Upper Ball Joint Question

[70SwingerGuy]

I have a 70 Swinger, 340 4 spd and am unsure as to what size upper ball joint to get. Ive been looking around and have found both small and large size joints, and application descriptions can be confusing depending on supplier. And one supplier doesnt even list if its small or large, just that it will fit my car.
So what is the correct ubj for my car? I cant go out to the garage and measure cause its in the bodyshop right now, and Id like to take advantage of a boxing week special if I can.
Thanks for any help FABO!

 

[RustyRatRod]

As long as it has the original style upper control arms, small.

 

[70SwingerGuy]

As long as it has the original style upper control arms, small.

Wow, someone else is up late! Thanks Rusty

 

[RustyRatRod]

Wow, someone else is up late! Thanks Rusty

Sho nuff.

 

[1WildRT]

Yup, small until 73 And in 73-76 if it has 9" drum brakes it still uses the small joint..

Basically if it use the 5x4 lug pattern it uses the small ball joint...

if it use the 5x4.5 lug pattern it uses the larger ball joint...

 

[70SwingerGuy]

@1WildRT And thank you as well

 

[72bluNblu]

Yup, small until 73 And in 73-76 if it has 9" drum brakes it still uses the small joint..

Basically if it use the 5x4 lug pattern it uses the small ball joint...

if it use the 5x4.5 lug pattern it uses the larger ball joint...

No.

All UCA's 73+ are the large ball joint style regardless of bolt pattern. The spindles and the brakes changed. 9" drums in the front also went away. Only the first few months of '73 production were different, by November '72 the changeover to the new 73+ drums was finished. So, large ball joints, small bolt pattern 10" drums.
https://www.hamtramck-historical.com/images/TSBs/1973/05-03-73C page1.jpg

I have a 70 Swinger, 340 4 spd and am unsure as to what size upper ball joint to get. Ive been looking around and have found both small and large size joints, and application descriptions can be confusing depending on supplier. And one supplier doesnt even list if its small or large, just that it will fit my car.
So what is the correct ubj for my car? I cant go out to the garage and measure cause its in the bodyshop right now, and Id like to take advantage of a boxing week special if I can.
Thanks for any help FABO!

Like RRR said, if it has the factory UCA's and brakes it should be the smaller upper ball joint. But a lot can happen in 55 years.

 

[RustyRatRod]

But a lot can happen in 55 years.

You got dat chit right!

 

[1WildRT]

No.

All UCA's 73+ are the large ball joint style regardless of bolt pattern. The spindles and the brakes changed. 9" drums in the front also went away. Only the first few months of '73 production were different, by November '72 the changeover to the new 73+ drums was finished. So, large ball joints, small bolt pattern 10" drums.
https://www.hamtramck-historical.com/images/TSBs/1973/05-03-73C page1.jpg

Like RRR said, if it has the factory UCA's and brakes it should be the smaller upper ball joint. But a lot can happen in 55 years.

See what happens when you trust a parts listing.... I've dealt with a apparently early 73 that had the small ball joints...

 

[Ozyduster]

Pretty sure 73+ is bigger ball joint. If removing them easiest to do it on the car and usually need a big breaker bar as tight as all hell. My threads crapped themselves when removing them so arms are for the bin. I ended up buying new arms with balljoints already fitted as got a second set of original arms and same thing happened.

 

[cudamark]

Yup, small until 73 And in 73-76 if it has 9" drum brakes it still uses the small joint..

Basically if it use the 5x4 lug pattern it uses the small ball joint...

if it use the 5x4.5 lug pattern it uses the larger ball joint...

Not true. ALL '73-6 A-bodies use the large upper ball joint regardless of which brakes it has.

 

[RustyRatRod]

Not true. ALL '73-6 A-bodies use the large upper ball joint regardless of which brakes it has.

Nope. Some early 73 got the small ball joints. I've seen one with my own good eyeball. I forget which month it was, but it was before January of 73 and was a 73 model Scamp. I know cause it was mine. I THINK it was an October build date, but I honestly cannot remember. That's been a long time ago. But some really early 73 models did come through with the small ball joint.

 

[72bluNblu]

Not true. ALL '73-6 A-bodies use the large upper ball joint regardless of which brakes it has.

That is most likely true from November '72 on. From August '72 to November '72 (which is all '73 model year production) it's not a guarantee, the TSB I posted above lists the final crossover date of November 1, 1972.

My guess is up until November '72 there was probably some SBJ stuff going out as previous stock was used up, as we all know Ma Mopar had a tendency to do when production changes were made. So the closer to the TSB date the less likely anything would have left with SBJ. Show me a 9" drum spindle that takes a large upper ball joint and I might consider changing my mind, but I'd say that everything after November 1 '72 is large ball joint regardless of disk/drum brakes, but prior to that a drum car might still have a chance of being SBJ.

See what happens when you trust a parts listing.... I've dealt with a apparently early 73 that had the small ball joints...

