Definitive list of AHC maintenance items (4 Viewers)

[Jaybob]

Use only:
GENUINE TOYOTA 08886-01805 SUSPENSION FLUID

Yes - I was asking because the Toyota parts guy said that it was discontinued. I bought their last can, then purchased one online. Looks like it's been replace with the 1L bottles then, huh?

 

[DirtDawg]

Yes - I was asking because the Toyota parts guy said that it was discontinued. I bought their last can, then purchased one online. Looks like it's been replace with the 1L bottles then, huh?

I would take the parts guy's word with a grain of salt. They have been known to be incredibly wrong in the past.

 

[flintknapper]

Never saw the plastic bottle version, but after a beer or three, I would use that stuff as an ATF, according to the picture. Bad t0yota.

Yeah, why would they put a big honking transmission shifter on the front of the container? Hope they didn't change the color from pink to red!

 

[JTinAZ]

What was the 1L price?

$15 retail

 

[DJCloz]

I read through a lot of that and didn't find my answer. My 99 LC is non-AHC, but I just convinced my cousin to buy a 01 LX. AHC works great. Question is, do AHC trucks also have torsion bar adjustments to bring up the front end? or "level" it?

 

[PabloCruise]

I read through a lot of that and didn't find my answer. My 99 LC is non-AHC, but I just convinced my cousin to buy a 01 LX. AHC works great. Question is, do AHC trucks also have torsion bar adjustments to bring up the front end? or "level" it?

Yes they do.

 

[PabloCruise]

Now that the trip is over, and I have some time to play with this more, I will unpack everything and take a look at the truck...

Do I still have cross-level?
How are heights front and rear?
Now that I have seen the FSM height sensor adjustment, I can adjust those.
Then adjust torsion bars for 6.9 Mpa up front and see what the rear pressures are. Maybe play with rear height sensor a little if it will help rear pressures. Rear sensor is pretty darn close to 0 as is.

I may start with air bags in the rear, just because I need one more thing that is adjustable to fuss over in my life...

So the steps in order are
Cross level
Adjust height sensors to get the correct height
Adjust TB to neutral pressure

Is that correct?

From what I have read in here, I believe that to be correct.

 

[PADDO]

I read through a lot of that and didn't find my answer. My 99 LC is non-AHC, but I just convinced my cousin to buy a 01 LX. AHC works great. Question is, do AHC trucks also have torsion bar adjustments to bring up the front end? or "level" it?

The torsion bars in AHC vehicles essentially do two things: 1) lower or increase front neutral pressure depending on how much they are tightened or loosened and 2) adjust the side to side cross level, just like in non AHC applications. If you want to "bring up the front" you adjust the height sensors which changes the set point feedback signal to the ecu and that causes the front shock actuators to be driven up a little more, or down a little more, depending on where you set the sensors. And if you raise the front height a bit you then should also adjust your TBs a bit to correct the increase in pressure associated with the increase in height. Search terms like "AHC sensor lift" or "neutral pressure" or "height sensor" for hours of fun reading

 

[bouncylexus]

Don't worry about the height accumulator pressure, there is nothing you can do to adjust it and I've seen 9.8 to 10.7 MPa before. There is no adjustment for your coils like there is for the TBs, it's repair by coil replacement or augment with spacers (30mm to be effective) and/or install airbags for temporary help and extra load support. The proper solution is to replace your coils with new and there is lots to be gained by installing spacers at the same time. It's not urgent you do this but prolonged high pressures can't be good for the system (think weeping shocks) and the ride is so so much better when the pressures are in the lower end of the pressure ranges. I'd stay clear of reindexing TBs ATT.
Just noticed your fluid temp is 158F, pretty warm! I'd expect that could be influencing your pressure readings.

I am prepping to replace my coils. What's the benefit of adding the spacer? What's the process of adding it and any particular place to get them?

 

[PabloCruise]

I am prepping to replace my coils. What's the benefit of adding the spacer? What's the process of adding it and any particular place to get them?

The spacers give your coils a little more lift. Hopefully I am using correct language, this would lower the pressure on your rear circuit.

 

[PabloCruise]

I got some time to look at my height sensors today and adjusted, but now I believe I am too low when I measure heights and compare to your notes for factory heights.
As you have said, it is an iterative process, but I am getting closer.
More later...

When I say "today" up above, it was actually early April when I got to this...
So far I had adjusted cross-leve at the t-bars, but then I went a little out of sequence due to my ignorance of how to properly set levels. Instead I skipped to setting front pressures with torsion bar adjustment, and then stuffed 30mm spacers in the rear.
Before we went on our last trip, pressures looked good, but my L & R front sensors were off; R was ~ +3 and L was ~ -7.
So I thought I would zero everything out and start from there...
First screen shot show me adjusting the height sensors as close as I could to 0 w/ engine off, but IGN on.
Then I cycled the AHC from N to L to N again to sudy pressures. Interesting that the height sensors did not return 0 values again, but 1mm is less than 0.04, less than 1/16".
Pressures look good, but the vehicle height came in a little low - I failed to record actual heights, but I would like to try the measurement described in the FSM and the corresponding math to set heights.

 

[PabloCruise]

Now that the trip is over, and I have some time to play with this more, I will unpack everything and take a look at the truck...

Do I still have cross-level?
How are heights front and rear?
Now that I have seen the FSM height sensor adjustment, I can adjust those.
Then adjust torsion bars for 6.9 Mpa up front and see what the rear pressures are. Maybe play with rear height sensor a little if it will help rear pressures. Rear sensor is pretty darn close to 0 as is.

