First Bought a UZJ100: 1998 LX470, 198K mi. Failed AHC. Suspension Advice Needed.

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MauiUZJ

Gotta have duct tape...
Joined
Dec 26, 2016
Threads
4
Messages
203
Location
Maui, Hawaii, USA
So this is my first post, and my first UZJ100. So far I am feeling a bit like it is a mixed bag.
Body is great, other than scratches on the running boards, a missing LEXUS emblem, and a few superficial finish blemishes. First owner babied it, and kept it in a garage. Second owner wheeled it up on Haleakala Ranch, and all over the mountain, until the AHC failed.... He paid $1850 for a local suspension shop to "do their best" at making it ride at about the level of Norm. on the AHC. Replacement suspension feels very stiff to me, on the small country roads around home on the north shore of Maui. Uncomfortable compared with my last LC, an FJ80. The IFS Handles nicer on the highway than the SFA, and the road feel around smooth corners is excellent, but moderate speed (25-35) over poor paved road surfaces is uncomfortable.
The new (to me) Truck has OME Nitro-charger Sport shocks all around, OME 1" medium duty coils (865's I think) in the rear, Factory torsion bars up front. Unfortunately front torsion bars are 25.5mm, so they are softer than the LC 28.89mm, and the OME's at 31mm, etc.
TB's are either re-indexed or just cranked up, to clear the 33's.
Ride height measurements are roughly 20" front, and 22" rear.
I will get better measurements and measure droop
on some level pavement soon.
I thought I had better check tire pressure to make sure they weren't too high. They were all 27psi...
Hate to think what the ride would feel like at 40psi....

I knew this Lexus was in need of considerable maintenance before buying it, however it was the only UZJ100 in the state for less than 10k. For starters it had failed rear u-joint, a failed alternator and a dead undersized battery the same size as my wife's previous RX300 calls for. It leaks Oil at the valve covers and the oil pan. Sway bar bushings are dead, & one is half gone. Right CV has a torn inner boot and makes noise under moderate acceleration and cornering. Turns out the original Timing Belt was roughly 108K overdue.... Thank GOD the rear u-joint failed & they stopped driving it when they did....

I replaced the Alternator, Aisin Timing Belt Kit w. the water pump, tensioners and the front main seal. I was working outside on muddy grass and the weather began to shift for the worse, so I put it back together without changing the cam seals, or valve cover gaskets, or spark plugs I had on hand while I was in there. I Will need to change the radiator soon as I can see stress cracks on the top that are just beginning to seep, but for now I slit the inner gasket of the cap to run the cooling system at 0psi, to minimize stress on the cooling system until I can install an aluminum radiator, thermostat (I only put a FAIL-SAFE Thermostat by MotoRad into cars my wife will drive), the main hoses, and all the heater hoses etc. next round....

I need to keep this truck on the road as much as possible and minimize down time as it is the new family DD, & adventure truck. As the new all around family vehicle it needs to be comfortable for all passengers, especially my wife. She tolerant of Land Cruiser suspension tech having grown up with an 82 Hilux, and as a former owner of an FJ60. She even put up with me dragging her and our 2 girls 6000 miles across North America and back in the FJ80 summer of 2015.

I think the current ride height has put additional strain on the front drive train and caused the torn CV boot/ failed axle. There are some dead looking bushings on the front diff, so i am guessing the driveline clunk is mostly in the front. I am going to pull the front driveshaft and run it CDL Locked, in "2wd" with the just the rear Posi for a week or so to see what it would feel like with a part time 4wd kit. Also I think this will help me narrow down if the drive line clunk is in the front, rear, or both. One day i plan to do a front diff lock to prevent failure of the 2 pinion front diff, and add traction at the same time. Bet replacing

I have read through a half dozen threads so far, and I am still not sure what is the right setup for us. We are generally running stock and light (5400lbs according to the registration), but everyday onroad (read small East Maui country road) conditions on Maui can be rigorous, and all winter we have extreme weather to drive through, then in summer we have hurricanes. I have had to cross deep standing water, traverse downed trees, and mudslides, just to get home on a bad day. Any given nice day we may go ramble down some gnarly jungle mud trail to visit a waterfall, or wheel across old lava to get to a remote beach, or go the back way to Hana across mile of washboards. Once my friend who sold me this LX replaces it with a LC100, I hope to ramble up on the mountain with him.

