Loud CLUNK when going over speed bumps

I have a 2009 Tacoma TRD Sport that's been making a loud clunk noise from the rear driver's side whenever I go over a speed bump or when there's a dip on the road and the suspension flex's, it's been doing this for about a year, I've checked EVERYTHING and can't find the issue. I can even feel it from the floor, new leaf springs were put in few years ago via recall, I just put in brand new Bilstein rear shocks, I checked the leaf spring bushings, no abnormal play, gas tank is tight, bed bolts are tight, put it in the air and shook the rear rim with no play or sound. I've read a few threads about this and no one can figure this out even though it's some what common. Has anyone had this issue and figured it out? It's driving me crazy, whenever I go over a speed bump I feel like other people think I'm driving a busted truck ‍smh

 

I am also experiencing something similar. It tends to happen when the back wheels drop off from a bump. Not from bouncing up but when they drop hard.
Shocks getting fully extended?
Is it a lift thing? new bumps?
I recently put a 1.5" rear spacer in with OME 0-2" shocks and the driveshaft spacer. No other rear end work was done. I also checked every bolt possible.

 

You don't feel it when your front wheels articulate over a speed bump, only when your back wheels articulate? If you've done a thorough inspection of all of your suspension bushings, gas tank, and bed bolts. The next place I'd look at would be your body mount bushings. Also, check your rear shocks. You might have to remove them from the vehicle to check for serviceability. I don't know a good method to check while the vehicle is grounded or on jacks. Luckily, the rear shocks are 2 bolts. I suspect that you've lost your cushioning ability. Even though they are brand new shocks, they could have failed from the factory unless this issue was present prior to you installing the new shocks. You could also check the torque on your U-bolts for your leaf springs. There are a few different schools of thought as to the correct torque value, IIRC its 25ft lbs or 52ft lbs. I'd lean towards the higher number personally. Final torque should be with weight on the ground and tighten them sequentially in an 'X' pattern evenly after you've bounced the back of the truck enough times to feel warm and fuzzy in your tummy. The threads showing on your U bolts should all be the same length.

-J

 

Thanks for the input, but I've checked all those things you've mentioned and the clunk was there before I replaced the shocks. I was jumping up and down in the box today and could here it, I think I'll call a heavy friend over and get him to flex the suspension up and down while I'm underneath, should pin point the sound then. I'll keep thread posted

 

My '16 came with a wedge in the leaf springs. So bolts may not always be same length.

 

Could your shackle hangers be installed backwards allowing them to hit the frame when the spring flexes? Also, check to see if your bed is striking the cab. Other than that, I'm at a loss. Curious to find the problem.

-J

 

Make sure the spare is winched up tight.

 

The thunk on my '16 only happens over a drop in the road 1 place in town. Have not been able to duplicate it anywhere else.
Torqued every bolt I could see.
Spare is tight. Nothing is worn or loose.
The only thoughts I have left are the tailgate or the tonneau cover is flexing bad when the back end drops hard.
Will roll the cover up and see what happens next go round.

 

Back again.
Just discovered on my driver side the lower leaf spring is off just enough to make a guide bracket rub. Will be taking care of that first thing a.m.
That can't be helping.

 

It sounds like your shock/s are reaching the end of their travel and topping out. If you've added some lift to the rear end, I'd give this a try. As long as you can get the old nuts off the top stud, these are easy to install.

 

With my 2016 I used a 1.5" block with OME Nitrocharger Sport for 0-2" lift and stock leaves.
Shocks fully extended crossed my mind but I figured that setup s/b sufficient.
I fixed the crooked leaf. Went over that same bump and still made sound. Rolled tonneau cover up, made another round, same sound.
If it isn't shocks maxing out then all that's left is tailgate.
Sorry for flooding this thread but the problems sound similar and I'm eager to get to the bottom of it.

 

"these"
link?

 

Cheap fix, avoid speed bumps

 

https://www.tacomaworld.com/threads/toytec-shock-extenders-for-stock-shocks-aal.54182/
Sorry, link didn't paste. There are multiple sources, just verify the stud size and thread pitch. I don't recall what it is.

 

Pull up on all four corners of your bed. I bet you have a loose bed bolt. If it’s not that, take the spare out and throw it in the bed and see if it still does it.

 

It wasn't the tailgate. Seeing as how I can only recreate it over one spot in the road in the city, I'm writing it off as not a problem.
Those flatter stock springs are probably over extending on that dip.
I've been underneath, on my back/all fours on the truck pushing up and getting it to bounce hard and still, no noise.

Hopefully my rambling helps OP resolve the issue.

 

You ever find the source of the clunk?

Still feels like it's dropping too hard.
I have some rear sumo springs arriving Saturday in hopes of softening that hard slam.
https://youtu.be/KHi_Fg70TSY

 

Are there loose items in the box's side cargo compartments?

 

Body mount bushings degrading are a pretty common problem. See if your radiator support bushings are flexing? There are a few threads on here discussing Energy Suspension poly bushings and a few YouTube videos as well.

 

I get “clunk” type noise on rough roads. If I grab rear of box and pull on it I get a clunk. 2017 stock suspension with only 35k miles.
Here is a video of the noise I’m getting. Changed front body mounts by the radiator as it fixed my other “clunk”. Tightened rear axel u bots. Checked torque on every damn think I can find and still getting the noise. Not sure if it’s the same noise as others. This forum is my last hope. Lol. (Not my video but same noise)

Edit; Also torqued bed bolts and bed seems solid.

https://youtube.com/shorts/8P5ddiKhB1U?feature=share