Over the last few months, I've started to notice an intermittent problem that seems to be in the rear suspension. At times, the ride of the truck is terrible and I can practically feel the painted lines in the road. Other times it seems totally normal.
I've also noticed that sometimes when starting out from a stop with the wheels turned (going forward or in reverse), I feel a binding in the driveline. It feels just like a part-time 4wd truck does if you have it in 4wd on dry pavement. Again, this also comes and goes.
I dropped it off at the dealer to have these checked out, as well as the infamous "clunk." They just called and told me that the diagnosis is the driveshast and control arms, and that could cause all 3 issues I described. I don't buy that at all.
I know this is the fix for the clunk, and that's great, although the parts are still on backorder. The problem I have is that the clunk is always there, while the other two problems are intermittent. I can't see how the driveshaft / control arms are going to fix the other two issues.
Those other two problems to me sound like a U-joint going bad for one, and for the other, a sensor failing in the rear suspension (ride height sensor maybe?)
Anyone ever have either of these two problems? If so, what was the fix?
Thanks in advance.

 

I would wait and see how the truck handles after you have the clunk fix done

I had all the same issues you had. The clunk fix resolved all of them for me.

 

That is really good to hear, considering my nearest dealer is about a 45 minute drive, one way. I was prepared to leave the truck there until the parts came in, but at this point they have no clue when that might be.

 

Ya, the time for the parts very, if you check the clunk thread.
Took my dealer about a month, then some have been waiting a couple of months now, some took weeks.

 

I have had the clunk fixed (took care of the clunk, BTW ) but I have noticed that my GX seems to "bottom out" when I drive slowly over speed bumps... The rear end hit with a force that reminds me of a vehicle with bad shocks hitting the snubbers... Anyone else experience this on speed bumps specifically? (Your mention of a bad rear sensor reminded me... )

 

Spoke with the technician this afternoon. Seems that when I described the three problems to the service person over the phone, the clunk was the only one they actually got right on the work order....imagine that. Once I was able to explain the issues to him correctly, he decided that the clunk fix might not be related to all three. They will be checking the truck out again tomorrow.

 

I have same problem. I have an CPO 03GX with 62K Miles on it and it does the same thing like it is stuck on first gear and engine sounds heavy, takes a little while to kick in to 2nd gear...and into 3rd. It is intermitent. I also notice it does it more often when A/C is on. I will be up for service next month. I will ask for them to inspect. Please give us update on your repair progress as I will too with mine.

 

Either my explanation of my truck's issues was bad, or I am not understanding yours, because they don't sound similar at all. I have no issues with shifting....did you just mean similar as in we both have an intermittent problem?

As an update, they basically did nothing to the truck today. Good thing I didn't need it, since they didn't even call to ask if they could have it for another day....I called them at about 5 minutes before closing for service.

 

sorry, i misunderstood. mine might have a different symptom as yours. you mentioned "binding in driveline" and i thought about it in different way. sorry. goodluck on your repairs.

 

Interesting - I have had a similar problem after the clunk fix. The truck used to ride smoothly over our lousy rodes, and I could pretty much ignore speed bumps if I wanted. Now I don't actually hit, but the truck really goes up and down.

I took it to the dealer several times - even took a test drive with the tech and went over speed bumps. Their response is that the roads are no good and I'm supposed to go over speed bumps really slowly.

There is no explanation as to why the ride has changed so much for the worst, or even agreement that there is a problem - they just say it is "normal".

I'm not really happy over this, as I used to love the ride in all conditions - it was one of the nicest things about the GX and is what sold me on the lexus SUV. I wish there was some scientific way to prove the ride has changed - say some specs and equipment to measure the movement over set road conditions.

 

Even when my GX was brand new, I dont think I can ignore speed bumps and dont feel it. The ride is stiffer after the TSB but it also made the GX handles a little better. Its all a trade off I guess. Even with the TSB, the GX is still pretty smooth considering its a big truck.

 

Interesting... I will need to bring it up next time I am in for service... We were driving home the other night through a construction zone; joint between the old road and new pavement... the impact was so hard my 7 year old daughter in the back yelled... Felt like there was no shocks at all... I was tempted to drive over the section of road at the same speed with different shock settings to see if that had something to do with it, but I doubt my wife or children would have appreciated being part of my test scenario...

Truth be told, I'd rather it bounce excessively than hit hard like that...

 

I have the same issue - since the TSB clunk fix the truck rides rough, much more than before the fix. I even had an issue one day I came to a light and when I took off, it was like the shocks had fallen off - no damping at all, it was like a pogo stick. I was getting ready to pull over and switch the damping switch from the normal position to one of the other positions and it suddenly was fine, switched it back and all was good (this was about 2 weeks after the clunk fix and a week after they had to replace both rear shocks as they somehow destroyed them doing the clunk fix and both where leaking badly a few days later)

It's scary that my BMW is the reliable car in the family - the Lexus is the POS that is always in the shop - hope they get the 09 right!

 

You are right. I hope everybody reads this who is experiencing a rough ride after the clunk fix or any adjustment service after which the ride sucks. I can't explain why this works but if you will cycle the vehicle while running through L (low) N (normal) and H (high) and then back to the normal riding height again, N (normal). Do this slowly each time until the light stops blinking each time and magically the ride goes back to being smooth again. I suffered through several months of terrible driving until I figured this out accidently.

 

Sounds like you have a problem with the rear height sensor.