I am unsure as to plan to upgrade the current lift with a diff drop kit, SPC UCA's, OME front torsion bars, and a new set of fox 2.0" shocks all the way around, so that I can get them re-valved if needed.
I like the way the current setup looks, although it is a little high in the rear at the moment. I thing about 1" rake would be better. Will the OME springs and TB's be OK with Fox's ?

I know stock Landcruiser springs and stock LC height would be OK with the wife. A set of OEM or KYB shocks would give good on road ride, but for these to work I need heavy bulky used parts that are unavailable on island....

Got to get it riding better as the first priority for the wife. this was supposed to be her vehicle, but as of yet she is shaking her head....
 
Welcome! It sounds like you know what you're doing and are well-read on these trucks. I'd start with stock LC front shocks and the diff drop while putting some feelers out there for some used OEM LC torsion bars. I would guess you could get them nearly free, pay shipping to Maui, and they'd still be cheaper than buying OEM. Buy the OME ones if used ones don't work out. I think that'd give you the best ride while keeping your lift. I'd then start going through all the bushings, boots and ball joints to work out the squeaks and rattles before messing wth new UCAs.

I don't have any first-hand experience with the Fox 2.0s, but have read mixed reviews here.

You probably don't need valve cover gaskets. A quick tightening solved my drip.
 
Thanks for the welcomes guys,

@labcab: thanks, For the tip. The valve cover bolts were finger tight. Got them snugged up. Leak may be stopped now. At least it is way slowed down. Not going to miss the smell of oil burning off the exhaust manifolds every time I fire it up.... I will be looking at stock LC shocks for the front. I think the amount of preload on the skinny AHC TB's is part of the poor ride.

Yes I've been reading up on the truck. After I dragged it home, & worked on it all weekend it was sure a disappointment to load up the family & take it for a drive.

My wife looked at me like I was crazy for paying 4k for this truck. Between the missing sway bar bushing and the front axle, it goes Squeek, clickety clickety clickety, slap around an uphill off camber 15mph corner I travel frequently....

I would like to get it to ride at least as good as our previous 80 series did with Monroe Gas-Magnums all around and good tight bushings.

I like the height it is at now, & so does the wife. I will be seeking stock used take off front TB's to try. I think the diff drop is necessary at the current height, or I will go through front axles more often than I would like....

I am a bit concerned that the rear OME springs will be too stiff even with different shocks. Also I am not sure stock LC shocks will be long enough for the rear with the OME springs. Maybe I should hunt for some stock LC rear springs as well, & stick them
In with a pair of 10-20mm trim packers.
 
If your ride height allows it, stock LC shock are very inexpensive new. That may free up some $$ for replacement rear springs and torsion bars.

Good luck
 
image.webp
 
@labcab I see you are running the same year LX with the same tires, a diff drop, and an OME suspension. Here are a few questions for you specifically. What front TB's are you running? Which OME components do you have? I realize this is subjective, but how is the ride in your truck? Is it heavier than stock? Thanks again for your advice.
 
@ aging fleet: Stock shocks will be fine up front as is I think, but I am not so sure about the rears. I need to get to a level parking lot to measure ride height again. My first measurements were in the yard more or less where the pic was taken. Measurements were 19.5" RF, 20.5" LF, 22.5" RR, 21.5" LR. The ground was a bit uneven, so my guesstimate's for ride height is just the average of the fronts & rears. 20" front, & 22" rear. It looks about 2" higher in the rear than the front, & feels noticeably higher in the rear when driving. Kind of stink bug. Not opposed to the lift. I like the look, the fit of the 33's, & I often need good clearance. I just want it to ride over the local country roads better than it does now. We have lots of paved roads that are worse than a good gravel road would be back on the mainland. It doesn't help that the asphalt patches wash out, and end up all over the road every other tropical rain storm.
 
