https://www.drive2.ru/l/584545737254125778/

RAHC adjustments

 

Well, I got it thawed out, and it works again! So I guess I got something packed too full of snow, or I was working the system too hard and it shut down, hard to say exactly what happened. Thanks for the suggestions!

 

Hi I just put on new tires and now my rear suspension bottoms out. I had this happen a few years ago when I got new tires then too. All of a sudden the rear suspension would bottom out way too easily. I replaced the avs shocks last time and it helped a little until I just recently put tires on and it got worse again. I finally made the connection that they did not turn off the Rear air suspension before putting it on the lift. The Lexus service guy I use said if they don’t turn it off it can cause the bags to disconnect or stretch out. This is now making more sense. Any comments or help would be awesome. Thank you.

 

The GX is an offroad vehicle capable of full suspension (rear axle) articulation ... so lifting at the tire shop will not cause any issues with the airbags or airbag system. Since your service advisor is a moron, ask them if lifting also damages the muffler bearings.

 

There is an off button for the rear air suspension. The manual and Lexus state the the suspension must be turned off prior to placing car on a lift or towing. But thanks for responding, I completely disagree with you. Calling someone a moron is not respectful either.

 

I would hope the shock would "bottom out" before the airbags stretch to the point where they fail.

What happens if you go off-road and over articulate?

 

This is a safety issue for the operator, it won't damage the suspension
The manual actually states:

WARNING
■ The rear height control air suspension must be turned off Be sure to observe the following precautions. Otherwise, the automatic leveling function may cause vehicle height to change, and you may catch part of your body in the vehicle, resulting in an accident: ■ Selecting the correct height mode

 

My original point exactly ! Yes, the shocks would limit the maximum extension ... no different than when extreme off-roading ... no different than being on a lift at the tire shop. IanG has this right ... not an issue for the Lexus GX ... but maybe an issue for the Lexus IS suspension ?

Sorry nhagon for being blunt ... but one would expect and should demand that a Lexus Service Advisor understand their products, and not send a customer off on an unnecessary tangent.

 

Research past posts on Timbren Bump Stops ... excellent upgrade as a replacement for the harsh stock bump stops that allow a significant amount of force to translate into the frame ... even when going over speed bumps. The Timbren Bump Stops provide more cushion and are well worth the cost of upgrade. If your air bags were to fail, these are robust enough to prevent damage, unlike the stock bump stops.

 

Still not seeing a reason why the OP has experienced this twice with a lift used for new tires.

 

Coincidence ? ... "bottoming out" is the only symptom described ... nothing said about the associated (rear) ride height. If the air bag(s) or the air bag system has/had issues, the ride height would have been mentioned as well ... unless the air pump was working overtime to compensate for a (slow) leak. Assuming this is not the case ... the OP may want to check the rear height sensor ... specifically that the "neutral" sensor position is where it should be in terms of "neutral" measured ride height.

So question to the OP ... when this happens ... what is the vertical height measurement from the ground to the edge of the rear fender opening, centered on the rear axle ? I assume you are running the stock 265/65-18 tires.

 

Hi all,

I recently purchased a 2010 Lexus GX460 premium with 180k miles. I have noticed that the rear will sag when its been sitting. I will start it up and hear the air compressor kick in to raise it back up. (I was preparing to have this checked out and possibly replace the air bags. Though I just had the all wheel bearings replaced and wanted to recoup after that bill.)

Anyways, a couple of days after picking it up from the shop (wheel bearings), the rear is sagging and the air compressor is not kicking on. I go to adjust the height...NOTHING. It does not switch out of 'N' on the display. Though no warning lights on the dash.

Any details? Will this turn into a compressor AND airbag replacement?

Thanks for the help/advice!

 

Possibly.. probably want to pull codes

https://www.clublexus.com/forums/gx-...and-gx460.html

https://www.clublexus.com/forums/gx-...-and-rahc.html

https://www.clublexus.com/forums/gx-...-problems.html

 

I, and I bet many members on this site, have never turned off the air suspension before lifting the GX and never had this issue.
Like mentioned in previous posts, I think it’s for safety because otherwise the vehicle height can unexpectedly change on you while lifting or lowering and crunch something.

Seeing that you had this problem twice, either there was already a component failure, which has not been fixed yet or the place you have the tires changed does something they're not supposed to.
Has it been the same place both times?

 

The "Key Off" lowering would be deactivated as well with the use of the ON/Off switch.