BayAreaLex

+1, thank you for pointing that out. And were both of your bushings shot or just one? And lastly, did you buy the bushings from Ireland (ebay), NZ, or FIGS?

repugnante

The driver side one was so bad, I was taken back on how the thing was still held into place. The passenger side was "decent" however if I had only replaced the driver side, I'm certain the passenger side would've been more exposed to sound and more evident. The inner sleeve starts touching the outer sleeve of the bushing and that's where the metal clanking sound starts to become noticeable. I'm not sure that's whats causing the initial sound, but from my observation and getting an idea of the role of this bushing, I believe that is how that "popcorn popping" sound gets heard.

BTW, I was having the exact same issue as you. Popcorn popping sound in the rear. Clearly heard at low speeds. Unnoticeable at high speeds. However at high speeds, the rear wandered a bit. The average Joe probably wouldn't have noticed the wandering but my **** self certainly noticed it. That made me confirm that that knuckle bushing is way more important than I had thought. After replacing all of the suspension pieces on my car, that bushing fully exposed itself. The noise got so irritating, that when driving down the street, folks can hear it and turn their heads. Very embarrassing.

BayAreaLex

100% spot on.

I wonder what the typical life of these spherical bushings is. On my car after 95K miles both sides are toast. Which bushings (and from where) did you use for replacement?

repugnante

I'm clueless on the lifespan. But I can tell you that when I first purchased the car (about 80k) I could've sworn I heard that clanking sound back there. But the entire suspension was so worn out, I just figured it was one of the obvious parts that wear out overtime. It was faint back then, got progressively louder up until this morning when I replaced them. Now that I think of it, I probably should've gone with Figs because this bushing looks like it is more than just wear item.

There is a shop not far from me that specializes in Toyota/Lexus vehicles. I see them quite frequently and are like my personal guru's for Lexus advice. Last week I explained the problem to the mechanic and after a few words he immediately knew what I was referring too. This is a very common part that goes bad on the IS's as he's replaced these before many times but never on a GS. He agreed along with most of us here that we share the same knuckle as the IS. Fortunately, he had a set of these bushings brand new for an IS that a guy never came back for and sold them to me for $40. I don't know what brand they are, but they are virtually identical to what came off of the car.

repugnante

Oh and many, many thanks to Leon (OP) for providing the "light bulb" to this problem. Please sticky this thread. Many others are going to chime in with this exact same problem. Fortunately, the car doesn't collapse when these fail but in my opinion the knuckle bushing is equally as important.....

repugnante

Found these for the IS:

http://www.motorklasse.com/rear-knuckle-bushing-for-is300/

lyonkster

You're very welcome .

BayAreaLex

Here is a question for the suspension gurus.

If the carrier/knuckle bushing is shot, will that wheel tend to camber positive or negative?

The reason I ask is because my passenger side tire rubs on the outer fender on large dips (the side with the shot carrier/knuckle bushing) while the other side doesn't, which suggests that it would camber positive? Wonder if the rubbing is related to the bad bushing.

BayAreaLex

Another source... In South Korea, lol.

Gold star if someone can identify a vendor who has these in stock in the USA.

I just ordered mine from Ireland (eBay).

repugnante

Lol, yea these bad boys only seem to be foreign. I'm guessing the targets were the 01-05 Altezza's

BayAreaLex

Ya, seems off the wall that some vendor hasn't tapped that revenue opportunity here.

I'm going to get my hands on the autozone ball-joint press: #27023 Hopefully this tool will work like a charm and is appropriately sized.

DriftChris

I used that ball joint press kit on one side... I dont recommend it. Its really hard to do correctly because the cups dont sit flush against the knuckle and it was really hard to do without removing the entire knuckle. If you want the easiest way to do it. (Definately more time consuming but worth it.) Remove the whole carrier assembly and take it to a machine shop to have them pressed in. Or get that expensive Balljoint press kit.

I did the passengers side with the kit from autozone it was a nightmare and I had to remove the other side to do a wheel bearing anyway. Took the drivers side to a machine shop to press in the wheel bearing and the bushing 65$ and painless and it was done correctly within a day.

Also I am vouching for the Figs Sphericals being the best solution instead of getting OEM or OEM comparable. Day and night difference from New to old to FIGS replacement. Also thanks for the great customer service Mike.

FIGS

iTrader: (11)

Thanks, we worked through the tolerance issues and are working on getting more bearings in stock as Aurora is backordered for 6 weeks. We are going to qualify bearings from FK this coming week and keep a tighter eye on inner fit tolerance as well as delivered tolerance from our bearing suppliers.

repugnante

Figs, though I went with the OEM type bushing, I'm still considering yours since these tend to have a habit of wearing out early and yours appears to be rock solid enough to last for years and years. I noticed that I couldn't press the OEM ones in by the inner sleeve. Would that be the case with yours as well?

FIGS

iTrader: (11)

Ours are more serviceable for sure. You need to press on the outer cup which is not difficult to do with a 34mm socket. once installed if you need to replace just the bearing, you can remove the 2 snap rings and press on the outer ring of the bearing itself. Never press on the inner ball area as this will relax the bearing race fitment. The bearing cost will be much lower than the full assembly in the even it does need replacing. We have seen around 80k miles of service on these bearings in open element use.