Problems after new upper control arm, your thoughts?

07 9-7x 5.3. Had noticed a front end vibration at 70+ and an occasional slight pull to the left only when braking so I took it to a trusted shop. They said my right upper control arm bushings and ball joint were bad so they replaced the UCA. Truck immediately pulled hard to the right. Tire even squealed driving straight. Took it to another shop for alignment (1st shop didn't have a rack), and they were able to stop the pull when driving, but were not able to get the alignment within spec. AND it now pulls very hard left when braking. Any thoughts? (yes, they verified the settings were correct for 9-7x and not the model named in the paperwork).
 

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Eric04

Silver Supporter
If you're now rolling straight and smooth but it pulls only when braking, check for a lazy caliper. It may be the side opposite the pull isn't engaging much at all. Or the pull side is grabbing full while the other is slow...best to replace in pairs anyway if suspect.
 

flyboy2610

Registered Member
The first thought that comes to mind is that the first shop didn't install the correct part. For the caster to get off that bad, I wonder if the first shop installed a left side UCA instead of a right, although I don't know if that's even possible.
 

flyboy2610

Registered Member
To expound a bit on my previous post, go outside and look at the UCA on the left side of the truck. You will notice that the ball joint is more towards the rear of the truck than the front. Now go look at the right side and see if it more towards the front than the rear. If it is they put a left side UCA on the right side of the truck.
 

Mooseman

Master Blaster
Moderator
Recheck the LCA bushings. I had a hard pull only while braking because they were so worn it moved 1/2" on one side.

And not everybody knows how to adjust the LCA bracket for proper alignment on these trucks. And not all shops are created equal. I recently had this problem with 3 different vehicles at the same 2 year old shop and honestly think it was their equipment because multiple tries and technicians had the same bad results. Finally found a shop that knows how to do alignments.
 

gmcman

Guru
And not everybody knows how to adjust the LCA bracket for proper alignment on these trucks
This brings a thought, some shops may not be aware of the bolt torque for the LCA brackets. The two smaller bolts are 177 foot pounds, and the larger bolt is 195 foot pounds.

I had an alignment performed after I changed mine, they didn't tighten them fully and after a hard brake, the driver side bracket slid backwards, taking all the suspension backwards thus knocking the caster way out of whack.

Would be easily noticeable.
 

gmcman

Guru
@Sid Coleman Not sure if this is your issue, but this is what my driver side looked like after the suspension slid backwards due to the LCA bracket not being tightened enough. This really jacked up my caster, note the close proximity of the rear of the tire to the wheel opening.

Edited to change camber to caster.

Screenshot_20211010-151945_Chrome.jpg

Screenshot_20211010-151921_Chrome.jpg
 
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Sid Coleman

Newbie
Thread Starter
Just looked it over-looks like the right UCA is upside down-is that possible?. The wheel placement in the wheelwell is much further to the front than the driver's side. Taking it back to the shop tomorrow. Thanks again all!
 

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Eric04

Silver Supporter
It's increasingly hard to believe what passes for professional work. Not one, but two shops missed that error. Good grief
 

TollKeeper

Gold Supporter
A lot of shops will also not align a GMT360 correctly, saying the lower arms arent adjustable, even thou they are.
 

Mooseman

Master Blaster
Moderator
Just looked it over-looks like the right UCA is upside down-is that possible?.
Yes it is. In fact, this is a mod that's done by those that lift their trucks however, they are flipped and switched sides. because it wasn't switched sides, it's no longer centered.

This is a good example of why you have to do your own work :mad:. Unfortunately we can't do our own alignments.
 

flyboy2610

Registered Member
Yup! They installed it upside down! This would have the same effect as installing a left side UCA, moving the tire too far towards the front of the truck, which is why your caster is so far out and the second shop couldn't get it adjusted. I had to do as Mooseman mentioned, swap sides and flip them upside down because I put a 2" leveling kit on mine.
You also have a secondary issue, besides the caster, and that is that the upper ball joint is no longer at its proper angle. It looks to me like its pointed towards the engine, when it should be straight or slightly angled towards the fender.
If you're mechanically inclined and have a set of tools, it's really not hard to flip that by yourself, but I would take it back to the first shop and have them do it on their nickle! And have them pay to have it re-aligned!
The "flat" side of the UCA needs to be on the bottom, and the rounded side on the top. Look at your left side UCA and you'll see what I mean.
I really thought they had put the wrong part on. I never guessed they put the right part on, but upside down. I get 50% for my answer, I guess.
I must say, that's a new one for me!
 

flyboy2610

Registered Member
A lot of shops will also not align a GMT360 correctly, saying the lower arms arent adjustable, even thou they are.
Or they say they don't have the "special tool" that GM says you need to have. Just ask them if they have an impact wrench and a pry bar. That's all you really need. Well, plus the alignment rack, of course.
 

Mektek

Hobbyist
Sure we can do our own alignments!
When I replaced a tie rod end - the home alignment was good. Lately, I replaced all the front right side bushings. Took it for a ride today and it drives well. I found that it was easy to install the LCA bracket in exactly the same position as it came out. When I replace the bushings on the other side, I'll check the toe since I aligned it previously with the old LCA bushings that were offset approximately 1/8". I'm going to take a technological leap and build a laser alignment rig.
 

gmcman

Guru
I'm going to print out the alignment thread including the bolt torque specs
Just be sure to note, the 2 smaller bolts in the rear get the 177 ft.lbs, and the larger single bolt in front is 195 ft.lbs. Also make sure they use penetrating oil to loosen them, you don't want to have to mess with breaking off the welded nuts.



Glad to hear your issue is resolved. Also, doesn't the ABS sensor clip into a slot on the upper control arm? If so, you would think a dangling wire would have been a slight clue something was amiss.
 

Sid Coleman

Newbie
Thread Starter
Just be sure to note, the 2 smaller bolts in the rear get the 177 ft.lbs, and the larger single bolt in front is 195 ft.lbs. Also make sure they use penetrating oil to loosen them, you don't want to have to mess with breaking off the welded nuts.



Glad to hear your issue is resolved. Also, doesn't the ABS sensor clip into a slot on the upper control arm? If so, you would think a dangling wire would have been a slight clue something was amiss.
Noticed it was zip tied-now I know why. Thanks!!
 

TollKeeper

Gold Supporter
No doubt.


You would think, the tech who removed both sides then only re-attached only 1 correctly, then added a zip tie to the other....would have paused for a scratch-your-head-moment.
I can actually see how they missed it. Those clips dont really come out of the control arm without breaking, UNLESS you are replacing the hub with ABS wire, and only if that ABS wire came with that loom retainer. Mine are currently zip tied on from when I replaced the entire front suspension. The slot is there, I just dont have any loom retainers to plug in.

I also dont think the control arm is upside down, I think its on the wrong side, as these are side specific. But as I have not done this mod, I cant swear to it..
 

Eric04

Silver Supporter
That's the thing. I can't see how one doesn't match up parts when replacing. It's like 101. Further, every alignment shop I've used has been nitpicky as heck about front end component wear levels, always with feedback about any suspect parts. A trained eye should see the asymmetry on that side. That's why you pay them. Allegedly.
 

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