Successful AHC refresh - my experience and quick writeup

[ChaoticSquare]

the springs may be not be necessary. it can sustain for very long time.

I am overly preventive on maintenance. Get everything else done (minus the springs if that's your prerogative) and see what techstream shows. To me nothing is worse than one day realizing your car rides poorly. I’d rather do everything at once and then not worry for another 10-15 years aside from fluid flushes.

 

[IndroCruise]

I am overly preventive on maintenance. Get everything else done (minus the springs if that's your prerogative) and see what techstream shows. To me nothing is worse than one day realizing your car rides poorly. I’d rather do everything at once and then not worry for another 10-15 years aside from fluid flushes.

Applause!!

I replaced ‘globes’ at 183,231 kilometres (113,873 miles) after 13 years on the vehicle with the “HI/LO Test” registering 8 graduations at the AHC tank at correct AHC pressures. Rear spring replacements followed at 192,465 kilometres (119,592 miles) with King KTRS-79 -- plus airbags inside the springs which may have been overkill, very rarely used, but good for tongue weight if I get around to towing anything heavy.

This was a conservative approach and maybe these replacements could have been deferred.

The motivation at the time was that several very long cross-country trips were coming up on backroads and trails with the vehicle heavily loaded. So this was a “no regrets” thing – better peace of mind than risking failures in remote places while trying to extract the last few months of life out of components. Also much, much better than having to explain to Mrs IndroCruise why she had to help with preventable breakdown repairs or vehicle recovery from the middle of nowhere – which actually is my guiding principle on preventative maintenance!! So I have a few spares with a few kilometres (miles) on them sitting in the garage. I don’t carry them – generally I only carry spares for things that I think might physically break when unintentionally abused (along with plenty of fencing wire, cord, duct tape, recovery gear, and tools). I prefer early replacement of wear items including important major components like alternator, waterpump, hoses, starters, steering rack and pump, front and rear suspension mechanicals, etc, etc. New items already fitted seems like a better idea for reliability than a pile of new items sitting in the back of the truck as spares awaiting breakdown. ‘Globes’ in good condition are not going to fail suddenly any more than conventional shock absorbers might fail suddenly – and I don’t know anybody who carries a complete set of spare shock absorbers in their travelling spares.

Very leaky Front Shock Absorbers (and their bushes) had been replaced long ago -- at only 141,900 kilometres (88,172 miles). Should not have happened! Then I discovered IH8MUD, started learning about the AHC and TEMS systems, starting with the unadjusted effect of my very pretty but very weighty ARB Deluxe Bullbar on Front AHC pressures!!

Now I just need to find the courage to pull the Rear Shock Absorbers (no leaks, no rust) and replace those tired bushes ....

 

[scanderson76]

Kind of funny that we have the same idea! Glad I found this post. I wasn't thinking about those extra o-rings, I will have to grab those before I start this. Glad it worked out for you!

 

[LndXrsr]

Love your quick summary and thanks for the bushing part numbers. Just did this over the weekend. I would say I got moderate improvement, I think the most benefit out of the new bushings and cushions. My globes were original from 2000 with 210k+ miles on them, but still gave 10-12 gradations on the H to L test, so maybe that's why I didn't notice a night and day difference. Still, worth the time and

I left the o-ring and plastic ring in the AHC plumbing alone, FWIW. No leaks.

I was going to do the rear lower bushings +/- the cushions if I could get things off, but going back there made me realize what a pain it would be to remove and press in a bushing without removing the shock and how impossible getting the AHC plumbing and 22mm nut off the back would be. So the rear stayed as is.

 

[Bsherv87]

Just ordered all the parts to get this done. Was going to just to the globes, but this thread convinced me to go ahead and spend another $150 for the bushings, and get it all done together. Looking forward to an improved ride as mine is all original with 280k and 7 graduations on the test.

 

[suprarx7nut]

Awesome to see AHC refreshes on here gaining ever more momentum. It wasn't long ago all you could find were AHC conversion threads. I'm due for bushings on my 06 and expecting a significant improvement at 245k miles.

 

[Bsherv87]

Awesome to see AHC refreshes on here gaining ever more momentum. It wasn't long ago all you could find were AHC conversion threads. I'm due for bushings on my 06 and expecting a significant improvement at 245k miles.

I am new to the Land Cruiser world, and 4x4 world in general. I picked up a stock 2000 LX470 and got talked into taking it to GSMTR at Windrock OHV park in Tennessee.... I truly could not believe what this stock truck made it through. Stock AHC system with 280k and only 7 graduations took us on an 8 hour trek through some pretty rough stuff (for a rookie)... then on the trip back to Florida it rode like a dream.

