How can you tell UCA is bad?
 

My left Upper control arm was squeaking and clunking at every hole and bump so I changed it. However, the old one does not seem worn out at all! I tried moving it by hand and it felt tight.
Should I be able to see easily that the bad UCA's ball joint is loose?
I'm only asking because I wonder if there was something else that was making the noise.
(I still have the old ball joint / UCA, so whatever you guys recommend I do to check it, I will do it. Really curious about this!)

you probably can't put as much force on it by hand as a 4000lb car can :D
did replacing it solve the squeaking issue?

You're probably right about 4000lb Lexus :) It just sounded so bad, I thought, surely if I jiggle the ball joint by hand, it will feel loose.
I drove it around the block, and then over the bumps and holes and - nothing. Not a peep and no squeaks. I guess that means I nailed it?

As I've come to see with this car, it seems like a lot of suspension issues outside of the strut bar aren't clearly obvious when they "break". It's more-so that things just get tired and start to make noise because nothing is invulnerable to time.

Still, I'd rather have that than a axle breaking or bolts shearing like you see in other cars when suspension breaks.

If the ball joint was bad you should be able to move it by hand round and round. But what you probably heard clunking was the UCA bushings. Those will clang like metal to metal sound or squeak when they start to deteriorate. If you don't hear the same noises now after changing the UCA then I would sure put money on it, that was your problem.

Thanks deanshark! I always thought that ball joint would go first.

For what it's worth, I ran in to a similar issue with my 99 but it was the lower control arm on the passenger side.

About 2 years after I replaced my strut rod bushings I started to hear clunking and knocking again when going up my driveway or over speed bumps. I knew it couldn't be the strut rods bad again being only 2 years later; furthermore this clunking was "different" than the strut rod clunking I heard prior. (Hard to describe the differences over text...)
Turns out it was the bushing on the lower control arm. Jacking up the car and visually inspecting the issue wasn't glaringly obvious, but I saw some movement in that area when applying force to the wheel/tire by hand.
Once the control arm was removed though it was absolutely blatant that the bushing was toast. I replaced the ball joint as well for good measure. I could move the original ball joint by hand, but the grease boot and everything was still in pretty good shape.

You don't want to let the ball joints just "GO". I had 2 ball joint failures. One each on my 93 (upper) and 94 (lower). Luckily on the 94 I was only going about 2 MPH pulling in a driveway when it just broke in half. (10 minutes earlier I was at about 95 MPH on the highway) The 93 was about 20 MPH taking a turn when it let go and pushed the tire right through the inner fenderwell and into the engine bay. Not a pretty sight.
You can check the bushings on the UCA you removed by putting a screwdriver through the bolt hole on the bushing and try moving it back and forth.

I had my lower balljoints go bad when I bought my 97' w/ 253k, then about 10k later the inner LCA bushing on the driver side went. Never experienced a Strut rod bushing since both previous owners had done that job for me already before buying the cars, 97' and 99'

I made a video of my LCA issue and posted it on here if you want to see if that noise is similar to yours

Wow, I thought that could never happen on an LS, but it's good to know that our cars are not invincible. Were those OEM UCAs and were there any signs of UCAs going bad?

On my 94 it was the lower ball joint that went. (I'll edit the other post)
Yes they were OEM. Still original, both close to 200k. But now on my 94, same side, the UCA bushings are bad and getting worse. The clanging is starting to get louder. I've had the new parts (not OEM) for 6 months but cuz of my neck surgery I cant put them in yet. I only drive 5 miles a day so I aint worried, yet. Now I got a bad wheel bearing in the back. Looking into an LS460 in a few months anyway so just hoping it lasts another 3-6 months and then it will be someone else's problem to fix.
The only sign of the bushings going bad was the clanging. On the ball joints, both upper and lower, the sign was that when I took a corner, the steering wheel didn't come back to center on it's own, I had to physically turn the wheel back straight.

Yes, I have the same type of clanging issue. But I hope they are not THAT bad for my wheel to fall off.
Good luck with the LS460!

https://cimg4.ibsrv.net/gimg/www.clu...fc50f5e06d.jpg
I have always used my eyes and hands, look and see if the bushings look worn or disfigured... and take my hand on the ball joint and wiggle it around...