AHC History - Heavy vs Light

[BookerNoe]

Guys - I am looking at several LCs and LX470s before I pull the trigger and I see some that have addressed different components in the system 4x, and then others on the Lexus portal that have 0-1. Am I to assume that if you have several issues with the AHC its more of a systemic issue?

From what I have learned of that system, its more of just maintaining the Nitrogen Globes religiously and not having some JA put something like Brake Fluid in there.

 

[TXLX100]

Basically that's all there is to it. Keep fluid changed out regularly and keep the pressures within spec and the system will have optimal longevity. Globes and rear springs will eventually wear out and rare height sensors failures. Very similar to the rate of failure and maintenace in any other hydraulic system.

 

[Moo87]

Hello, I'm new here but not new to the 100. I've been really looking into these AHC systems, and I'd like to add a few things that I've noticed talking to the dealers and lookings at service records. The AHC fluid are rarely serviced at their proper intervals, let alone early as good preventive maintanence and that's the same neglect I see for front and rear differantials and transfer case fluid. IMO these are really important service for full time 4WD vehicle if you want those expensive components to last as they age. So if I was in the market, and don't see differentials and transfer case fluid change around every 30K or earlier, and AHC fluid change around 60K or earlier, I 'd wonder what else did the owner/owners and the dealer cheap out on? Hope I'm not stepping on anyones toe.

 

[jLB]

Hello, I'm new here but not new to the 100. I've been really looking into these AHC systems, and I'd like to add a few things that I've noticed talking to the dealers and lookings at service records. The AHC fluid are rarely serviced at their proper intervals, let alone early as good preventive maintanence and that's the same neglect I see for front and rear differantials and transfer case fluid. IMO these are really important service for full time 4WD vehicle if you want those expensive components to last as they age. So if I was in the market, and don't see differentials and transfer case fluid change around every 30K or earlier, and AHC fluid change around 60K or earlier, I 'd wonder what else did the owner/owners and the dealer cheap out on? Hope I'm not stepping on anyones toe.

I believe I remember that the Lexus service interval for AHC fluid is 60,000 miles.

I don't recall a direct recommendation for fluid replacement for the diffs nor transfer case from Lexus/Toyota. There is an "inspection" for these fluids every 30,000 miles, and you'd expect that they would get replaced a some of these inspection intervals. I'd be more concerned by a vehicle that had them changed at every 30,000 miles. I'd be wondering how/why the vehicle was abused in such a fashion that these fluids were failing/contaminated at this frequency...

 

[RKRUGER]

I agree... but in my experience, the AHC fluid was rarely done because they never used the button.

I am guessing we are all the 1%ers... we use all the buttons; POWER, Height, Ride setting... How many soccer moms ever raised their vehicle into high setting? Probably none.

When I bought my '06 LC on the internet, I had the gal hold a tape next to the front wheel arch and the rear wheel arch and take pics in L, N, and H. I could see that it worked. It wasn't until I registered the truck on Toyota Owner that I got service level detail and that detail showed part numbers for the AHC oil. I still bled a can off when I got the truck here. Didn't completely beleive the stealership in DC actually did the work, but the oil was a clean as could be.

Service records for my truck at the 90K service showed $2800 in parts and service. All drive line and AHS fluids at the same time as TB/WP service. Guy didn't skimp.

 

[TXLX100]

I think the service interval is actually 30k miles on the AHC, or at least that's what I have always done. I'd say it's MORE important to changed the AHC fluid than the drivetrain gear fluids. The components in the AHC system are very sensitive, especially if water enters the system (very old fluid). A well maintained AHC system can last a very long time, or be like mine when I bought it and is riding stiff since 110k miles.

 

[jLB]

I think the service interval is actually 30k miles on the AHC, or at least that's what I have always done. I'd say it's MORE important to changed the AHC fluid than the drivetrain gear fluids. The components in the AHC system are very sensitive, especially if water enters the system (very old fluid). A well maintained AHC system can last a very long time, or be like mine when I bought it and is riding stiff since 110k miles.

Not that 30k is a bad idea, especially as these systems get older, but at least on the 06 LX the factory recommendation appears to be 60k or 72mo intervals:

http://drivers.lexus.com/t3Portal/document/omms/06LexSCHU_MS0011/pdf/06LexSCHU_MS0011f.pdf

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