Unacceptable: tubular upper control arms with no bump stop pads.

[DionR]

The openings in the frame are within 1/16” of each other in the car. Right side is 9 1/2”, the left is 9 7/16”.
When Rich installed the right UCA, it fit right in with a little persuasion. The left side though… the overall width of the arm was a strong 1/8” bit not quite a quarter wider than the car. Not ideal but given that the car itself measured 1/16” narrower there, I just milled the aluminum spacers and moved on.

Ah. Base on that, it sounds like the arm was maybe only 1/16" or a bit more too wide. I would have smacked the mount with a rubber mallet a bit and I bet it would have slid in. That's what I had to do to get the SPC 1.0 arms installed last week. Didn't take much persuasion in my case, but this is the arm that has the thread legs so it was just the width between each ear that was an issue.

I wouldn't say the arm was mis-fabbed in that case.

Now the barrel not being in plane so the adjuster works is a different matter.

 

[jos51700]

Exactly. In fact, I think the auto industry as a whole would benefit from having retired mechanics as engineers.

It isn't the engineers. It's the bean-counters. I fight the money people over stupid **** they want to change to save a penny, every damned day.

 

[BergmanAutoCraft]

Millions of these cars were built and despite some sloppy tolerances, the dimensions are not that different from car to car so why does THIS happen?

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This aftermarket tubular upper control arm front bar misses the bump stop by a mile.

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Really? This is supposed to be acceptable? Maybe the right side is better.

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Uhhh….

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No, it is just as shitty as the left side.
These are PST products. They were a fight to install too, being too wide on the left side by 3/16”. I had to mill down the aluminum spacers to get them to fit in the car. Oddly, the right side went right in.
As it stands, I could weld on a flat tab on the front bars but that means prep and a repaint of the UCAs.
Just for a quickie fix, I made offset brackets.

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I shouldn’t have to do this. Last year I installed a set of QA 1 arms and they had the bump stop pads welded to the front section on each one. This is shoddy work.
These offset pads will work but they shouldn’t be necessary. I’d weld on tabs like the QA -1 UCAs have but I’m pressed for time. I’d have to pull these off to get a good weld to them then there is the prep and paint…
Just a warning to you guys…. These UCAs may be great otherwise but this one part really sucks.

Why would you buy those when we have the ultimate arms available?

 

[340sFastback]

So now what? Take PST arms off, put up for sale or send back, get something that fits?

 

[Kern Dog]

Neither Rich or I in good conscience would feel right trying to sell these. The right side is just wrong. Maybe PST will accept these back, inspect and then decide if they will refund. That remains to be seen.
We put the stock arms back in. The upper ball joint zerk to bumper bolt was identical from left to right. It was 1/2” off with the PST arms.
Camber on the right was 3/4 degree NEGative with 3 5/8 degrees of POSitive caster. This is with the alignment cam bolts set almost exactly as they were with the PST arms aside from the front cam bolt being out of square in the PST arms.
The left side was aligned to rest at 3/4 degrees of NEGative camber and 3 1/4 degrees of caster.
This was achieved using PST adjustable strut rods which seem quite good.
Stock arms, adjustable strut rods and the alignment is almost identical from side to side. Tomorrow we set the toe and address a few other things.

 

[mopowers]

Glad you guys got it figured out. Sounds like the right arm just has something wrong with it. I'd be surprised if PST didn't want it back to see what's going on.

Is anything apparent when you lay the two on top of each other?

 

[340sFastback]

Sounds like Rich has to call PST? Ask for a return authorization?

 

[Kern Dog]

Glad you guys got it figured out. Sounds like the right arm just has something wrong with it. I'd be surprised if PST didn't want it back to see what's going on.

Is anything apparent when you lay the two on top of each other?

The only thing visible to the naked eye is that the barrels seem to not line up. This isn't as big of a problem with a stock arm because the rubber bushings can deform a little if needed. The bushings in the PST arms are some type of plastic or Delrin. I hoped to see something obvious, a smoking gun of sorts that would make it immediately clear. It may be a case of the "A" shape being uneven, almost like this:

Sounds like Rich has to call PST? Ask for a return authorization?

That is being taken under advisement and an answer is forthcoming.

 

[RustyRatRod]

It isn't the engineers. It's the bean-counters. I fight the money people over stupid **** they want to change to save a penny, every damned day.

That's probably very true.

