mysterious clunk in front end

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Joined
Dec 10, 2017
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Location
Georgia
My Car
1973 Mach 1 "Q Code"
I thought that I had this fixed a few months ago because the intermittent clunk when turning hard left to the stop and then back right about a quarter of a turn disappeared after torquing the ball joints and down to specs. Now all of a sudden a couple days ago, I noticed the clunk was back. It happens right about a quarter turn from the left stop going back to right. I jacked up the drivers side and rocked the tire back and front, left and right and no movement. I have not checked the torque on the right side wheel bearing yet and that is probably the only thing that I have not checked. The front end upper and lower control arms are new (upper and lower arms with ball joints, inner and outer tie rods changed). I did use the original idler arms but visually, they looked good. And I used a power steering box from my parts car. The pump is new. The front disk brakes are a Wilwood kit that had the bearing and all associated parts in the kit.
Could the right side bearing be causing the issue, I plan to check that tomorrow night? Could the steering box be binding up and causing the issue? The front tires turn freely but can someone walk me through proper wheel bearing adjustment incase I am torquing the down wrong? Thanks in advance.

Tom
 
I think I have the same clunk. It might be my transmission cooler lines…it might be my anti roll bar has minimal clearance. I can’t find any rub marks…also my left torsion bar is not tight in the front crossmember…I have worked on it myself, and taken it to 2 shops, it continues to have play, but the front end is aligned good. I also have a mostly new front suspension. Center link and steering gearbox are original. But control arms and bearings, bushings and tie rods are new…
 
Is there space around the eccentrics? Any space will allow slight movement with a fairly loud pop.

You might also look at eccentric eliminators if there is slop. I got the ones from Opentracker racing. Since they are horseshoe shaped they are easier to install as you don’t have to pull the bolt out to change them like some others.
 

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Another area to check is your strut bushings at the crossmember. I didn’t mine correctly torqued after restoration and had a significant clunk. Much better when torqued to spec.

If it has not been restored, the bushings up there could be rotted or degraded.

Good luck!

Kcmash
 
Another area to check is your strut bushings at the crossmember. I didn’t mine correctly torqued after restoration and had a significant clunk. Much better when torqued to spec.

If it has not been restored, the bushings up there could be rotted or degraded.

Good luck!

Kcmash
Thanks Kc, yes they have been changed. I need to reverify their torque. I downloaded the torque spreadsheet this morning and will go through everything again this weekend.

I did check the passenger side wheel bearing tonight and the clunk is still there. This is leading me to the gearbox which is the only thing on the steering that I did not change out (other than the idler arms which I hear are not available). I will verify torque again on everything including the idler arms (that were from my donor car) this weekend. Hopefully I can get my wife or son to do some steering for me while I am underneath and I can see where the clunk is coming from. More to follow soon.

Tom
 
Is there space around the eccentrics? Any space will allow slight movement with a fairly loud pop.

You might also look at eccentric eliminators if there is slop. I got the ones from Opentracker racing. Since they are horseshoe shaped they are easier to install as you don’t have to pull the bolt out to change them like some others.
Ding, ding, ding, we have a winner. The bolts to the eccentrics were bound up pretty tight and would not turn when weight was on the front end. When I went back through, I checked the torque on the actual nuts and they were way below the torque. I remembered that when I installed the front end components, I did not have the engine in and decided to torque everything down after I put the engine in with weight on the front end. Apparently, I just used the torque wrench on the bolt heads instead. It took a bit of effort but I pulled everything back apart tonight and cleaned the eccentric bolts and re-torqued them back down. No clunk now afterwards. I will recheck the torque again after a couple hundred miles.

I really appreciate the advice given as all of the comments were very insightful and helpful. Thank you to everyone.

Tom
 
Ding, ding, ding, we have a winner. The bolts to the eccentrics were bound up pretty tight and would not turn when weight was on the front end. When I went back through, I checked the torque on the actual nuts and they were way below the torque. I remembered that when I installed the front end components, I did not have the engine in and decided to torque everything down after I put the engine in with weight on the front end. Apparently, I just used the torque wrench on the bolt heads instead. It took a bit of effort but I pulled everything back apart tonight and cleaned the eccentric bolts and re-torqued them back down. No clunk now afterwards. I will recheck the torque again after a couple hundred miles.

I really appreciate the advice given as all of the comments were very insightful and helpful. Thank you to everyone.

Tom
Excellent!

Glad you were able to figure it out and thank you for reporting back. Hopefully it will help someone else with the issue down the road.
 

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