Control Arm questions

ebk · November 2, 2017

Thanks again for all the help and feedback. Here are my thoughts after doing it. It's one of those jobs that takes you twice as long the first time you do it. I ended up keeping the bearing hub on the knuckle to save some time. It was a bit heavy, but I didn't need to mess with taking the hub off. You were right about not needing a puller. The hub comes right off. I wasted a lot of time trying to get the first ball joint off without cutting the boot. I was hammered the crap out of it, expecting it to pop off. I was whaling on it with a 3lb hammer with no luck. I finally used the pickle fork with the air hammer and it came off in a few seconds. Used the air hammer to back off the tabs securing the lower joint. The c-arm was a pain, and I could have used a extra hand to keep it together. I had to get the extender kit to for the additional sized cups. The ones in the starter kit wouldn't have done it. I put the new ones in and it took some effort to get them on. The upper one started out a little crooked and finally straightened out. I have a 3 foot 1/2" breaker bar and i was putting every ounce of energy into it to get it to move. I am kind of surprised that the c-arm didn't give way. Also, I started out with a cheap air hammer that had a short stroke, not enough power, and it didn't work. I had to get a second one that had enough juice. This was one job where the right tools are a must. Thanks again!!

Chubbs878 · November 3, 2017

you are the man. good work. how's she driving now? I bet tighter than a diamond up a cat's a$$, assuming the steering linkage is within reason...

ebk · November 3, 2017

Driving pretty well. Alignment seems the same, but the steering is definitely tighter. I ended up replacing the upper one while I was at it. Perhaps that helped to keep things relatively lined up. Going to replace the idler arm next, and I will get it aligned after that. You were spot on w your advice, btw, e.g., axle, torsion bar, etc.. Probably would not have moved ahead without it. Funny, it looks so straightforward when it's on one of the videos on a lift with ball joints popping out of the knuckle with a few hammer blows. I guess they edit out the other 50 swings. I really felt my age on this one, but I am really glad I did it. Thanks again!

Chubbs878 · November 4, 2017

Nice that it all worked out. I forgot to mention that in some instances, the spindle also needs replacing along with the ball joints. You never hear about it or read online because 99% of your DIYers don't know what's going on. I figured this out on a different make SUV when I replaced the ball joints and after torquing the ball stud nuts to spec, the spindle was too tight for free & unrestricted movement/rotation. I searched threads via Google & forums but never found anything stating the root cause or fix. There were threads discussing the same problem but these fools' response was to back off the nuts enough to allow movement again, which is loose by anyone's standards. Some members opinions described the circumstances as "normal" & "requires break-in"

this is misinforming and terrible advice as suggesting it's OK to reduce torque specs. Just dangerous & people searching the topic will find those threads & repeat the same mistake. Since then I have taken it upon myself to post relevant info especially if it helps DIYers perform a complete repair and not place lives in danger.

The cause of a tight spindle with ball joint replacement is obviously the bores wear out in the spindle/knuckle & when placing the original spindle on new ball joint studs, the tolerance is great enough that the spindle now seats higher up the stud taper than originall designed and the torquing of fastener locks the spindle up. When this happens just throw the spindle away... In the garbage, and go pick up 2 others from a junk yard or just buy 1 brand new. This is the only fix and it's important always follow torque specs since in a case exactly like this, the torque specification brings larger problems into focus.

This is is a public message, not directed to 'ebk' unless this applies to your repair, although I'm sure you'd have made mention of such.

And yes, in my investigations I measured both orig ball stud & replacement ball studs with micrometer to verify the issue wasn't with the new ball joint stud manufacture. A used spindle from the same make truck with good ball joints worked with my replacement BJs where the old/original spindle would not. And I wasn't even experiencing excessive play where the spindle was allowed to move/bounce. I actually replaced due to a torn boot on the BJ as preventative maint when I had some extra time & then encountered this ordeal. I called service depts & mechanics about this & not 1 person advised I look at the spindle. Took me a week to figure the whole thing out as this truck had a built in adjuster on bot of spindle for lower ball joint so I had started with that and wasted a bunch of time. If you ever find an adjuster where the lower BJ seats, look for manufacturer info in regard to its purpose and specs before spending any time on it.

Since the the make of truck we are discussing takes a cotter pin & castle nut, you prob have 3 out 4 guys backing OFF the nut to get a cotter pin to line up. Always use a torque wrench set to prescribed specs and when reaching said spec NEVER back off a nut to align a cotter pin unless it's a **** HAIR, no more. If you have to loosen a tie rod or ball joint nut to get the pin to line up, again, replace the spindle. The taper of bore on the original spindle is worn out of spec so proceeding with the install is discouraged & bad practice.

ebk · November 5, 2017

Thanks for the tip. Interesting about the taper hole getting bigger. I guess if the stud spins inside the taper, when it is removed or installed, it finally loosens up. I bet a lot of DIYs and even shops don't bother securing the hex on the end of the stud. They probably just use an impact wrench on it and let it spin inside until it grabs. This was the first replacement on my Yukon so the new stud seated properly and the knuckle had good movement. Not good that some are suggesting to back off the nut until it moves freely. Sounds pretty dangerous.