I'd suggest the following from the lessons that I learned on my son's 2000 LC:

The AHC torsion bars are too light to support the truck on their own. I'd go with the OEM (non-AHC) torsion bars unless you are planning on additional weight up front. Your going to have to pay shipping whether it's for some OEM take-offs or OME from one of the usual suspects.

Get up under the vehicle and see if you can find a tag on one of the installed rear springs to identify which model of OME springs.

If you've pulled the 3rd row seats, put them back in. The extra weight seems to help with an otherwise stock vehicle and the OME 865 or 860 rear springs and OME shocks.

At 20.5" in the front, you're probably OK without the additional caster of aftermarket UCAs. If you're planning on adding another inch (21.5") your probably going to want the additional caster (and travel) of aftermarket UCAs.

The current OME shocks for the 100 series seem to be much stiffer than the old OME shocks that I had on my 80 series. Even with additional weight, they're better, but still seem excessively stiff. The OEM shocks are a heck of a deal compared to the aftermarket alternatives.
 
Thank you for the good advice jLB.

I had a feeling the AHC torsion bars were too light to support the truck properly. Tells me that at the current setting they must be under considerable preload.

I had pulled one rear seat. Will put it back in tomorrow.

I'll crawl under the back & check the spring models in the morning.

Found OME front torsion bars on Amazon with Free Prime Shipping for $308. Although I have to pay for the new bars, I may have them shipped for free. Worked on my replacement 8 ton ram for the engine crane and several sets of tires...

OEM used T-bars may be next to free, but shipping may be significant. $100-$200 I would guess. They are going to be softer.

I think that either OEM or OME TB's, and OEM type shocks up front will yield a more comfortable ride than the current setup.

Any idea if the OEM TB's up front at around 20.5" will be well matched to the OME springs in the back, with something other than OME Nitrocharger Sport shocks all the way around?

I hope to hear from someone running OME springs and TB's and OEM shocks or some other brand of aftermarket shock.

I have always had good luck with KYB shocks and struts. Did you mean OEM Toyota shocks or OEM type from aftermarket suppliers?

Maybe the medium duty springs in the rear will be OK with other shocks, and good when the truck is loaded up with gear. Especially when towing another car or 3 horse trailer. The LX will assume those occasional roles as the plan is to replace my 2003 Dodge Dakota quad cab pickup with the 4.7, tow package, & posi, and my wife's 1999 RX300 AWD with this truck and a trailer. Eventually there will be less maintenance and taxes on one machine, even if it is bigger and heavier, and had higher miles. Once I get one of the others sold I will be ready to purchase suspension parts...

Hoping to hear a few more experiences as I make the plan for the next phase of the suspension on this truck.

Aloha all from Maui,
Thank you for the help and tips as I get this LX470's ride quality worked out.
 
@labcab I see you are running the same year LX with the same tires, a diff drop, and an OME suspension. Here are a few questions for you specifically. What front TB's are you running? Which OME components do you have? I realize this is subjective, but how is the ride in your truck? Is it heavier than stock? Thanks again for your advice.

@MauiUZJ my truck is a 98 LC, not an LX, but from what I've read, that shouldn't make a difference from a parts compatibility perspective.

For roughly the past decade, I've been running the 2.5" medium-load Slee kit. I installed this kit with plans to add more weight (bumper/winch/drawers), but life got in the way and those upgrades never happened. I never minded that it rode stiff, but the wife had some opinions on it and I started paying attention once a newborn was riding in the back. Over time it also got noisy. We recently picked up a '11 LX, and the LC feels like it doesn't even have springs compared to the ride of the LX.

