2017 Silverado clunking noise!!

redwngr · December 5, 2016

A couple days ago mine had the Fast shift adapt learn done.

It's not perfect, but it is vastly improved.

Truck has about 20k miles.

17silveraDo · December 5, 2016

A couple days ago mine had the Fast shift adapt learn done.

It's not perfect, but it is vastly improved.

Truck has about 20k miles.

Was your truck clunking when you came to a stop before the fast learn ?

FL335i · December 5, 2016

TORQUE THE REAR AXLE U-BOLTS. They are very loose from the factory. I hardly ever get a clunk anymore. Search around, we found the torque spec. X Lbs + 135 degrees or something like that. Mine were super lose, like maybe 30 or 40 lbs. I think spec is 89 Lbs + 135 degrees. Again, search for the spec, I have a thread on here where we covered this.

Jeff5347 · December 5, 2016

Something I noticed and not sure if this is what you're getting....I noticed a clunking sound backing out of my driveway, coming to a stop and also while driving on dirt roads. It just seemed to appear one day. So after a few weeks of hearing it I decided to check the rear. After getting in the bed and bouncing up and down and also grabbing the rear bumper and pushing side to side ( very forceful side to side) I would hear a clunk, clunk clunk type of noise. I narrowed the noise down to the leaf spring. At the rear near the spring eye where all the leafs come together there are plastic isolators. This is where the noise was. I put a crow bar between the top and middle spring to have the plastic isolator suspended. Did my checks again and no noise. My fix was some hose...I had fish tank filter hose but assuming heater or radiator hose will work. I cut the hose and slid it between the leafs to act as a cushion. My problem

One thing on that mod I had to do was make the rubber twice as long. Letting that piece just sit there enabled it to wiggle down and then the clunk came back. So I had to lengthen it, fold it over and zip tie it tight and it stays put. I'll see if I can get pics tomorrow

solved

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Edited December 5, 2016 by Jeff5347

Donstar · December 5, 2016

Something I noticed and not sure if this is what you're getting....I noticed a clunking sound backing out of my driveway, coming to a stop and also while driving on dirt roads. It just seemed to appear one day. So after a few weeks of hearing it I decided to check the rear. After getting in the bed and bouncing up and down and also grabbing the rear bumper and pushing side to side ( very forceful side to side) I would hear a clunk, clunk clunk type of noise. I narrowed the noise down to the leaf spring. At the rear near the spring eye where all the leafs come together there are plastic isolators. This is where the noise was. I put a crow bar between the top and middle spring to have the plastic isolator suspended. Did my checks again and no noise. My fix was some hose...I had fish tank filter hose but assuming heater or radiator hose will work. I cut the hose and slid it between the leafs to act as a cushion. My problem

One thing on that mod I had to do was make the rubber twice as long. Letting that piece just sit there enabled it to wiggle down and then the clunk came back. So I had to lengthen it, fold it over and zip tie it tight and it stays put. I'll see if I can get pics tomorrow

solved

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This is good problem solving. I wold take your findings to your dealership and have a proper repair done.

dorkweed · December 5, 2016

Gonna go out on a limb here guys and say straight up that I don't think this clunking is the suspension or the slip joint. I truly think that it's fuel sloshing around in the fuel tank. I don't know if, or how these tanks are baffled on the inside, but I can duplicate this noise with the truck OFF, in PARK, and with the emergency brake engaged by pushing/rocking the truck forward and back. Sometimes I'll get the clunk 3-4 seconds after I stop the rocking...................so IMHO, it's gotta be liquid thumping. And the only reservoir large enough for that is the fuel tank. That; coupled with the fact that these trucks are relatively "light in weight", "very stiff frame", a lot of cheap/plastic parts, and likely poorly baffling in the tank.

I get the clunk backing out of my garage in the AM...............just idling riding the brake out. My drive pitches right out the door; and that's when I hear it the first time.............like clockwork...................as the fuel load shifts in the tank.

Jeff5347 · December 5, 2016

This is good problem solving. I wold take your findings to your dealership and have a proper repair done.

Thanks man, yea I have had to do a few " fixes" . I'm a tinkerer and ex- mechanic so I like to be the only one touching my stuff unless absolutely necessary. Also did the u bolts on the leafs in front of the axle...that made the ride alone so much nicer

Gonna go out on a limb here guys and say straight up that I don't think this clunking is the suspension or the slip joint. I truly think that it's fuel sloshing around in the fuel tank. I don't know if, or how these tanks are baffled on the inside, but I can duplicate this noise with the truck OFF, in PARK, and with the emergency brake engaged by pushing/rocking the truck forward and back. Sometimes I'll get the clunk 3-4 seconds after I stop the rocking...................so IMHO, it's gotta be liquid thumping. And the only reservoir large enough for that is the fuel tank. That; coupled with the fact that these trucks are relatively "light in weight", "very stiff frame", a lot of cheap/plastic parts, and likely poorly baffling in the tank.

