Need someone to post Torsion Bar adjustment

[lexi4darin]

Hey guys, I've read a few of the old posts that cover AHC, torsion bar tightening and such. I'm planning an AHC flush (found lots of good docs on this, thanks everybody) and a torsion bar adjustment to level the front end that leans left (lots of good docs too). The problem with the torsion docs are many had pictures that were no longer being hosted and thusly, I haven't yet seen which bolt to adjust for the torsion bar.

I really need someone to post a pic or two that show the torsion bar and the adjustment bolt.

Comments welcome too. Heck, I'm not planning the neutral test this weekend so many of you may flame me. I simply don't have the Toyota/Lexus pressure tool (looks like forum members say it was too expensive and even no longer offered?); if someone has a work around and/or a suggestion, please let me know. Also, it would be great if someone pointed me to the right reference for this procedure for the future.

 

[Trunk Monkey]

Search

https://forum.ih8mud.com/100-series-cruisers/392604-dumb-question-about-t-bars-laugh-newbie.html

 

[Liam]

people people people......it is easy.

1. take your skid plate off so you can get access to the two bolts on the front of the T-Bar bracket.
2. Lift your tire off the ground and remove it.
3. loosen the adjusting bolt on the back of the T-bar just about all the way out. Leave about 1/8 - 1/4" of the thread showing at the adjuster nut. You will notice you will have a ton of slop between the adjuster arm and the adjuster bolt. (THis is the slack you will be taking out so the adjuster bar sits further down on the adjuster bolt) Make sense??
4. now all the load will be taken out of the T-bars and now take the two nuts off holding the T-bar "sleeve" to the control arm.
5. slide the "sleeve" off the T-Bar so that it hangs freely and it is not touching any of the threads.
6. Now turn your T-Bar in the direction that lowers the adjuster bar (in the back) on to the adjuster nut. It is easier to do properly when you're under the truck.
7. Once it is seated properly on the adjuster nut slide the "sleeve" back on the threads of the T-bar and on to the two bolts on the control arm. Check to see if the adjuster arm is sitting on the adjuster nut, if it is not you need to take the "sleeve" off again and readjust. I wanted to shoot myself because i finally figured out you can check the indexing without bolting everything together first......i had to do it 4 times on the DS before i figured it out.....the PS was a cake walk.
8. DO NOT PUT YOUR WHEEL BACK ON YET....after everything is bolted back together tighten your adjusting bolt at the back of the T-bar so that over an inch of the threads are above the adjusting nut.
9. put your tire back on but do not lower it to the ground just yet.
10. Crank your adjusting bolt more and then lower the jack and measure from the hub to the bottom lip of the fender
11. you might need to jack up the tire again and readjust until it is even on all sides.

Basically what reindexing the T-bar does is lower the adjusting bar lower on the adjusting bolt...thus giving you more usable threads....


hope this helps

 

[lexi4darin]

Trunk - thanks. my search failed. kept getting results that showed broken images. and in my defense your link produced a Nissan.


Liam, one only needs more threads if they're adjusting the truck a lot right? My truck is leaning to the driver's side 5/8" - 3/4". As a starting point I'm planning on bring the left side up 1/4" and passenger down the same amount. Don't think I'll need to follow your procedure for more threads. Is there a benefit I'm not seeing?

 

[agaisin]

My truck is leaning to the driver's side 5/8" - 3/4". As a starting point I'm planning on bring the left side up 1/4" and passenger down the same amount.

Fyi - according to the FSM "...adjust the torsion bar spring so that the difference between right and left in vehicle height is less than 10mm (.39in)."

A 1/4" difference seems well within spec and maybe even questionable that there is a difference unless you're 100% certain you're dealing with a perfectly level surface side to side and front to back... And tire pressures are 100% same, and gas tank is full, and no uneven weight distribution in the car, etc.

Anyhow - if you can get everything perfect more power to you! But according to the FSM, 1/4" would be well within spec.

 

[re_guderian]

I "think" he's saying the difference from one site to the other is 5/8-3/4", not 1/4", and above the 0.4" spec. Liam's instructions work well for re-indexing a LC's TB. I don't know if there is anything additional you need to do for the AHC system on the LX. Unless you're out of threads, you shouldn't even have to re-index, but again I know nothing of the AHC sensors/locations/adjustments, etc.

 

[lexi4darin]

I "think" he's saying the difference from one site to the other is 5/8-3/4", not 1/4", and above the 0.4" spec. .

You got it. I'm definitely off more than half inch. Been measuring for the last 2-3 weeks and the LX driver side is always at least 1/2" lower. Was off a full inch the other day on ground that wasn't too flat. Typically I'm 5/8-3/4" lower on driver side.

My point about 1/4" was to lower the "high" side and raise the low side. Thought this might make better sense with the AHC system. IIRC, read that here on Mud.

 

[agaisin]

Oops - I misread. Thanks for clarifying.

 

[uHu]

You do not mention the age of your truck (maybe put it in the sign.)

Anyhow, it is probably not advisable to lower the high side, just crank up the low until even. That is: Even after a trip around the block (or yard if you have the space).
The Torsion Bars do sag, weaken, so they should never be adjusted lower, unless they've been tightened too much previously.

 

[sleeoffroad]

AHC - Auto Height Control. The height of that truck in stock form is controlled by the AHC system and the adjustment of the sensors. Adjusting torsion bars is not going to do anything. Truck will just lower itself again. AHC trucks torsion bars can not keep the front end up, even if fully adjusted.