Nope. Some early 73 got the small ball joints. I've seen one with my own good eyeball. I forget which month it was, but it was before January of 73 and was a 73 model Scamp. I know cause it was mine. I THINK it was an October build date, but I honestly cannot remember. That's been a long time ago. But some really early 73 models did come through with the small ball joint.

Early '73 I'd put into the "who knows" category. If you weren't the original owner who knows what happened before you got it. But for that matter, who knows what happened at the factory before the TSB documentation took effect either. After the first few months of production for the '73 model year though I'd say '73+ would probably be LBJ from the factory at least.

 

[RustyRatRod]

That is most likely true from November '72 on. From August '72 to November '72 (which is all '73 model year production) it's not a guarantee, the TSB I posted above lists the final crossover date of November 1, 1972.

My guess is up until November '72 there was probably some SBJ stuff going out as previous stock was used up, as we all know Ma Mopar had a tendency to do when production changes were made. So the closer to the TSB date the less likely anything would have left with SBJ. Show me a 9" drum spindle that takes a large upper ball joint and I might consider changing my mind, but I'd say that everything after November 1 '72 is large ball joint regardless of disk/drum brakes, but prior to that a drum car might still have a chance of being SBJ.




Early '73 I'd put into the "who knows" category. If you weren't the original owner who knows what happened before you got it. But for that matter, who knows what happened at the factory before the TSB documentation took effect either. After the first few months of production for the '73 model year though I'd say '73+ would probably be LBJ from the factory at least.

It had a 7.25 under it when I got it, along with 9" brakes all around. I did put an 8.75 under the car and sold it shortly after. I've always wished I'd kept that car. It was really solid. The 73 Valiant based cars had my favorite front end and grille.

 

[cudamark]

I had two of September built '72 models. Both were 9" front drum with the large ball joint. The spindle is the same one as the 10" drum brake, so, they both use the A2 and A17 bearings. If you look in the factory and aftermarket parts books, only one control arm, spindle, and ball joint is listed for a '73-up A-body model. I don't know what to say on the one you had. Maybe it had been changed for some reason? I know those early 9" hub and drums were a tough on to find, so, maybe they reverted back to something that would bolt on. Strange things can happen over these last 50-60 years.

 

[72bluNblu]

I had two of September built '72 models. Both were 9" front drum with the large ball joint. The spindle is the same one as the 10" drum brake, so, they both use the A2 and A17 bearings. If you look in the factory and aftermarket parts books, only one control arm, spindle, and ball joint is listed for a '73-up A-body model. I don't know what to say on the one you had. Maybe it had been changed for some reason? I know those early 9" hub and drums were a tough on to find, so, maybe they reverted back to something that would bolt on. Strange things can happen over these last 50-60 years.

Yeah, I've heard that argument before and unless you can produce a large bearing 9" drum hub I'm putting that in one unicorn territory. It makes zero sense for the factory to design a new 9" drum hub and phase it out a couple months later.

Not saying it couldn't have happened, but without evidence, sorry, I'm not buying it. Show me the magical 3 month only 9" large bearing drum hubs.

 

[cudamark]

Mine were both 198/904 column shift plain Jane animals. No options at all. They were rubber mat cars, so, the floors were rusted out. That's how I got them as parts cars. They both had original paint and interiors, so, pretty much untouched. I got them in 1982 so, unlikely anything had been changed on them....and they both looked it. I had orders to fill from individuals and brake shops for those hub and drums as they had been discontinued by Mother Mopar, and the aftermarket didn't have them. I believe the "crossover" as 72bluNblu mentioned was when they discontinued the 9" brakes altogether and only made the 10" brakes from then on. Like I said, look in the factory parts book. There is no before and after date for any of those spindles, ball joints, or control arms.

 

[cudamark]

The part number for that hub and drum assembly is 3699574. The 70-2 hub and drum is 3580533.

 

[cudamark]

Oh, and I sold the upper control arms with disc brake changeovers because they had the larger ball joint.

 

[RustyRatRod]

I had two of September built '72 models. Both were 9" front drum with the large ball joint. The spindle is the same one as the 10" drum brake, so, they both use the A2 and A17 bearings. If you look in the factory and aftermarket parts books, only one control arm, spindle, and ball joint is listed for a '73-up A-body model. I don't know what to say on the one you had. Maybe it had been changed for some reason? I know those early 9" hub and drums were a tough on to find, so, maybe they reverted back to something that would bolt on. Strange things can happen over these last 50-60 years.

Absolutely so! ...and I don't discount mine COULD have been changed at some point, bit I firmly believe it was original.

 

[cudamark]

Later on in the mid 90's I had a customer do just that. At that point we couldn't come up with the correct hub and drum to fit his early '73. He didn't have the money to do a disc C/O, so, I sold him the earlier spindle, upper control arm, brakes and all so he could just get it back on the road.