release it to me, they do a 150 point inspection before releasing it. They should've been able to see if the yoke was greased without pulling the driveshaft. Is it possible for them to miss something, sure we are all human, but some of the stories I've heard are crazy. I know they aimed my headlights and fog lights, they went through and lubed everything, pulled the wheels inspected brakes, checked balance on the tires, even did a 5 year ceramic coating.

 

[High_Country]

They had my truck for 5 hrs doing their final inspection and prep before they would release it to me, they do a 150 point inspection before releasing it. They should've been able to see if the yoke was greased without pulling the driveshaft. Is it possible for them to miss something, sure we are all human, but some of the stories I've heard are crazy. I know they aimed my headlights and fog lights, they went through and lubed everything, pulled the wheels inspected brakes, checked balance on the tires, even did a 5 year ceramic coating.

That’s awesome. Sounds like you got a good dealership with some know-how! I was pretty satisfied with this new dealer I went to. Will be going back for more in the future. Thanks for your insights!

 

[FaKtor34]

No problem, and yes as long as they have their current owner and service manager, I am blessed, years ago I had a good Nissan dealership and service manager, that dealership got bought out and the service manager was replaced by some ass hat from Chicago, I had free lifetime oil change and tire rotation, the next time I scheduled that I dropped off the truck, came back 2 hrs later and had a $398 bill, I asked what the charges were for and they said we changed your rotors and brakes. I said I didn't authorize that and basically went off and demanded to see the rotors and pads, got told they through them all in a big bin, i told him I could recognize mine as they weren't factory, he then gave me a look as if oh crap. Refused to let me look and refused to give me the keys. Luckily I had a friend in the local PD who came by and I took a spare key I had and jacked the truck up in their parking lot and pulled the wheels to show that the aftermarket rotors and pads that I had installed a week earlier were still in place and on the truck. They removed the charges. They were then reported to the local TV station who did an undercover investigation and released it on one of their shows.

 

[kaiser16]

UPDATE: Finally was able to get it to the dealer (had to schedule 3 weeks out). They seemed to have found the issue:
"Identified next to no grease on the slip yoke. Added grease to the slip yoke. Issues resolved."
I only have about 20 miles on it after picking it up but it seems to have been resolved. So...yes, my shaft was not properly lubricated and it was causing problems and binding and jarring.
Public service announcement to others - if you experience similar symptoms, or perhaps if you ever have the driveshaft out fro some reason, check that your slip yoke is good and greased up.

Man I have the same exact problem on my Tremor. Thanks for the PSA, I will get this checked out ASAP!! It's been bothering me since I picked up the truck.

 

[Larry]

UPDATE: Finally was able to get it to the dealer (had to schedule 3 weeks out). They seemed to have found the issue:
"Identified next to no grease on the slip yoke. Added grease to the slip yoke. Issues resolved."
I only have about 20 miles on it after picking it up but it seems to have been resolved. So...yes, my shaft was not properly lubricated and it was causing problems and binding and jarring.
Public service announcement to others - if you experience similar symptoms, or perhaps if you ever have the driveshaft out fro some reason, check that your slip yoke is good and greased up.

If you have a problem assembly the clunk will come back after about 5,000 miles, the splines on the slip yoke have been broached the same way for 50 years, they even Nickel plate the slip yoke splines to try and make the assembly slipperier and use Teflon grease. Everything has to be perfect for it not to stick, size of spline on output shaft, size and surface finish on the slip yoke, even the driveshaft angle can make it worse, I worked on this problem off and on at F---d motor co for 39 years

 

[Adventuresofozz]

My 2011 f150 had this exact problem. They applied grease and it came back a few months later. Greased again and problem never returned. My guess is that the splines are not machined very smooth and have some burrs and they they wear down with time. Just my guess. So far tremor is smooth approaching 1000 miles.