2011 LX570 sensor lift + spacer - sense check before I wrench

[Grumvee]

Hi folks! Been mining the AHC threads here (thanks especially to the Augmenting for Load and Height Modifications threads - most of this plan comes straight from them).

My truck: 2011 LX570, 172k miles, AHC/AVS, no KDSS. Falken Wildpeak A/T4W LT285/70R17 Load Range C on Icon Vector 5s. Slee sliders, Prinsu rack, drawer system in back. Payload runs rear-biased: gear, drawers, hitch-mounted dual dirt bike carrier on weekends, family trips with 4 people. Loaded trips pencil out at 1,200 - 1,400+ lbs of payload. 90% on road, 10% off road (some technical).

AHC history: Flushed at 147k. Globes are original. Planning to flush again in the next 5k miles.

The plan after service:

1. Sensor lift: ~1-1.25" front, ~0.25-0.5" rear. Keeping some residual rake so it sits level loaded. Techstream HOU to fine tune, zero point and G-sensor reset, retorque at new height, then alignment.
2. OEM front top-hat spacer (43136-60020) for droop and front pressure margin.
3. Rear coil spacer sized per the "sensor lift + 10mm" rule of thumb.
4. Possibly new rear bump stops (originals are 15 years old).

Not doing airbags for now. Not doing panhard correction, extended links, or brake lines at this height.

Where I'd like a sense check:

1. What size rear spacer, and does it matter that I can't find much between 15mm and 30mm? The formula points me to right around 20mm, but the off-the-shelf poly options I'm finding are 15mm (Dobinsons PS59-4006, SuperPro SPF3287-15K) or 30mm. Is 15mm enough for a sensor-lifted truck carrying 1,400+ lb rear-biased, or do I need to go 30mm and deal with the consequences?
2. What are people actually buying and installing? Seeing a mix: Dobinsons 15mm poly cross-fit from the 100-series, SuperPro, generic eBay aluminum in 20/30/40/50mm that needs the ID machined for the bump stop taper. Anyone found a clean 20mm-ish rear spacer that fits the LX570 cone bumper without modification? Also - Dobinsons says do not stack their spacers, but I've seen 2x10mm stacked here with one above and one below the isolator. Which is right?
3. Coil bind and bump stops. Dobinsons warns that spacers can bring on coil bind before the bump stop engages. At what spacer size does this actually become a concern on a 200, and does it change what bump stop I should run?
4. Anyone actually carrying 1,400+ lb on a sensor-lifted truck with spacers only? I've seen 1,800-2,200 lb numbers cited, but I think those setups are running airbags as a helper. Trying to figure out what spacer-only realistically supports before H-mode gets flaky.
5. Globes are original at 172k, no leaks, transitions feel normal. Is there a way to assess them short of replacement, or is age alone the trigger?
6. Anything in this sequence you'd change? Especially interested if anyone's hit the over-spring problem (too much preload, mushy damping, Low mode issues).

Thanks for your advice!

GRUMVEE

 

[TeCKis300]

Hi folks! Been mining the AHC threads here (thanks especially to the Augmenting for Load and Height Modifications threads - most of this plan comes straight from them).

My truck: 2011 LX570, 172k miles, AHC/AVS, no KDSS. Falken Wildpeak A/T4W LT285/70R17 Load Range C on Icon Vector 5s. Slee sliders, Prinsu rack, drawer system in back. Payload runs rear-biased: gear, drawers, hitch-mounted dual dirt bike carrier on weekends, family trips with 4 people. Loaded trips pencil out at 1,200 - 1,400+ lbs of payload. 90% on road, 10% off road (some technical).

AHC history: Flushed at 147k. Globes are original. Planning to flush again in the next 5k miles.

The plan after service:

1. Sensor lift: ~1-1.25" front, ~0.25-0.5" rear. Keeping some residual rake so it sits level loaded. Techstream HOU to fine tune, zero point and G-sensor reset, retorque at new height, then alignment.
2. OEM front top-hat spacer (43136-60020) for droop and front pressure margin.
3. Rear coil spacer sized per the "sensor lift + 10mm" rule of thumb.
4. Possibly new rear bump stops (originals are 15 years old).

Not doing airbags for now. Not doing panhard correction, extended links, or brake lines at this height.

Where I'd like a sense check:

1. What size rear spacer, and does it matter that I can't find much between 15mm and 30mm? The formula points me to right around 20mm, but the off-the-shelf poly options I'm finding are 15mm (Dobinsons PS59-4006, SuperPro SPF3287-15K) or 30mm. Is 15mm enough for a sensor-lifted truck carrying 1,400+ lb rear-biased, or do I need to go 30mm and deal with the consequences?
2. What are people actually buying and installing? Seeing a mix: Dobinsons 15mm poly cross-fit from the 100-series, SuperPro, generic eBay aluminum in 20/30/40/50mm that needs the ID machined for the bump stop taper. Anyone found a clean 20mm-ish rear spacer that fits the LX570 cone bumper without modification? Also - Dobinsons says do not stack their spacers, but I've seen 2x10mm stacked here with one above and one below the isolator. Which is right?
3. Coil bind and bump stops. Dobinsons warns that spacers can bring on coil bind before the bump stop engages. At what spacer size does this actually become a concern on a 200, and does it change what bump stop I should run?
4. Anyone actually carrying 1,400+ lb on a sensor-lifted truck with spacers only? I've seen 1,800-2,200 lb numbers cited, but I think those setups are running airbags as a helper. Trying to figure out what spacer-only realistically supports before H-mode gets flaky.
5. Globes are original at 172k, no leaks, transitions feel normal. Is there a way to assess them short of replacement, or is age alone the trigger?
6. Anything in this sequence you'd change? Especially interested if anyone's hit the over-spring problem (too much preload, mushy damping, Low mode issues).

Thanks for your advice!

GRUMVEE

In your assumptions
1. Rake is not important to AHC. It's constant height so even with load, it does not droop.
2. For that lift, get the 13mm E&E spacers - 13mm Top Hat Spacers | E&E Off-Road - https://www.ee-offroading.com/product-page/13mm-top-hat-spacer
3. As you'll have more installed weight (drawers), going over 10mm extra isn't a big deal. I'd assume more rear sensor lift, and 15mm extra margin for installed weight, and use 30mm spacers. Alternatively, 15mm spacer in the coil, and 10mm spacer above the jounce stops.


To your questions
1. Go for 30mm, and .5" to .75" of rear sensor lift.
2. Been too long and the suppliers may change, so it's kind of luck of the draw. In the many I've tried, about 30% of them need ID machining
3. Coil bind is not an issue for the light AHC springs
4. I'm no longer using airbags as they don't like the high speed desert running I do. 2200lbs payload no problemo. IIRC, I'm on 40mm spacer (30mm in coil, 10mm spacer above jounce stop) with fresh new OEM rear AHC springs
5. Just replace them at that mileage. For as cheap as they are (Ebay Japan seller), and how easy they are to replace, get her done for another great decade of goodness