Rear right side thud after lift kit **FIXED**

[Dirtrider216]

EDIT I LOOKED AND I HAVE 2 RCC2.0HD springs under the car
I started to notice a few days ago that there is a considerable thud coming from the back end of my car when I go over larger bumps or holes..
Tonight I spent some time mall crawling off of curbs and isolated it to my rear right side and it happens every time the wheel drops and catches itself again..
I can’t figure out what would cause this.. could I have a shot bushing somewhere? If so how would I find it? Or could I have gotten one superflex and one superflex HD spring from toytec and the Hd spring is just stiffer and that causes the thud? Is there any way I could look to see that?
Also it doesn’t seem that this happens upon compression before the drop
Like if I go up the curb it doesn’t make a sound but driving off the curb it does
My rear setup is blistein 5100s and what I had thought were a set of superflex HD rear springs and my sway bar removed
I went with HD when ordering the lift because I have a storage box made from 1/2” MDF and it’s full of tools and supplies probably totaling close to 150 pounds

 

[Dirtrider216]

Just had the car jacked up at the frame and when I began letting it back down I let the jack off quickly and it made a definite creak that upon higher impact I think could be the thud I’m hearing.. no idea what it’s from though.. could the spring be seated poorly? I pulled and jerked on things under there with the frame jacked up and tire off the ground but nothing seemed loose

 

[Rodtheviking]

I would check the upper and lower control arm bolts, its possible they loosened one to help get the axle to drop and didn't torque it back when done. And the panhard bar while you are at it.

 

[Dirtrider216]

I would check the upper and lower control arm bolts, its possible they loosened one to help get the axle to drop and didn't torque it back when done. And the panhard bar while you are at it.

Would I do that with the car jacked up or with the weight of the car on iy

 

[Mike07SE]

Would I do that with the car jacked up or with the weight of the car on iy

All suspension components should be torqued with the weight of the truck if possible.

Sent from my XT1254 using Tapatalk

 

[jrm]

Check the traction

bar bolts. I had one that was loose and before it was found and tightened it mafe the same creaking and thunk noise that you have..

 

[Dirtrider216]

bar bolts. I had one that was loose and before it was found and tightened it mafe the same creaking and thunk noise that you have..

Bar bolts? Like the bolts on the lower control arm attaching the frame to the axle? Or the one that runs parallel to the axle diagonal from the ground

 

[jrm]

Runs above the rear axle

Bar bolts? Like the bolts on the lower control arm attaching the frame to the axle? Or the one that runs parallel to the axle diagonal from the ground

and parallel to the ground.

trac bar bolt is on the right if your looking at the rear of the truck. Dumbass that replaced my rear springs didnt tighten the bolt.

 

[blackoutt]

When you read a response from jrm you have to read the title of his post too which doesn't show up on tapatalk so you gotta login to see his full thoughts if you want the first 20 or so characters lol. He said TRACTION BAR bolts.

"Check the traction

bar bolts. I had one that was loose and before it was found and tightened it mafe the same creaking and thunk noise that you have.."

then

"Runs above the rear axle

trac bar bolt is on the right if your looking at the rear of the truck. Dumbass that replaced my rear springs didnt tighten the bolt."



Another thought is that the 5100's are actually too short of a shock for a 2" lift spring, mine used to clunk all the time when turning right into my neighborhood and the rear wheel on the inside of the turn (right rear wheel) would drop a little bit into the drainage feature where the two streets intersected. It drove me insane! Longer shocks to let the wheel droop into that little depression in the road and the clunk is gone.

 

[Dirtrider216]

That makes a lot more sense thank you for pointing that out! I’ll look into both of those when I get a day off and the temperature gets back to double digits
Hopefully it’s just the traction bar because I really don’t want to fork out for new shocks considering I don’t do any off-roading beyond hunting trails for now

 

[Dirtrider216]

Picked up a 20” breaker bar at Lowe’s and crawled under the truck to tighten things, I got 1/4 to 1/2 turn out of all the 3/4” bolts under rear of the car on both sides..
Getting ready to go on a test drive to see if the thunk is still there

 

[Prommy]

Picked up a 20” breaker bar at Lowe’s and crawled under the truck to tighten things, I got 1/4 to 1/2 turn out of all the 3/4” bolts under rear of the car on both sides..
Getting ready to go on a test drive to see if the thunk is still there

Let me know how it goes; I think I may have a similar issue.

 

[NinjaOne]

You put the spring isolators back in when you installed the lift?

Check the swaybar links links and bushings. Make sure the swaybar brackets are tight

 

[Dirtrider216]

You put the spring isolators back in when you installed the lift?

Check the swaybar links links and bushings. Make sure the swaybar brackets are tight

A shop did the work on the lift kit so I’m not sure about spring isolators
I had the rear sway bar removed because I didn’t think I need it

 

[NinjaOne]

A shop did the work on the lift kit so I’m not sure about spring isolators
I had the rear sway bar removed because I didn’t think I need it

That should be a rubber cone thing at the top of the rear springs (right side of image below)_

There should also be bushings above and below the frame mounts for the top of the shocks. Make sure they didn't forget one

And as mentioned by others, torque on the rear suspension arms and check wheel torque.

 

[RainyDayRunner]

I did my own suspension and tightened it all back to factory torque settings. My did the exact same curb hopping last night and also got the thud. I am very suspicious of the spring seat on the rear springs. The springs don't completely seat all the way around. They are seated in the notch, but not on the back side.

When I got home, I checked the spring to see if it had seated completely to confirm the source of the thud. It had not. Here is what I think happened:

When I went up the curb, the spring compressed, expanded slightly, and fully seated itself. When I dropped off, the spring extended and pulled away from the seat, like it had been before. The thud was probably when the spring popped back up.

Keep us posted. If it is still happening, I am going to see if I can get mine to do it consistently. Then I'll mount a gopro underneath to see if I can catch it on video.

Sent from my SAMSUNG-SM-G900A using Tapatalk

 

[Dirtrider216]

UPDATE****
It seems that tightening everything under the car fixed it. I can’t say exactly what was contributing considering that every 3/4” bolt I saw under the car I managed to tighten some more front and rear on the control arm and both ends of the trac bar
But I have been doing the exact same things as before and haven’t managed to replicate the sound since I tightened things so I’m going to tentatively say that it’s solved!

 

[Rodtheviking]

Sweet