I may start with air bags in the rear, just because I need one more thing that is adjustable to fuss over in my life...

Got some time to play with things today...

• Cross-level? Check
• Front height: 19.7", Rear height: 20.5"
• Sensors adjusted to deliver heights and w/in 1.8mm across F L & R
• Torsion bars adjusted so front pressures = 6.9 Mpa, Rear pressures over spec at 6.9 Mpa

Looking at the rear bump stops, I am not sure about making air bags fit in the stock AHC coils.

Does anyone know if air bags can manage the change in height/volume from N to H inside stock coils?

It seems like the King KTRS 79 coils might b my ticket: King Springs Suspension Standard Rear Springs KTRS-79 fits Lexus LX 470 | eBay

If I am reading @PADDO math correctly, the 30mm spacers I have in there are giving me ~0.6Mpa of relief on pessure, and the King Spings might offer anywhere from 2.5 to 3.5Mpa of relief in pressure. 6.9 + 0.6 - 3.0 = 4.5Mpa after the Kings. This would be out of spec to the low side, but I might be able to add some pressure back in by adjusting the rear height sensor.

The above work was done with full tank of fuel, I was out of the truck, no 3rd row seats installed.

I also measured my 16" wheels pretty carefully so I could measure heights from the bottom of the rim up through the center cap to the wheel opening lip. My 16" wheels measure 17 & 5/16", so I would subtract off ~8.65" from each measurement.

 

[Harp123]

Got some time to play with things today...

• Cross-level? Check
• Front height: 19.7", Rear height: 20.5"
• Sensors adjusted to deliver heights and w/in 1.8mm across F L & R
• Torsion bars adjusted so front pressures = 6.9 Mpa, Rear pressures over spec at 6.9 Mpa

Looking at the rear bump stops, I am not sure about making air bags fit in the stock AHC coils.

Does anyone know if air bags can manage the change in height/volume from N to H inside stock coils?

It seems like the King KTRS 79 coils might b my ticket: King Springs Suspension Standard Rear Springs KTRS-79 fits Lexus LX 470 | eBay

If I am reading @PADDO math correctly, the 30mm spacers I have in there are giving me ~0.6Mpa of relief on pessure, and the King Spings might offer anywhere from 2.5 to 3.5Mpa of relief in pressure. 6.9 + 0.6 - 3.0 = 4.5Mpa after the Kings. This would be out of spec to the low side, but I might be able to add some pressure back in by adjusting the rear height sensor.

The above work was done with full tank of fuel, I was out of the truck, no 3rd row seats installed.

I also measured my 16" wheels pretty carefully so I could measure heights from the bottom of the rim up through the center cap to the wheel opening lip. My 16" wheels measure 17 & 5/16", so I would subtract off ~8.65" from each measurement.

View attachment 1446992

I have been running air bags in my 2006 LC for over a year. I have a very tongue heavy 21'ft boat, and I installed new stock AHC coil springs and the bags. I have not towed in HI AHC setting but if I air the bags to 29 PSI in N setting, it raises the back up close to the H setting. I hope this helps and if need be I can check mine in high and go full on the bags.

 

[PabloCruise]

I have been running air bags in my 2006 LC for over a year. I have a very tongue heavy 21'ft boat, and I installed new stock AHC coil springs and the bags. I have not towed in HI AHC setting but if I air the bags to 29 PSI in N setting, it raises the back up close to the H setting. I hope this helps and if need be I can check mine in high and go full on the bags.

Thank you! Have you looked at your system pressures while the boat trailer is hooked up and you have pressure in the bags?

My concern is that if I installed bags, and then went wheeling with the system in H, would my bags get all buggered up inside the coils when I try to go back to N.

Did you modify your bump stops before putting the bags in?

Do you recall what size bags you went with?

 

[Harp123]

Thank you! Have you looked at your system pressures while the boat trailer is hooked up and you have pressure in the bags?

My concern is that if I installed bags, and then went wheeling with the system in H, would my bags get all buggered up inside the coils when I try to go back to N.

Did you modify your bump stops before putting the bags in?

Do you recall what size bags you went with?

No I have not looked at my pressures with trailer hooked up and air in the bags. I don't have the software and/or hardware. That is why I ordered new stock springs when I installed the air bags (to help with pressures when not loaded. For the front, I just turned my torsion bars 2 turns. I need to check them.

The airbags are very thick and I have not had any issues with damage, but as I said I have not wheeled in HI with the airbags fully inflated.

Bump stops were removed during installation, the air bags always have 5 psi in them so they are in a way a bump stop when the spring is compressed enough.

Airlift 1000 is the air bag I installed.

Sounds like for your application you would need to install the on board compressor and you can deflate before coming back to N.

 

[2001LC]

Can anyone steer me to some good 30mm spacers?

 

[trdcorolla]

Can anyone steer me to some good 30mm spacers?

I used item number SOF1133 from Slee: Slee - Toyota 80 Land Cruiser Suspension Spacers

 

[2001LC]

Thanks @trdcorlla. Anyone else?

 

[PabloCruise]

Can anyone steer me to some good 30mm spacers?

I think Iron Man supplies these with their lifts? My friend had a set left over...

 

[camino70]

Can anyone steer me to some good 30mm spacers?

I installed some, but didn't get much change in pressure. I should have gone with King springs.