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Upper Ball Joint Advice Needed

66 Sat

Well-Known Member
Local time
10:29 AM
Apr 26, 2015
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My Upper Ball Joints both have split rubber seals on both sides of the car. About 5 years ago I'd bought the PST replacement UCAs that had the ball joints already installed and also the super front end kit so I had 2 spare upper ball joints. My plan was just to swap the rubber seals as the ball joints themselves seemed fine.
Starting on the driver's side I loosened the nut attaching the ball joint to the knuckle and the joint started to separate on its own - I thought it would be tight on the taper and need a whack with a hammer?

Q1. Is this normal for them to come apart so easily on recently installed ball joints (5 years) only driven in the dry?

While I was cleaning up the joint I noticed it was loose in the UCA! So much for being torqued to 100 lbs/ft - I could nearly undo it by hand! I haven't got the right socket, but I easily unscrewed it with my pipe wrench. I've ordered the 1 7/8" socket from Summit so will have to wait to re-install. I assumed they would have come fully torqued and I didn't check them at the time as I didn't have the right tool.

Q2. Should I try to get a new rubber seal for the ball joint that came mounted on the UCA or put the whole new ball joint in? I can't swap the seal only as I'd intended as they are a different shape and it won't fit properly but I reckon I can get a new rubber seal from a local supplier. The uninstalled ball joint looks to have even shallower threads that the one I took off and the seal is very tight and doesn't really fit over the ball joint although it might with a bit of grease/coaxing.

I'd do the new ball joint and do them right since you already have the parts. Wait on the socket and torque them in. Parts and materials today are not as good as originals for our cars. I've had gaskets, seals crack and go bad after a few years.
You're a lucky man. Thank God you check out your ride. as this should be a lesson to all of us always check and retorque don't assume it's been done right.
New quality uppers are still available.. Moog K772

You'll thank yourself later...

Hard to believe 37yrs after working for their parent company in the suspension department, quality still was not a the top of their priorities..
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When you get the replacement joints and the special socket that fits the head, pay attention to the studs. Make sure they are both the same in all dimensions. Your replacement ones most likely will come with flat washers. Those go under the castle nut to make sure the nut slots line up with a cotter pin hole. Don't skip the pins! The reason there may be washers in the package is because the manufactures decided to cut down on some of their inventory and use a stud from another application that can work when the washer gets used. I verified this some years ago at the SEMA show when I asked a rep from Proforged about this. He beat around the bush for a bit then finally fessed up. Since many of these joints get made overseas or from other companies and re-boxed[ stay away from chinesium junk], look at the studs. I have found that the tapered area can be different in length under the threads, the shoulder past the taper different in length to the ball, the interference fit threads on the main bodies different sizes[ just enough not to work at all] plus the threaded portion length. One car I worked on, 37 Chevy with Stang 2 suspension conversion which uses Mopar joints, those areas were all different from what I took off compared to the new stuff the car owner sourced. I ended up having to get some from NAPA and those were fine. Get this, there was an inch difference in length of the shoulder under the taper compared to what I ended up using. These were all stock replacement. Some of the circle track companies, Howe/QA1 and others have longer studs available for geometry improvements if you need them. To have two different units on one car can cause problems.
...and the washer can help with that, too.

Those, shallow, rounded threads on the body of the BJ should all be the same.
They do, however, make a "problem solver" BJ that IIRC Has sharper cutting threads.
Those threads are super easy to cross thread, and it is also super easy to crack the UCA, either all the way through, or just on the flange where it's threaded.
If the BJ doesn't thread on by hand at least a quarter turn and then go fairly easily another turn with a wrench.....stop- it's likely cross threading.
If the BJ threads all the way on and bottoms without getting tight.....stop- and very carefully examine your UCA- it might be cracked.
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Well after waiting 3+ weeks for the socket to arrive, I torqued up the driver's side ball joint, no issues.
Passenger side different story. Got the old ball joint out but of course the threads have stripped in the UCA. The new one went in ok and started to torque up but then stripped. Cue many swear words!
I'm going to spot weld it in and then get some tubular arms down the track which have a much deeper thread portion for the ball joint.


One more thing, with postage costs so high you'd think Summit would use a smaller box...
I've had to tack weld them before too. Just make sure the tacks are pretty good.... and the companies that ship a lot of stuff get pretty good discounts on shipping unlike the regular people like us. We get screwed over on prices to ship stuff....
Tack welding is fine. Rick Ehrenberg from Mopar Action magazine has suggested it numerous times. That guy is usually very careful regarding safety so if he is okay with it, I would be too.
Tack welding is fine. Rick Ehrenberg from Mopar Action magazine has suggested it numerous times. That guy is usually very careful regarding safety so if he is okay with it, I would be too.
Yup....and the softer metals are usually pretty safe to weld. The suspension parts are not hard and neither are the 'nuts' on top of the ball joints. Just need more than a small tack but don't go nuts with it. I usually lay down a 1/4" long with a well penetrating bead on all 4 flats. Never had a problem and are still able to to take a death wheel to them to cut the welds when they need to be replaced. I've seen some where they were welded solid lol. Not even gonna try to remove that kind of stuff. Just get another UCA!
I had to tack weld one UCA ball joint on my GTX. It's held up fine for 6 years of running around.
Well after 26 days of being off the road it's all back together and running sweet. Took it for a test drive this afternoon, it was good to be back behind the wheel.

Good looking car.

Factory gold works well on that body.
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