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I'm trying to diagnose a situation, and asking for help from my fellow SRFers...

When doing a bearing check recently, my RR wheel had a little more movement (wobble) than I like. Thinking initially it was just the bearing, I swapped that out and felt marginal improvement, but not really what I expected. As I played with it more, I found I couldn't feel the wobble when shaking the tire horizontally (hands at 3:00 & 9:00), but did feel it when holding the tire at 6 & 12. I put in a brand new LBJ pin as of the start of this year, and just replaced the LBJ rod end with a new one to make sure those shouldn't be the cause.

I have a new hub and upright, and the differences in diameter between new and what's on the car can be measured in 10ths of a mm. That along with the fact that I only get wobble in a vertical shake and not horizontal, my inclination is that it is not a worn hub/upright issue, but that could still be a possibility. The lower control arm does not appear to have any movement when I unbolt it from the LBJ pin and push/pull on that horizontally. The other thing I'm thinking is perhaps the UBJ has some excessive play in it.

I'm asking for your thoughts on likely causes. Thanks for your help gang!

Dan,

Brian Parmelee, TJ's mechanic for years, taught me that if the wheel moves (or clicks) vertically, it is usually the bearing. Given that you have just put in a new bearing, the first thing I would try is tightening the axle nut with a nice long breaker bar to compress the bearing. If that does not help, the second thing I would try (with two people) is holding/touching each suspension point with your hand/fingers to see if you can feel movement while the other person shakes the wheel. You can localize the movement that way to specific parts and replace any offending parts (another trick from Brian).

DaveP

Thanks Dave. What you suggest is what I've checked (albeit just by myself), and I can't find anything else that's moving. What's weird to me is I get wobble only in a vertical shake and not in a horizontal shake. I would have thought that a bearing should wobble in more than one direction...

I received a suggestion offline - will try that tonight and post results...

Dan: Check the upper ball joint. It's easy. Simply lift the wheel straight up by holding it with your finger tips (two hands) under the uppermost inside edge of the wheel (under the bead flange). If you still see that play, almost for sure it's a worn out upper ball joint. Easy fix. (Same thing happened to me.)

Thanks for the tip Bob. I wasn't sure how to isolate the UBJ to tell for certain, so I'll try that tonight as well!

Also rocker arm bushings and sometimes shock balls.

I just had a similar issue on the front and discovered I had not fully tightened the bolt that holds the lower pin.

Thanks everybody for the input. I swapped out the UBJ and that improved it a good bit. Also took a tiny amount of material off one bearing race and that seems to have allowed the bearing to seat much better. It feels much better now - we'll see how it goes this weekend!