russell-t

I need to replace the left lower ball joint on my 63 f-85.

My mechanic says that because the lower ball joint in question has

tack welds on it, the lower control arm is damaged and I need to replace it.

Got a replacement from junkyard, the ball joint on it is tack welded too.

Is this something that was done by repairmen to secure press-in ball joints?

It seems that I have just bought another lower control arm for nothing.

Does anybody know about this stuff?

Oldsmaniac

I would think the GM did not tach weld. It is possible the new ball joints were not true to size and needed the welds or perhaps the arm was worn or damaged upon removal of ball joint. Perhaps someone who knows will post an answer.

J-(Chicago)

I have seen a few cars with factory tack welds on the door hinges, so I'd think it is possible.

Allan R

It seems awfully coincidental that both LCA's have tack welds. How does the rest of the CA look? If it's fine otherwise, I'd be inclined to grind the tack welds and press the old ball joints out. Can't hurt to practice on one and see how it comes out. Tack welds are not installed as permanent welds, they are just there to hold a piece of metal in place till a final weld is done.

FWIW I checked the 63 f85 CSM for lower ball joint removal. There is NO mention anywhere of needing tack welds. Someone down your way is going crazy with their welder by the sounds of it.

russell-t

Drilled and ground out the tack welds on the junkyard control arm,and

removed the ball joint with a hammer and a large socket.Didn't take much

effort to remove it. New ball joint seems as though it will fit tightly with a

press in.Took it to my mechanic,he says he will install the control arm with

new bushings,upper and lower ball joints that I got from Kanter.

Mechanic says he is unfamiliar with this tack welding on ball joints,and

believes that it is something done on classic cars because of scarcity of

replacement parts. I can go with that.

Regarding reply saying it must be something going on in my local

area, I say that it has to be something mechanics do all over the country.

The reason I say that is the car came from Maryland,and the replacement

control arm I bought came from a junkyard in Oklahoma!

All this being said I suppose I will soon have a lower control arm to

throw up in the rafters with the rest of my Cutlass parts.

Thanks to all of you who read and replied to my post.Your input is

important to all of us who own these OLD cars.

russell-t

Allan R

So does that mean you're going to have the new ball joint tack welded, or just leave as a press in fitment? Didn't realize the car and donor part were so far apart geographically, that's why I suggested it may have been a local thing. Can you post a pic of the LCA that you have extra showing the tack welds - just for us curious types?

russell-t

My mechanic says that may have to tack weld the ball joints after

installation if he feels that they need it. They will be the last ball joints

ever installed in the car while I own it. So tack welding them in place is

not a problem for me.

I've loaded pictures of the welds on the left ball joint,and a picture of the

unwelded right side to show what my problem was. I drilled and ground

out the tack welds on the junkyard part already.Took about 20
minutes.Fairly easy.

The first picture is of the welded left lower ball joint. The other is

the right side.

MDchanic

Tack welding replacement ball joints was a common practice.
They often don't fit quite so tightly the second time around, and if left alone, the infinitesimal movement that can occur with thousands or millions of tiny impacts can enlarge the holes, and cause meaningful looseness.
A little tack weld can prevent that initial unmeasurable movement, and prevent the joint from loosening later.

Also, in a world in which few cars went beyond 100,000 miles, and most ball joints lasted more than 60,000 miles, nobody ever worried about how they would get that second set of ball joints off forty years in the future.

- Eric

Allan R

Ah hah! The good Dr has spoken. Knew we'd find an answer somewhere. So how does this compare to replacing ball joints on my 72? Don't tell me I need to consider doing this too?

OLDSRALLYE350

Any time we replace ball joints in a steel control arm where we feel that the fitment is not as tight as factory we spot weld them to prevent any movement . We spotted in lowers on a 94 chevy van last month.

Allan R

Ok, here's a dumb question. Why did GM have riveted top ball joints and press fit lowers? Wouldn't it have made more sense to have both riveted so that when replacement was necessary you could do the same procedure on both upper/lower? Then you wouldn't have any issues with tack welding?

russell-t

MDchanic....Thank you! Somehow I knew that this was something that shops did

to ball joints to prevent movement. My mechanic will see a printed version of your

reply soon.

MDchanic

Because the forces in play in the upper and lower ball joints are very different.

The lower ball joints each carry over a quarter of the weight of the car at all times.
The upper frame perches sit on top of the springs, the bottoms of the springs sit on top of the lower control arms, the ends of the lower control arms sit on the ridges of the lower ball joints, the spindles of the lower ball joints are bolted to the steering knuckles, and the steering knuckles are attached to the wheels, so all of the weight is on those ball joints, pushing and holding them into their holes in the control arms.

The upper ball joints carry no weight, and serve only to locate the tops of the spindles.
Essentially all of the forces on them are lateral.

So, the uppers need to be held in place, while the lowers stay in place on their own, so long as they are tight in their holes.

- Eric

Highwayman

It because design engineers are weird folks that live in an altered universe with no connections to the world as we know it. But mostly it's what Eric said about the load factors. That's why lower joints often wear out at twice the rate of upper ones.

cheven

Tacking is fine, some new cars today (crown vic) offer "oversize" bj's because of arm wear. If you are not bustin a nut trying to push them out, I'd give a tack, its not a bad thing ....but too much of a good thing IS bad, so don't weld them like you're running a bead on the Queen Mary hull. Of course make sure all the grease and goo is gone otherwise you're not "helping"