Doing due diligence on this.

Observe the video for deflection & noise the thing makes:

My plan is to replace the following with OEM (I'm not re-bushing, I'll be putting in entirely new assemblies including an entire new rear knuckle):


48710-50050 Arm Assy, Rear Suspension, No.1 Rh
48720-50030 Arm Assy, Rear Suspension, No.1 Lh
48780-50021 Rod Assy, Strut, Rear x2
48730-50021 Arm Assy, Rear Suspension, No.2
42304-50080 Carrier Sub-Assy, Rear Axle, Rh
42305-50080 Carrier Sub-Assy, Rear Axle, Lh
90369-43005 Bearing x2

Are there any other while you're in there's I'm missing? The upper A-arms (48770, 48790) have already been replaced on both sides. The only thing that comes to mind are axle seals, but those don't really fail on this car & mine are bone dry. They seem to be lifetime parts & only fail due to neglect or mis-diagnosis for some other issue (leaking diff, slammed car, etc).

Also planning on ordering all new nuts\bolts\washers. It's like 17 cents, may as well.

 

I think rear knuckles are already discontinued. I searched Bell Lexus parts and they're not available.

 

Holy ****. 42304-50080 is discontinued on Amayama, but the other side is still available. You're right. It was in stock less than a few weeks ago when I was first scouting this build.

Lexuspartsnow has both of them... at double the price.

Ya gotta do this now. Parts are running out.

 

I have a 1999 LS400. Should I be doing the same thing?

 

Depends if it's worth it to you. It's not a cheap process by any means.

 

The sad fate of all the cars I have loved years beyond when they were released.

 

Just my opinion but I should be careful about counting on parts availability at LexusPartsNow. I ordered a pair of rear air struts and the under-engine cover which were not listed as unavailable and after almost having a heart attack from the cost of shipping ($360!) I received an email saying that one of the struts and the under-engine cover were unavailable. For the next several days I went back to the website and the parts were still listed, so I wouln't necessarily count on them being available at that source.

 

This has been my experience as well. LexusPartsNow is not a reliable indicator of what is in "stock"

Amayama is much more accurate in their parts availability. If they say it's discontinued, then it is. It is the harsh reality of our aging beasts that unfortunately do not share many parts with other Toyota platforms.

 

you could install those Febest bushings I posted in the other thread, my car is considerably more stable on the highway now and tracks straighter just by doing these. My Right side floating bushing was compromised and had some slop in it so i had to do it. I also bought all the bearings associated to do the rear knuckles, but its a ton of work to do all that even though I have a mechanic friend with all the press tools and lifts necessary.

This only took us about an hour to do total to press out/in both bushings once the car was lifted and arm removed.

 

Yeah I saw your other post. That's just one bush though, I'd like to do all 6. And my car needs all of them, especially the one in the video which had an incredible amount of movement. But maybe the others do too, I can't exactly laterally load the car on the lift. Fabest sells 5 out of the 6 so, it is a viable option.

I spoke with the shop who will do the work and they're unsure about how to quote the job, so I can't really make an accurate judgement on which route would be better to go down. I think they were under the assumption that you had to remove the knuckle to press out the bushes from it. I saw on another thread that this was not necessary, you can cut a hole in the dust cover and press out the bush without too much trouble.

I have an appointment with them in a week, since I didn't bother getting into the nuance on how was\wasn't possible over the phone with them. I'm contemplating using the Fabest bushings though, if it can be proven to be the more cost effective option. Especially if it means the knuckle doesn't need to be removed from the car, which, it shouldn't.

Since now, unknown to me, the knuckles are out of production... and maybe unavailable... A hybrid approach may make sense here. Fabest bushings on the knuckles, connected to 3 new OEM control rods with one remaining original bushing on the knuckle.

 

There should only be two bushings per knuckle so total of 4. The other hole is for a tierod end style balljoint that gets inserted into the knuckle and tightened down similar to a front upper control arm balljoint.

 

And see I learn something new every day. I've been neck deep in this for weeks and I had no idea.



So when you buy the OEM rod, that comes with a that new ball joint. Which just bolts to the empty hole in the knuckle, no bushing involved. And this is why Fabest doesn't have a bush replacement.

Got it. Thanks!

 

yes, there is a total of 6 arms and 4 bushings and that will completely solve the lower suspension in the rear, and then just have rear upper control arms which if you buy from Lexus, takes care of the bushings and the balljoint altogether. I did that back in May 2020 they ran me $177 a pop, had to ship out of Chicago to Ann Arbor, MI but they were available at the time.

My rear upper arms were VERY sloppy and contributed a lot to the wandering effect and loose rear end. Then when I did the rear knuckle bushing just a few weeks ago, it tightened up the car even more. So many little bushings to worry about in the rear end compared to the front.

 

Yup I did the upper A arm a few years ago as per your story. Drivers side had already been replaced before my ownership, I did the passenger side.

 

I've been here for 5 years and I didn't really realize until now just how Amayama really is wholesale price. It's incredible what you can get done. I think I've fallen victim to mission creep lol. But I'm committed to doing this at this point - and I'm excited to see the difference in how the rear end feels after freshening everything up. The amount of slop, uneven landing and 2ndary vibrations back there is really unpleasant.



$750 shipped to replace every bush in the rear end, steering rack bushings (six bucks each!!!!), throttle cable bushing, sway bar links, 8 or 9 different vacuum line and vent hoses, spark tube seals\valve cover gasket...

Will be pulling the trigger and ordering these parts most likely next week. Will be doing the hybrid approach mentioned earlier. Press out bushes on the knuckle, replace with fabest. This requires punching a hole in the dust shield of the brake rotor so that you don't need to remove the entire damn knuckle to press out the bush which is parallel to the axle line. Everything else is full OEM since the parts are available and super cheap (like $60\ea).

Will be using my local trusty mechanic for the rear axle stuff + alignment since that is pretty far out of my paygrade. Will probably do the steering rack bushes myself, along with all the vacuum hoses. I'm on the fence about doing the spark tube seals myself. The Car Care Nut did this job on his LS430, which is 98% the same process as my engine (I'm guessing) and it seems daunting taking the valve covers off. But it's doable especially since he documented it well. I just worry about running into an issue where I don't have the correct tool\extension and being stuck.