Hellwig 991 helper spring makes clunking noise

I recently installed the Hellwig 991 helper spring on my Tundra. The ride is good, but when I go over dips or high bumps, there's a clunking noise coming from the rear. I checked all bolts and nuts and they look good. I guess the Hellwig U-bolts don't hold the spring with enough tension, so when the springs get compressed under tension, the Hellwig U-bolts rattle and move sideway. Does anyone have that Hellwig 991? What do you think the problem is?

 

Assuming you’ve installed it correctly, the problem is the design is an after thought. In other words, its effective for loads but not on bumps or when empty.

 

I have the 991s installed but have never noticed a clunk.

I did notice that one end of the leaf is longer than the other and if you put it in facing the wrong direction, the U bolt that it comes with barely grabs the end of the second leaf.

Maybe that’s what happened?

 

Try tightening them down little more, if they are indeed unloading, that should help. On mine they wouldn't tighten down far enough so I had to use some spacers before the nuts to allow me to tighten them farther.

No clunks or any noise at all

 

This picture is not my setup, but mine is similar except the nuts don't go deep in the U-bolts. They're where I drew the red marker. Do you think that it doesn't have enough tension and it causes the clunking noise?

 

Snug’em down and find out. Worst case senario is you unsnug back to prior.

 

Yes.

 

Yup. I have mine as tight as they would go and then backed off a few turns to get the truck to sit level.

I will say that even when they were as tight as they would go, I didn’t notice a decrease in ride quality. Give it a shot and report back.

 

Thanks gents. I'll turn the nuts deep in and see what'll happen.

 

That's what she said.

 

After I first installed it, the front of the truck went out of alignment. Maybe it's a coincident. Will the stiffer rear cause the front to go out of alignment?

 

No. But dips, potholes and high bumps can.

 

I turned the nuts in for another 5/8" and the clunking is gone. The ride is firmer, but it's acceptable since I replaced the new shock. I can't wait to tow my boat to see how it handles.