Took my month old '08 RX 350 to the dealer for an oil change to synthetic. Had them do the once over and check everything. I was getting a thunking noise in the right rear while going slow over bumps, potholes etc. Dealer said both rear struts are leaking, the right one was pretty bad. Okay that explains the noise, dealer quote $1355.50 to replace both rear struts and mounts. Found the OE KYB struts on Rockauto for $67.99 each and the mounts $42.49 each. I'll be visiting my favorite mechanic for the install. My question is, should I replace all 4 struts as long as I'm changing the rears ?

Dealer also said my steering rack is leaking, replacement is $1627.00. I haven't noticed the PS fluid low but I'll keep watching it.

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2008 RX 350 Flint Mica/blk 81,000 miles
1998 SC 300 DWP/beige 144,000 miles

 

power steering rack leak is common. usually the leak is so slow that you can monitor it until it gets to the point it actually needs.

as for the struts, i would save some cash and just do the rears.

do a search, there was a guy on here that swapped out struts too and he complained severely about a harsh ride. keep that in mind.

 

If you're satisfied with how the front suspension performs, then I'd say save your money. I'd evaluate according to braking and body roll, since both of those involve shifting weight to one or both front struts. Correct me if there's a better way, since I'm not a mechanic.

 

You may want to consider monroe struts and just do the rear. I think they will be closer to oem

 

Stick with OEM strut mounts. Although it's a bit premature to replace them this early.

 

Maybe I'll go with the Monroe Sensatrac's or the other Monroe strut I just read about but can't remember right now, for the rear, I heard they were pretty good as being closer to original ride, and then just keep the stock mounts for now. Hopefully it's not the mounts making noise.

 

I would get a second opinion on the struts, you rarely see them go before 120k or so. If you do end up replacing them seriously consider using OEM, some of the aftermarket can change the ride characteristics.

You should also eliminate the world famous undercladding noise as a possibility. There is s large piece of plastic under there and the leading edge (on the drivers side) comes loose and makes a noise that can seem to come from all over the car. A little 3M double sided tape can fix that.

The steering rack can usually be done for 700-1000 at an independent.

 

Thanks Carver, I'll check the undercladding. It happens when I'm going about 15-25 mph and run over a manhole cover, it is definite thunk, clunk, that's not a normal suspension noise. I can see it better on the lift at the shop. If I need struts NAPA has OEM replacements. Do we get a discount at Sewell Lexus or something ?

 

My 04 Rx had all 4 replaced (under Lexus warranty) at 70k when I bought my RX I bought the Lexus warranty, and they covered everything.

Honestly time frames on struts are really hard to judge, driving conditions, weather, tire wear have an effect on the life span.

 

My front struts were both leaking on my 2007 RX350 w/ 68k miles (including the rack and pinion). I ended up replacing all (4) with the Monroe OESpectrum http://www.monroe.com/en-US/products/OESpectrum/

Very satisfied.