This forum has been a wealth of knowledge so far. I have gone from being clueless about cars in general to being gradually more informed about parts and general maintenance. I am trying to purchase the correct parts for rear struts (to be installed by someone else) for a 2009 RX350 and have become confused about the following: the strut mount comes with a bellows attached to it (like in the picture below). However, there is another part, 4892448020 (link), that also looks like a bellows of some kind that is secured using two metal clamps. This this 4892448020 an additional part from what is already attached to the strut mount?

 

The rear mount comes with the bellows built in, those other bellows are for cars with air suspension and won't fit

Some more info here:
https://www.toyotanation.com/threads...01-07.1719224/

 

Wow, the legendary MattRX! I've learned so much from reading your posts. A lot of it is still beyond me, but I hope to get there one day!

Thanks for the clarification about the other bellows. Does this mean that the metal clamps (48956 and 48956A in the picture below) go on the bellows attached to the strut mount?

Also, reading your strut guide, it seems like some of the nuts and bolts are not reusable. The only thing I know is that the lock nut top on the strut mount that secures the strut to the mount (48750J in the picture below) cannot be reused and a new one is supplied when a new strut is purchased. But there are quite a number of other nuts and bolts. Are they all reusable?

Sorry for these very elementary questions. Clearly I have a much to learn...

 

Welcome to Club Lexus and your 1st post and thread!

 

No problem! I was there too back then, lots of trial and error. Those clamps are also absent from our cars and are only for air suspension, the rubber boot is molded to the top of the strut mount itself. On the front, it's a separate assembly. The aftermarket rear strut mounts from Mevotech / Monroe and KYB are okay, but the front aftermarket ones do not hold up very well. The only non-reusable fastener is the one on top of the strut mount for the front strut as it is a nyloc and while it could be reused, it would be better to replace it. The rear strut mount nuts use an oval lock nut and could be reused. New struts I have ordered in the past have always come with a new lock nut.



Coil spring diagram for rear suspension (The top nut is marked as non-reusable, but this nut can likely be reused many times without fail unlike the nyloc front strut mount nuts)

 

Thanks so much for the confirmation that the metal clamps are not part of the strut assembly. Prior to making this post, I looked at the old struts and there are no metal clamps on there, but I couldn't figure out at the time whether the clamps fell off or were never there to begin with, as the bellows are very torn up by now.

I picked up the order of the rear struts earlier and there is indeed a new lock nut in the box!

Regarding the rear strut mounts, I did order some, as someone else will be doing the replacement and I don't want them to disassemble everything, only to find out the mount is not in good enough condition to be reused (even though the likelihood of being able to reuse is high). However, for future reference, how do people typically determine whether the strut mount needs to be replaced? It seems a spring compressor needs to be used(?) to take off the strut mount to look at it, which sounds challenging.

 

The rear strut mounts are just a rubber puck, the front ones on the other hand are a lot more complex because they have to steer and use a bearing and more hardware between the insulator and bearing. For the rear, you just replace them if they're ripped, for the front, I've seen the bearings fail in the mount and the result is a very crunchy feel in the steering, pops & clunks up front near the top of the strut towers, or binding. Some care has to be used with the spring compressors as that spring is under a lot of tension and could injure you. The best spring compressors are ones we had at the shop that are mounted to the wall.

 

Thank you again MattRX! I'll have to read through your posts on Toyota Nation too. I'll keep the info about the strut mounts and bearings in mind for the future. Hopefully the front struts will not need replacement for a while. The parts seem much more complicated.

 

They're a little harder to put together as the bearing needs to be placed the right way and the mount needs clear in its range of motion, but it's still actually pretty simple.

 

I hope to one day be able to replace at least the rear struts myself. Simpler repairs like brake pads would be my next step, as I have essentially no experience with car repair. There is a lot of learning to do!

Also, I'm posting this here, in the unlikely event that someone else gets confused like I did and finds this thread. On the Lexus and Toyota parts website, there are very useful pictures of the different parts for every car model/year they have. They have 2 different diagrams for the rear suspension for the 09 RX350, which I've posted below. One is for the normal struts (48530, 48540), which have springs. One is for the sport struts (48080, 48090), which do not have springs. (Another thing I didn't know about: there exist struts that don't have springs.) The two pictures below clearly have the struts labeled with different numbers, but I didn't notice the first time around that the struts had different numbers and got confused. The bellows and bellows clamps I was confused about are only on the diagram for the sport struts, just like MattRX said. Thanks MattRX!

 

Best to pass on the quick struts, Get a pair of KYB struts & use your oem springs