I recently went back to OEM shocks in the front when I did front rotors and bearings. The wife asked if I changed something the first time she rode in it. It is a noticeably better ride with only swapping the front to OEM shocks.

I agree with @jLB above. If you are also adding a bumper/winch, get the OME TBs, and try your Nitrocharger shocks before buying anything else. If you're not, get Toyota LC TBs and shocks. The LX TBs are too light for that truck without the assistance of the AHC.

I will be going back to OEM shocks on the rear when I do some other stuff back there in the spring. In retrospect, I would have kept my OEM suspension, added the rear spring spacers, diff drop, and cranked the TBs. Then upgraded components only if the ride deteriorated after weight was added.

I agree with your plan on the rear. The heavier springs and shocks back there will help for towing. I believe the consensus on here is to add $80 air lift bags to the rear for frequent towing. They are cheap, easy to install, and keep the rear from sagging under heavy loads.
 
@ LabCab I bet the newer LX rides extremely nice. I bet this one ride really good until the accumulators lost enough charge and the diaphragms ruptured. Would have been great if KYB or Lexus had engineered them to be a serviceable item with a nitrogen refil port of some sort. Then every 5 years or so you could have them recharged.

Thanks for the advice on this one. I am going to begin seeking stock front TB's ASAP, & I can tell I need to get a diff drop kit shortly thereafter.

Going to keep the rear as it is for now. Will consider OEM Toyota LC shocks if the will work with the lifted rear ended down the road a bit.

Weather was good today, so I got out the service ramps and crawled around under the truck to poke around.

@jLB Rear springs are OME 860's.

Front TB's were cranked just about as far as the bolts would allow....

I think the front being under sprung, over tensioned, & heavily dampened is the main cause of the poor ride quality.

image.webp
 
Decided to back off the TB bolts some as I read in another thread they can be damaged by cranking them way up, & Toyota does not manufacture replacements.

Ended up cranking them down 10 revolutions just to see what that would do. Thought I only took the front down from 20.5 to 19.5" up front, but after some driving it settled down to 18". On the plus side Front Axle noise went away. Truck rode a little less bouncy up front, but castor was off, & it wanted to dart back and forth a little.

4" rake gave it the extreme stink bug stance.

image.webp
 
Going to crank it back up 1" or so for now. And going to begin searching for some used TB's.
 
You don't adjust the height with the torsion bars, you adjust the height with the height sensor if you have AHC. I would do some reading up on this system before playing with it, the torsion bars can balance the side to side difference and are used to set the pressures in the system..Your AHC might be good, just setup wrong.
 
Sorry didn't read the AHC had been ripped out. Yes the OEM AHC Torsion bars are not designed to carry the weight unaided. Either reinstate the AHC or fit non AHC torsion bars. Did the previous owner keep the AHC parts they took off?
 
The question as to the adequacy of AHC (25.5mm) torsion bars being left in service after the AHC system has been gutted, instead of replacing them with the correctly rated bars (28.8mm) - or heavier if going aftermarket - often comes up. Here's some fun facts regarding the engineering behind torsion bars. All else being equal if you double the thickness of a torsion bar you increase its rate by 16 times so that extra 3+mm in diameter the conventional torsion bar has over the AHC bar provides significantly more effective torsional force - about 60% more actually. You can go to a site such as swayaway.com and in their Tech Room they have a cool TB rate calculator. Using conventional LC bars at 1.13in v AHC bars at 1.0inch (bar length and lever arm lengths are arbitrary as we're just looking at ratios) you'll see that the thicker bar provides approx. 60% more effective torsional rate at the front wheel. Working on the premise that Toyota's design engineers had big brains, plenty of time and billions of yen I'd like to believe they chose torsion bars appropriately rated for their respective applications. Accordingly anyone who seriously believes they can just reindex underrated AHC bars in a non AHC application and get away with it in the long term will ultimately be disappointed.
 
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