So, my 2007 IS250 MT has developed a knocking sound in the back. It mostly occurs when moving from and stopping to a standstill. Took it to a mechanic, he thinks it's driver's side rear knuckle bushings. They are part of a "CARRIER SUB-ASSY, REAR AXLE, LH" PN 42305-30090, however the bushings don't have a PNs of their own and are not sold as OEM parts separately, as we could tell. However, just googling that PN yields few results on Amazon and Ebay, which sell the aftermarket bushings alone. Probably made in China... Like this Amazon set:

What do you think? Should I order them? Might as well give it a shot, cause I'll be paying cca 400 USD and waiting over a month for the whole assy to arrive from Japan (local Lexus dealer would probably charge me 3x that, and they probably don't have it in stock either)

 

Mine is doing something similar. Mine is a 2011 250 with a manual transmission. The knuckle can only, as far as I can tell, be ordered from Lexus, and that's the only way to get the OE bushings from anywhere. It would probably be possible to source them from the bushing OEM, but I couldn't find that information. The knuckles are $1052 each (Canadian) where I live, so I opted to service the knuckles I have.

Anyway, I found a kit on eBay that includes all 3 bushings for a knuckle in one kit. This is the one I got; I had to order 2 kits, obviously. I am going to be doing both sides.

I am still trying to figure out what the best solution is for me: do I bring both knuckles and the bushings I bought to the shop up the road to see if they can fit them, or do I try ******* around with a c-clamp press kit to get them out myself? I prefer to do my own work because I will always go the extra mile to do things like properly clean out the bores where the bushings will go, put a bit of lube in there, clean things up, etc... whereas a shop will not.

I deduced that it must be a worn bushing that I'm hearing because neither anti-roll bar drop link is making noise, nor are the ball joints. If I rock the car up and down at the rear, I can hear the sound. It really only happens over the lumpy gravel on my road, or pretty bad cracks in the pavement.

Have you decided what you will do?

 

Hello Jeeves, thanks for replying. Nope, not yet. Got a phone number of a guy who works at Toyota dealer warehouse, I'll try checking with him first. I'll would bet these are probably just generic Toyota bushings that you can find on dozen other models, but for some reason they are not specified as separate parts on Lexus schemas... If they are not available, I'll try the ones from your link. Please let me know your impression of them, after the install.

 

I will. Hopefully they are the correct size. I’m just trusting some rando on the other side of eBay at this point. I wasn’t even able to find bushing dimensions when I was Googling around before I ordered.

Let us know if your warehouse guy finds part numbers!

 

Hey, sorry for the late reply. Unfortunately, my contact was of no use. Tried also contacting some other ppl who work for Toyota, unfortunately they were of not much help either. Basically, here were i live, these are somewhat exotic cars, so even Toyota mechanics are not that familiar with doing things that go outside "standard procedure". And the standard procedure is to basically swap the whole assembly. Apparently it's a deliberate policy by Toyota, because they don't trust their dealers to press in bushings properly, so they are not offering them as individual parts in their catalogues...

Have you done eBay ones? If so, how did it turn out?

 

Hey! Not yet; I did order the bushings, but I am waiting for the weather to warm up and for a few days in a row where I don't have stuff to do AND I don't have to drive to the office so I can do it the way I would like to.

The plan is:

1) Get the car outside, take the rear wheels off and blast the **** out of the undercarriage to clean as much winter filth out of there as possible with the hose and power washer. I live in Ontario and my house is on a gravel road, so the bottom of my car gets all crusty every winter. Looks like concrete. I wash it off at the self-serve carwash in town whenever I can, but that's 30 minutes away from my house. Even then, with the wheels on, it's hard to get at all of the nooks and crannies.
2) Take the car back into the garage, and do one side at a time so I have one to refer to in case I lose my place or get confused.
2A) Once I have the suspension apart, I will be closely inspecting the mounting points for corrosion and treating them with phosphoric acid and some heavy duty black paint. This will add like a day or so to each side, just waiting for chemicals to work or cure.
2B) I have bought and set up a hydraulic press; I will use that to push the old bushings out, and the new ones in. While I have the knuckles off the car, I am also going to take the time to press the old wheel bearings out so I can fit the new brake backing plates I bought; the old backing plates are badly corroded. I have new Timken bearings to press in afterward if the old ones seem perished.
2C) I will also be greasing my handbrake cables to make sure they're nice and slidey.
3) Do the second side.
4) Success?

I should probably document it and write it up while I'm doing it. These cars are getting old enough where I'm sure I'm not the only one with mystery noises from crapped-out old rubber these days.