Clunk chasing- only at take off- intermittent

[Johnny O]

Ok folks, I’m stumped. All new brakes. All new suspension. U joints. You name it. All less than 200 miles…

and yet…

about 2 out of five times there is a noticeable clunk at take off. Forward and reverse.
Just went over everything with a fine tooth comb and a torque wrench…and yet it is still there.

im starting to suspect it’s what normal operation sounds like now that I’ve basically rebuilt everything!

there is literally no other noises, creaks or thumps, at idle or speed.

sugesstions?

 

[tommudd]

New tri-link ? I forget

 

[jeeptorino68]

Front or rear? Did you get the lower control arm bokts torqued to spec? That was my issue...

 

[MarksmanAkula]

Check shock bolts. When replacing rear shocks on my KJ somehow one of the upper mounting bolts came loose, causing a pop whenever the jeep moved off the line.

 

[Johnny O]

New tri-link ? I forget

Yep

 

[Johnny O]

Front or rear? Did you get the lower control arm bokts torqued to spec? That was my issue...

New LCAs installed by dealership as recall item. Checked torque all good.

 

[tommudd]

New LCAs installed by dealership as recall item. Checked torque all good

When they started replacing the rear LCAs lots of shops tightened them with diff hanging down
Then after driving some miles they had some issues
So people finally got smart and loosened then retightened them as soon as they were replaced with full weight on ground
May not be it, but something to check

 

[Johnny O]

When they started replacing the rear LCAs lots of shops tightened them with diff hanging down
Then after driving some miles they had some issues
So people finally got smart and loosened then retightened them as soon as they were replaced with full weight on ground
May not be it, but something to check

That could be it. I will try this this afternoon.

 

[Johnny O]

I did have a leaky wheel end axel seal on the driver side. I had already changed it, but dinged it up putting it in, so had to do it again. Have noticed thus far since that the takeoff clunk is still there, but is far less noticeable after the second time round. Wasn't losing but enough gear **** to make a small mess (literally 72 hours between the two). Have suspicion that those pesky parking brakes may have been contributing, as I was able to adjust them one more time since I had things up and apart.

 

[runfor5]

Could the clunk be from a bad transmission mount?

 

[Johnny O]

Could the clunk be from a bad transmission mount?

was...replaced that and the worst of it went away

 

[Squamish_Steffen]

Mine did the same for a while; clunking when the car lurches fore/back slightly during rapid gear change - for me it was the upper tri-link bushing.

 

[Johnny O]

Well folks- we found it.

It was in fact the new LCAs.
Loosened and retorqed under load as described by @tommudd and sure enough, the clunk is gone.

Thanks for all the suggestions everyone!

 

[Johnny O]

I did have a leaky wheel end axel seal on the driver side. I had already changed it, but dinged it up putting it in, so had to do it again. Have noticed thus far since that the takeoff clunk is still there, but is far less noticeable after the second time round. Wasn't losing but enough gear **** to make a small mess (literally 72 hours between the two). Have suspicion that those pesky parking brakes may have been contributing, as I was able to adjust them one more time since I had things up and apart.

Weird that “****” was censored?

 

[Tinkrr]

Ok folks, I’m stumped. All new brakes. All new suspension. U joints. You name it. All less than 200 miles…

and yet…

about 2 out of five times there is a noticeable clunk at take off. Forward and reverse.
Just went over everything with a fine tooth comb and a torque wrench…and yet it is still there.

im starting to suspect it’s what normal operation sounds like now that I’ve basically rebuilt everything!

there is literally no other noises, creaks or thumps, at idle or speed.

sugesstions?

I have experienced the same clunk with my 2005 KJ, especially noticeable after backing out of a parking spot. As soon as I moved forward "CLUNK".
My solution was to order poly urethane steering rack bushings, install them, no more clunk.

 

[Johnny O]

Just a follow up- the above methods solved the issue with stock.

used same method when upgrading to IRAs and no clunk.