 

[OregonLC]

Two comments: 1) it's easiest to do if you put a paint mark on the t-bar/front bracket interface before you slide the bracket back. This will help tremendously when counting the number of teeth you've rotated. 2) get the truck aligned; you've just changed the front-end geometry and your camber and castor will be off.

 

[lexi4darin]

OregonLC thanks. An alignment is on the agenda.

uHu - very good point. 2000 with 140k I'm getting an order ready with Sewell Lexus (great guys, they do a lot of parts at discount for ClubLexus members, not cross promoting other forums just spreading the knowledge).

I think there's a problem with my driver side rear coil spring. Looks like the seat and hat for the coil spring have degraded and are coming apart. I'm planning to at least replace these (L/R) and the coil springs.

 

[DallasCrzr]

Sewell is def the s*** for those of us from dfw, our family buys all our cars there

More on subject it would be great if there was a write up like Liam's above but with pics...or at least pictures with the different parts labelled

 

[RPMLX470]

Attached are some procedures for making height adjustments with a Lexus Scanner and w/o scanner using a pressure gauge. Although most of us don't have these tools, there are some specifications and illustrations that might come in handy..

 

[mgeiger]

I've read a dozen threads on the subject, but a pic is worth... So are there pics of this process on a non-AHC vehicle? I suppose both sides are cranked (raised) by turning the 30mm adjusting bolt CLOCKWISE? but I'd rather know for sure.

 

[lexi4darin]

Basically you got it. I can post a pic or two of my FSM tonight (2000 LX470 though).

There should be a basic write up on this but I haven't seen anything other than the AHC Sus Height Adjust pdf above.

I resolved my issue this last weekend. 2 steps did it for me: torsion adjusting and level sensor adjusting. Not included in the steps is a fluid flush of the AHC system, which I performed a couple weeks ago. And I still need to figure out how high the pressure readings are but i'm not sure how this is performed without the Toyo LSPV tester.

 

[uHu]

AHC - Auto Height Control. The height of that truck in stock form is controlled by the AHC system and the adjustment of the sensors. Adjusting torsion bars is not going to do anything. Truck will just lower itself again. AHC trucks torsion bars can not keep the front end up, even if fully adjusted.

Here we are talking about adjusting the lean. Not lifting or lowering.
The AHC pressure is always the same on left and right (as long as the steering is straight). Therefore, a left-right lean is adjusted by cranking the T-bars, - and that is according to the book as well.

Two comments: 1) it's easiest to do if you put a paint mark on the t-bar/front bracket interface before you slide the bracket back. This will help tremendously when counting the number of teeth you've rotated. 2) get the truck aligned; you've just changed the front-end geometry and your camber and castor will be off.

Re 1: That's for re-indexing only, lexi4 is just cranking away the lean to the left.
Re 2: By getting the truck back to level, the front end geometry will be better than before the leveling. Unless no other factors, no need for adjusting geometry.

...I think there's a problem with my driver side rear coil spring. Looks like the seat and hat for the coil spring have degraded and are coming apart. I'm planning to at least replace these (L/R) and the coil springs.

Did you change the coils and seat?
If you get it level by turning the left TB, and the L-R lean changes when you change the coils, you can crank the TBs again. Difficult to say how much to turn without measuring the ahc pressure, but likely to be several turns. The pressure is, as mentioned above, the same on left and right; and the TBs will have to compensate for any difference in weight on the two sides. (We know that the truck is heavier on the left)

...I resolved my issue this last weekend. 2 steps did it for me: torsion adjusting and level sensor adjusting. Not included in the steps is a fluid flush of the AHC system, which I performed a couple weeks ago. And I still need to figure out how high the pressure readings are but i'm not sure how this is performed without the Toyo LSPV tester.

Which sensor did you adjust, and why?

You can measure the ahc pressure with any gauge which can take about 1000 psi, as long as you can get it attached to the actuator through the bleeder with a 7mm adapter. See eLeclerc's thread.

 

[lexi4darin]

uHu -


That's just it. My method was one of madness (j/k). But I got most of the lean out of the truck with the torsion bars a couple weeks ago. Then it seemed to creep back in. Last weekend I looked at the truck and noticed the front end was raked a bit beyond the stock rake of 1".

So I looked at all 3 AHC sensors. Rear looked fine. DS front was at the lowest setting; PS front was at a higher than neutral setting. Not understanding the proper procedure for measuring the volts (apparently this is comparable to getting the pressure readings?), I went with the safe play. I moved both front sensors to the high setting to equalize them. This plus the torsion bar adjustments from the prior week brought the truck to within a 1/16th at every corner. It also eliminated the rake completely so I raised the rear sensor a little to equal about a .5" rake. Probably should have lowered the front sensors but I have no idea of how to do this equally other than the eyeball test. If this sounds like madness, let me know.

Right now the truck results are spot on level, with regards to lean, and has .5" rake towards the front. This is tested over several days now. My only issue would be with unknown pressure levels.

Making the 7mm adapter isn't an option, wiith no welding ability I don't know how LX owners are supposed level and check pressure. I've been through several posts and it's confusing a bit. My FSM's finally came and of course they reference the Toyo LSPV tester tools...I noticed that one Mudder used the Wakeo (sp?) kit but for over $300 I don't know if it's worth it.

 

[lexi4darin]

Also I tried searching for eLeclerc's thread in the Hundie forum. No results.

 

[hoser]

It's "eleblanc"