I get the clunk backing out of my garage in the AM...............just idling riding the brake out. My drive pitches right out the door; and that's when I hear it the first time.............like clockwork...................as the fuel load shifts in the tank.

Could be. One thing also is the put a plastic cover around the tank. I noticed shutting my driver door would get a plastic vibration and found it was the cover. Still gotta wedge something in or see what I can adjust to fix that. Unfortunately plastic everywhere is the new norm. If only it was like the 50s and 60s with metal everywhere, dash, doorpanels, covers ...wishful thinking

Thus is what my leaf looks like with the hose on the leaf. This is the Dr side. I have hose on the pass side too but not folded over like this. To damn cold right now

Its ugly but it works

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Edited December 5, 2016 by Jeff5347

GMC-AT · December 5, 2016

I have been fighting the leaf springs creeks on both my 2014 and 2016. Backing up, etc.. just like you described. Going to try this as I know the issue is with that pad and/or the leaf spring bushings.

stevev · December 5, 2016

I still get a decent amount of clunking on a daily basis in my 2014. Tried tightening the ubolts and adding spring clamps, didn't really do much. Maybe I'll try that rubber around the leaf spring. Just spent 5 days with my Dad hunting and we used his 2016 F150, didn't hear or feel a single clunk from his truck the entire time. I had some F150's in the past myself and they rarely clunked.

DTOMKIDD · December 6, 2016

Gonna go out on a limb here guys and say straight up that I don't think this clunking is the suspension or the slip joint. I truly think that it's fuel sloshing around in the fuel tank. I don't know if, or how these tanks are baffled on the inside, but I can duplicate this noise with the truck OFF, in PARK, and with the emergency brake engaged by pushing/rocking the truck forward and back. Sometimes I'll get the clunk 3-4 seconds after I stop the rocking...................so IMHO, it's gotta be liquid thumping. And the only reservoir large enough for that is the fuel tank. That; coupled with the fact that these trucks are relatively "light in weight", "very stiff frame", a lot of cheap/plastic parts, and likely poorly baffling in the tank.

I get the clunk backing out of my garage in the AM...............just idling riding the brake out. My drive pitches right out the door; and that's when I hear it the first time.............like clockwork...................as the fuel load shifts in the tank.

This right here. I have a regular cab long bed and the fuel sloshes around A LOT. If I come to a hard stop I can hear it slosh back and forth a couple times actually.

I have also noticed that when going over speed bumps at an angle making the bed shake side to side there is a clunking that sounds nothing like the fuel tank. I'll be getting under the truck tomorrow to torque some things down. Hopefully that helps.

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17silveraDo · December 6, 2016

Alright guys so I talked to my dealership today and told them I want them to do a fast learn on the transmission. I'm Beginning to think it's a 2-1 downshift clunk cuz it happens mostly when I brake hard so the transmission has to downshift quicker to adjust for the correct speed. Will be bringing it back in a few days so they can do that and a few other minor things that they missed on the truck since i purchased it. Im hoping this helps . Any input on the fast learn procedure? Kind of messed up a brand new 56k truck has these issues.

Edited December 6, 2016 by 17silveraDo

FL335i · December 6, 2016

17Silverado- Did you torque the rear axle u-bolts? It's amazing what this did for my truck and others on here.... took 10 minutes in my driveway.

17silveraDo · December 6, 2016

17Silverado- Did you torque the rear axle u-bolts? It's amazing what this did for my truck and others on here.... took 10 minutes in my driveway.

Dealer torqued them down when I took the truck in the second time.

redwngr · December 6, 2016

Was your truck clunking when you came to a stop before the fast learn ?

Yes. Nearly every time. I think it was either a 2-1 shift or a 3-2.

More a a metallic click than a clunk.

It also occasionally had very severe shifts (severe enough to look to the rear window to see if there were parts on the road) in other situations. They haven't repeated either, but they were rare, and it hasn't been long enough for me to be confident they are gone.

17silveraDo · December 6, 2016

Yes. Nearly every time. I think it was either a 2-1 shift or a 3-2.

More a a metallic click than a clunk.

It also occasionally had very severe shifts (severe enough to look to the rear window to see if there were parts on the road) in other situations. They haven't repeated either, but they were rare, and it hasn't been long enough for me to be confident they are gone.

I hope when they do the fast learn that it is a huge improvement. Its definitely one of two things either transmission downshift clunk or axle wrap causing it to bind on the slip yoke. My noise is more of clunk/thud. Sometimes so loud that it feels like something is loose and moving by the transfer case. Edited December 6, 2016 by 17silveraDo