You're more than welcome for the suggestion.

Old fluid may have partially lost it's ability to lubricate...same as engine oil, brake fluid, transmission fluid, etc. Off topic, I also don't accept Toyota's claim of "lifetime" transmission fluid.

My first step would be to ask dealer to check AHC pressure on all 4 wheels, and request a printout of the results.

 

Makes sense on the fluid losing some lubrication ability.

On AHC pressure on all 4 wheels- how do I know what's an acceptable range? I googled and read a few of the top threads that popped up on the IH8 forum but didn't look like anyone had the information (though many were requesting it). Thank you again.

 

TIS aka Toyota Information System will show pressure. A functional check without TIS shows up here http://workshop-manuals.com/lexus/lx...ard/page_6432/ with specifications on the next page following the link. You can diy it and all you need is a tape measure.

hth

Steve

 

Picking the truck up today- they didn't find anything wrong with the AHC. The technician drove it a few times to get it up to speed where the height changes, then took it back and performed multiple diagnostic tests. Said everything is within specifications. On another note, they did replace my rear tailgate motor and assembly because our push button operation of that wasn't working. Not sure of the cost of that since I'm under CPO, but it's another reason I'm glad I bought CPO on this vehicle (replaced the suspension system just over a year ago under CPO which would have run me about $2k).