 

[RustyRatRod]

Neither Rich or I in good conscience would feel right trying to sell these. The right side is just wrong. Maybe PST will accept these back, inspect and then decide if they will refund. That remains to be seen.
We put the stock arms back in. The upper ball joint zerk to bumper bolt was identical from left to right. It was 1/2” off with the PST arms.
Camber on the right was 3/4 degree NEGative with 3 5/8 degrees of POSitive caster. This is with the alignment cam bolts set almost exactly as they were with the PST arms aside from the front cam bolt being out of square in the PST arms.
The left side was aligned to rest at 3/4 degrees of NEGative camber and 3 1/4 degrees of caster.
This was achieved using PST adjustable strut rods which seem quite good.
Stock arms, adjustable strut rods and the alignment is almost identical from side to side. Tomorrow we set the toe and address a few other things.

So it sounds like yall narrowed it down to crappy made aftermarket control arms.

 

[Kern Dog]

I think so too. I’ve bought stuff from PST and been happy with it so this is probably an isolated issue. The adjustable strut rods Rich installed fit great and allowed us to increase caster to an acceptable amount.
Maybe the UCA was jigged and welded by a trainee or a guy working his last day!
We all want definitive evidence when trying to diagnose and fix a problem. For this issue, when the stock arms allowed nearly identical settings from side to side AND the aftermarket parts were miles apart, I dont see how the blame could be anywhere else.

 

[RustyRatRod]

I think so too. I’ve bought stuff from PST and been happy with it so this is probably an isolated issue. The adjustable strut rods Rich installed fit great and allowed us to increase caster to an acceptable amount.
Maybe the UCA was jigged and welded by a trainee or a guy working his last day!
We all want definitive evidence when trying to diagnose and fix a problem. For this issue, when the stock arms allowed nearly identical settings from side to side AND the aftermarket parts were miles apart, I dont see how the blame could be anywhere else.

Just be warned. Adjustable strut rods are not meant as a caster adjustment. All they are meant to do is get the LCA in the best position for good, smooth travel through its range of motion and that's all. You can end up putting the LCA bushings in a bind if you try and use the adjustable strut rods for additional caster adjustment. Just some friendly advice.

 

[Kern Dog]

I agree. Rich installed them at the same length as the stock ones but during alignment, we only cranked them in about 1/4" on each side. In theory, too much of that would distort the lower control arm bushing, leading to early failure.

 

[RBConvert]

So now what? Take PST arms off, put up for sale or send back, get something that fits?

I talked to Dan T at PST this morning, a very helpful gentleman. He right away confirmed that A body UCA's don't hit the bump stop. He also admitted that they have taken returns from customers related to the bump stop. I told him it wasn't an issue for me, but I suggested that maybe they can update their online notes. He liked the idea, but he could have been humoring me.
Regarding the construction of the RH UCA, obviously they can't diagnose over the phone, but he gave me an RMA #. He said they would first compare mine to one on the shelf for any obvious differences. If not, they ship it back to the manufacturer for testing.

 

[RBConvert]

We put the stock arms back in. The upper ball joint zerk to bumper bolt was identical from left to right. It was 1/2” off with the PST arms.
Camber on the right was 3/4 degree NEGative with 3 5/8 degrees of POSitive caster. This is with the alignment cam bolts set almost exactly as they were with the PST arms aside from the front cam bolt being out of square in the PST arms.
The left side was aligned to rest at 3/4 degrees of NEGative camber and 3 1/4 degrees of caster.
This was achieved using PST adjustable strut rods which seem quite good.
Stock arms, adjustable strut rods and the alignment is almost identical from side to side. Tomorrow we set the toe and address a few other things.

Stock arms with stock bushings. I thought I had installed Moog offset bushings when I rebuilt the suspension back in 2017.
Today we ended up right where I'd want the settings. With manual steering, 3°+ positive caster works for me, coupled with the <1° neg camber. At this point, I'm ready to part ways with the tubular arms. I don't need another 2 - 3° caster. It's probably a long shot now, since the arms have been installed, but I'm going to ask for a refund or store credit.
The car already handled great before the teardown, I was just getting greedy with the suspension changes. Swapping in the 1.03 T-bars (from .92) and adding the adjustable strut rods will make incremental improvements. For posterity, since 2017 I've installed new upper and lower ball joints, new upper and lower control arm bushings, new pitman and idler arms, tie rod ends, solid tie rod adjusters, and Bilstein shocks. The LCA's have been boxed and SFC's welded in. Firm Feel rebuilt the manual steering box.

 

[DionR]

Why would you buy those when we have the ultimate arms available?

What about bump stops for those arms?

 

[LST46]

I ran into the exact same problems with an older set of QA1’s that I installed on my Cuda about 12-13 years ago. Glad to see at least they’ve added a bump stop pad to theirs.