I decided I like AHC quite a bit and for less than $1,000 I can refresh all globes, bushings, and fluid... no brainer.

 

[kookylukey]

Hey all, just got my 05 LX470 at 154k a month or so ago. Baselined the AHC fluid, corrected pressures (still ever so slightly on the high side) and got 8 graduations on the test. Anyone have any idea how much life the system still has? I just keep reading here that at 7 it's the end of the service life and don't want to go hard wheeling or anything too serious if it won't be able to handle it

 

[suprarx7nut]

I am new to the Land Cruiser world, and 4x4 world in general. I picked up a stock 2000 LX470 and got talked into taking it to GSMTR at Windrock OHV park in Tennessee.... I truly could not believe what this stock truck made it through. Stock AHC system with 280k and only 7 graduations took us on an 8 hour trek through some pretty rough stuff (for a rookie)... then on the trip back to Florida it rode like a dream.

I decided I like AHC quite a bit and for less than $1,000 I can refresh all globes, bushings, and fluid... no brainer.

The only other considerations would be rust and height sensors. Those height sensors are another wear item, but they last a very long time. Start a little piggybank for those so you're not caught unprepared if/when one finally starts to die on you.

Hey all, just got my 05 LX470 at 154k a month or so ago. Baselined the AHC fluid, corrected pressures (still ever so slightly on the high side) and got 8 graduations on the test. Anyone have any idea how much life the system still has? I just keep reading here that at 7 it's the end of the service life and don't want to go hard wheeling or anything too serious if it won't be able to handle it

How much life in the system?

1. Well, the globes are nearly expired at 8 gradations. That's essentially dead. Some rough back of the napkin math here: You get around 4 gradations just moving the car up and down with zero displacement of the globes. New globes return somewhere around 14 grads. That tells me you have essentially 10 grads (14-4) of globe displacement with new globes. If you get 8 grads, then really only 4 grads are moving the globe volumes. So you're at ~40% of the OEM design's shock absorbing ability. It's time to change the globes.

2. The system as a whole has a nearly indefinite life if you can avoid rusty hydraulic lines. All the wear items are relatively quick and easy to replace and the non-wear items are among the most reliable components on the vehicle. AHC gets a bad rap because so many owners completely neglect all wear items until failure and mechanics generally know nothing about the system so they struggle to efficiently identify and address the failure. If the car is not rusty and you want to keep AHC, you can keep it running well for decades.

 

[kookylukey]

The only other considerations would be rust and height sensors. Those height sensors are another wear item, but they last a very long time. Start a little piggybank for those so you're not caught unprepared if/when one finally starts to die on you.



How much life in the system?

1. Well, the globes are nearly expired at 8 gradations. That's essentially dead. Some rough back of the napkin math here: You get around 4 gradations just moving the car up and down with zero displacement of the globes. New globes return somewhere around 14 grads. That tells me you have essentially 10 grads (14-4) of globe displacement with new globes. If you get 8 grads, then really only 4 grads are moving the globe volumes. So you're at ~40% of the OEM design's shock absorbing ability. It's time to change the globes.

2. The system as a whole has a nearly indefinite life if you can avoid rusty hydraulic lines. All the wear items are relatively quick and easy to replace and the non-wear items are among the most reliable components on the vehicle. AHC gets a bad rap because so many owners completely neglect all wear items until failure and mechanics generally know nothing about the system so they struggle to efficiently identify and address the failure. If the car is not rusty and you want to keep AHC, you can keep it running well for decades.

Thanks, that was along the lines of what I was thinking. I don't think it rides rough or anything right now, so I'll probably keep a look out for some cheap globes, but good to know it's fine to drive on. Luckily truck doesn't have any rust so the lines should be more than fine.

 

[Coin]

Just an update. I replaced the front shock bushings on Saturday along with both upper ball joints (both were shot). Not a difficult task, but it took me all day. I'm slow. The ride is dramatically improved. How much is the bushings versus ball joints I can't say, but I'm glad I did it. I intended to do the rear shocks as well, but ran out of time.

I will say an offset 22mm box wrench is going to be your best friend on the top shock nuts.

Once I get the rear shocks done, the only bushings I'll have left to replace are the front control arms and body mounts. It's really starting to drive like a new car!

 

[Bsherv87]

Just finished doing all 4 globes, as well as all the bushings on the front rams. Ride is definitely improved, but haven't had enough seat time to really feel it. My graduations went from 7 to 14

Wasn't very tough at all... I followed the instructions posted in this thread... Globes came off on the first try.