Lower ball joints

chris_kucia · December 15, 2006

Not sure if this will apply to everyone, but here's a warning...

Replaced one of my hubs last night. I was surprised to find that when I lifted the wrench to break loose one of the hub retaining bolts, the entire knuckle lifted up off the ball joint, and not just a little. My lower ball joint is severely worn.

Reason I'm posting, is I had very little "looseness" in the steering and no noise, and when the truck is in the air, if you grab the wheel at "12 and 6", there's no rocking.

If you know what to look for, its easy to find the worn component, but I've been playing around with cars as a hobby for the better part of 20 years and I missed this - I did a quick suspension check before buying the hubs and everything felt tight. If I hadn't replaced my hub (and I did that because the ABS light came on), I might not have found the bad joint until it was too late.

Maybe I just have a weirdly worn joint, but this kind of scared me. I thought about taking a cab to work today. As it is, I'm staying off the freeway and taking it very easy until I can get this joint fixed.

FYI...

95Sierra2500 · December 15, 2006

while the old '12 and 6' thing can find a bad ball joint, it's really more for wheel bearings. A better way to check for a bad ball joint is to get the tire 1-2" off the ground (closer to 1) and put a pry bar under it, then pry up and down on the tire. This will check your ball joints (at least the lowers) for vertical play. The reason this works is because you have force on the lower control arms that points towards the ground, and by prying UP you create a force in the other direction. If there is slack in the ball joint, it'll show.

az'03Silverado · December 15, 2006

Is it difficult to replace? Is it OK to use the bolt-in kind or is riveting better?

chris_kucia · December 16, 2006

Is it difficult to replace?
<{POST_SNAPBACK}>

After 140k, in a word, yes. Its a PITA.

I've been working on it for two days. Can't locate any tool like the one the service manual (unless I go order it from Kent-Moore) to get the tapered stud of the joint out of the knuckle. I've hit it with a sledge, tried pickle forks, soaked it in penetrating oil and broken two gear pullers trying to get it out.

The way the suspension is designed (which is probably a good thing) the ball joint is squeezed constantly between the bottom of the lower control arm and the top of the knuckle (which "L"s under the control arm). Problem is, there's nothing on the truck to help keep the knuckle in place, so hitting the stud doesn't really do squat - it just pushes the ball joint tighter into the control arm, but doesn't put any force on the knuckle.

Once I get it off the knuckle, the ball joint is pressed into the control arm, which I do have a tool to remove while on the truck (GM wants you to take the control arm off the truck, which involves removing the torsion bars, etc.)

chris_kucia · December 16, 2006

while the old '12 and 6' thing can find a bad ball joint, it's really more for wheel bearings. A better way to check for a bad ball joint is to get the tire 1-2" off the ground (closer to 1) and put a pry bar under it, then pry up and down on the tire. This will check your ball joints (at least the lowers) for vertical play. The reason this works is because you have force on the lower control arms that points towards the ground, and by prying UP you create a force in the other direction. If there is slack in the ball joint, it'll show.

<{POST_SNAPBACK}>

Thanks. I'll keep that in mind for future reference. I try not to make the same mistakes twice

95Sierra2500 · December 16, 2006

Is it difficult to replace?
<{POST_SNAPBACK}>

After 140k, in a word, yes. Its a PITA.

I've been working on it for two days. Can't locate any tool like the one the service manual (unless I go order it from Kent-Moore) to get the tapered stud of the joint out of the knuckle. I've hit it with a sledge, tried pickle forks, soaked it in penetrating oil and broken two gear pullers trying to get it out.

The way the suspension is designed (which is probably a good thing) the ball joint is squeezed constantly between the bottom of the lower control arm and the top of the knuckle (which "L"s under the control arm). Problem is, there's nothing on the truck to help keep the knuckle in place, so hitting the stud doesn't really do squat - it just pushes the ball joint tighter into the control arm, but doesn't put any force on the knuckle.

Once I get it off the knuckle, the ball joint is pressed into the control arm, which I do have a tool to remove while on the truck (GM wants you to take the control arm off the truck, which involves removing the torsion bars, etc.)

<{POST_SNAPBACK}>

You may want to try putting a jack under the control arm and jacking up a bit if you haven't already tried that. If I'm guessing correctly, your problem is that the ball joint stud points DOWN, in which case hitting the stud or simply using a pickle fork would be difficult. LIFTING the control arm up would give you all the slack you would need to separate the stud from the knuckle (I think).