Changebout Upper Control Arms?

Duster360LA · Wednesday at 10:19 AM

I've pretty much wrapped up my 74 Duster restomod project, but in going through and greasing my fittings I noticed the circular metal plate that the grease ripple goes in to on the passenger side upper control arm bulges up slightly and grease comes out around the edges. The UCA assemblies were rebuilt by the previous owner and never saw any driving.
While the easy fix would just be to replace it, I'm wondering what the benefits would be of getting tubular UCAs?
For background, my Duster is running a mildly built 5.9 Magnum (350 HP) with a 5-speed Tremec. The front end has all new performance bushings, hotchkiss shocks, Kanter sway bar, Borgson high ration power steering box, Flaming River column and new Pittman and idler arms. I also have a new set of 1.03 torsion bars coming in to put on.
I plan to take the car on 1,000 mile plus trips around the country visiting shows and swap meets. Won't see the track or do any road rallies.
Is it worth the cost to go to tubular UCAs?

go-fish · Wednesday at 11:32 AM

I like Firm Feel and SPC Gen I or II. With your set up I would, at the very least, use Moog offset bushings. There is more to be had beyond what the bushings can give you though.
Use the search function to look up reviews on specific UCA’s you’re interested in and follow the builds that are using them in spirited driving. I’ve never seen someone say it wasn’t worth using geometry corrected arms.

72bluNblu · Wednesday at 12:08 PM

Duster360LA said:
I've pretty much wrapped up my 74 Duster restomod project, but in going through and greasing my fittings I noticed the circular metal plate that the grease ripple goes in to on the passenger side upper control arm bulges up slightly and grease comes out around the edges. The UCA assemblies were rebuilt by the previous owner and never saw any driving.
While the easy fix would just be to replace it, I'm wondering what the benefits would be of getting tubular UCAs?
For background, my Duster is running a mildly built 5.9 Magnum (350 HP) with a 5-speed Tremec. The front end has all new performance bushings, hotchkiss shocks, Kanter sway bar, Borgson high ration power steering box, Flaming River column and new Pittman and idler arms. I also have a new set of 1.03 torsion bars coming in to put on.
I plan to take the car on 1,000 mile plus trips around the country visiting shows and swap meets. Won't see the track or do any road rallies.
Is it worth the cost to go to tubular UCAs?

It really depends on the set up that you have now, which doesn't sound entirely stock at least by your description. Can you post a picture of what you have now?

Beyond that, as go-fish pointed out if you have the factory arms you'll at least need offset UCA bushings in order to get decent caster numbers for running radial tires. Based on the description of your build though it would probably benefit you to have more caster than most people can get with the factory UCA's and offset bushings. Adding caster to the alignment settings really makes driving these cars a nicer experience when you're running more modern radial tires, and is absolutely necessary if you're going to larger diameter wheels and wider tires up front.

Duster360LA · Wednesday at 12:36 PM

Thanks - that info helps. I am running 215/65 R15 radials on the front, but I had 225/70 R15 TA radials on it when it was aligned a couple months ago. Handles pretty well at this point, but if I am going to benefit from a switchover I would rather do it now.
Ive attached a few photos of the current setup.

go-fish · Wednesday at 1:26 PM

Looks very similar to my 73 Duster.
1.03” bars, Helwig sway bar, Fox shocks, Borgeson, … but I have Gen I SPC arms and QA1 lowers. 225/60-15, Cordoba brakes.
I daily mine most of the year. Very sporty handling, just a touch harsher ride but very much worth it. I would call this like an optimized OEM suspension. You are very close to it so I would recommend getting the UCA’s you really want.

72bluNblu · Wednesday at 2:13 PM

Is this the issue you're concerned about?

The zerk fitting just needs to be tightened. If the zerk threads in the upper ball joint are stripped you might have to use a zerk with a larger fitting on it to get it to seal again. If the ball joint is good then the zerk fitting isn't a huge concern as long as the ball joint has been greased appropriately.

Do you recall what the alignment specs were when you had it aligned? 215's or even 225's aren't wide enough to require a whole ton of caster. You do want a few degrees of positive caster, but you don't need like 6°+ like if you were running 275's up front like I do.

Which is not to say you can't switch out your UCA's or that it wouldn't be an improvement, but you certainly don't need to replace the whole UCA just because of a bad zerk fitting. A zerk with larger threads, or at worst a new ball joint, would solve the issue without changing the UCA's. Now if you want to change the UCA's and get more caster than you had before (whatever that is), feel free to carry on!

Oldmanmopar · 2025-12-04T07:37:36-0600

Looks like you put the lower control arm bump stops where the uppers would go.

Duster360LA · 2025-12-04T11:57:07-0600

Thanks, I'll check the bumpers. I believe there is a black lower bumper in place. The original owner installed those.
And 72blu - I took a photo of the good UCA side, so I went back and took a shot of the problem side (below). I have pretty much decided to get QA1 upper control arms.

CudaJason · 2025-12-04T12:45:30-0600

yeah that does not look right. Id say it may be a cheap import replacement ball joint, definitely not assembled right.

72bluNblu · 2025-12-04T12:56:37-0600

Duster360LA said:
Thanks, I'll check the bumpers. I believe there is a black lower bumper in place. The original owner installed those.
And 72blu - I took a photo of the good UCA side, so I went back and took a shot of the problem side (below). I have pretty much decided to get QA1 upper control arms.

View attachment 1716485632

Oh! Yeah, that ball joint is shot. The "cap" on it shouldn't have much to do with the operation of the rest of it, but it's gonna leak if nothing else. Wouldn't give me confidence on the rest of the assembly though.

At the minimum you need to replace that ball joint, although that doesn't require upgrading to tubular UCA's.

Um, QA1 has had some manufacturing issues with the passenger side UCA's lately. FirmFeel also sells tubular UCA's at about the same price point for the large ball joint UCA's Firmfeel Mopar Suspension and Steering

I'm sure QA1 will sort out their issue, but there have been a couple members here that have sent back QA1 UCA's recently. QA1 has replaced them at no charge as far as I know, just FYI.

Detroit Iron · 2025-12-04T15:13:34-0600

Same thing happened to me. Documented here:

Changebout Upper Control Arms?

Duster360LA

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go-fish

FABO Gold Member

72bluNblu

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Duster360LA

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go-fish

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72bluNblu

FABO Gold Member

Oldmanmopar

Going left turning right

Duster360LA

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CudaJason

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72bluNblu

FABO Gold Member

Detroit Iron

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