Does the 22mm bolt to adjust torsion bars face the rear of the vehicle?

[Weeniewheeler]

Simple enough, right? I need to adjust the driver's side height of my truck in the front. it is down over an inch to the passenger's side. I read and search here and understand that putting more twist in my torsion bars should accomplish this. AHC is working correcctly with over 10 gradations from low to high. Unfortunately, the FAQ that everyone points to with the wonderful picutures doesn't have any photos for me and never has had. I climb under the truck and locate the back end of the TBs which go into a cradle of sorts and find a 22mm bolt head to crank, but I cannot see how this bolt will tension the TB. I'm frustrated as hell, because I can't seem to get any vendors to talk to me about suspension options, and I'm trying to fix what should be a simple issue and I don't know which $@#%^ bolt head is the right one. So, does that 22mm bolt face the rear of the vehicle?

 

[bctlex]

Did you see the pdf on post #106?

For those with torsion bar questions

 

[Weeniewheeler]

Thank you! I didn't get to post #106 because I got too frustrated with not seeing pics. I was referring to "A" which doesn't do anything. "B" is the adjuster, as I suspected. It is a lot bigger than 22 mm. Not sure where that number came from. Thanks again for pointing that out. I feel like an ass for missing that, but at least I can adjust the right bolt.

 

[PADDO]

Its 30mm, one either side. If you've got to adjust out 1 inch then I strongly recommend you do this incrementally - tighten (cw turns) the drivers side probably 3 full turns and loosen (ccw) the passenger side the same amount. One turn on one side will change the height about 1/8 inch. Test drive and fine tune by adding/subtracting as necessary. You'll also need to check overall height (adjust sensors if necessary) then adjust (your now cross level vehicle) torsion bars equally for the correct pressures.

 

[Weeniewheeler]

3 full rotations and now she's dead level again.

 

[taco47001]

Thank you for this! I just noticed today that one is leaning to the drivers side. I have TechStream on the way and will tackle this as soon as I get it.

 

[Kross]

How important is it to jack the vehicle up before making height adjustments?

 

[Weeniewheeler]

I'm not sure, but the instructions I read said to do so, so I did.

 

[azzaLX]

Kross,
I have been working on mine and I only raise the AHC to high as it seems to be a bit easier to tighten the TB 30mm bolt...not having any problems and I am sure not doing any damage to the TB adjustment bolt....

Paddo,
Thanks for the info above. I am working on mine and doing as you described, however I am having one problem that cannot solve....pressure is too low based on the FSM (using tech stream). I have the cross level correct, correct vehicle heigh and the TB's are tightened just to the minimum as per FSM....but I get a pressure of about 6.0....in order to put the pressure at the correct level (6.9) I would have to loosen the TB's (to put more load to the AHC) but if I do that they would go below the minimum tightness as per FSM.
The possible causes I see are below....would you or anyone else have other ideas?
- TB's installed in wrong position somewhat....not sure this is possible
- FSM minimum TB tightness is wrong
- Pressure reading is wrong either the gauge in the vehicle or the tech stream?
- I am measuring the heigh wrong....I did it so many times that I am pretty sure it is correct as per FSM and vehicle looks OK.

I see no change in suspension behaviour when I move from comfort to sport...but that probably makes sense seen that TB's are doing most of the work....what am I doing wrong?

Rgds,

 

[PADDO]

How important is it to jack the vehicle up before making height adjustments?

For AHC vehicles the FSM says to do this job with the vehicle on flat level ground

 

[PADDO]

Kross,
I have been working on mine and I only raise the AHC to high as it seems to be a bit easier to tighten the TB 30mm bolt...not having any problems and I am sure not doing any damage to the TB adjustment bolt....

Paddo,
Thanks for the info above. I am working on mine and doing as you described, however I am having one problem that cannot solve....pressure is too low based on the FSM (using tech stream). I have the cross level correct, correct vehicle heigh and the TB's are tightened just to the minimum as per FSM....but I get a pressure of about 6.0....in order to put the pressure at the correct level (6.9) I would have to loosen the TB's (to put more load to the AHC) but if I do that they would go below the minimum tightness as per FSM.
The possible causes I see are below....would you or anyone else have other ideas?
- TB's installed in wrong position somewhat....not sure this is possible
- FSM minimum TB tightness is wrong
- Pressure reading is wrong either the gauge in the vehicle or the tech stream?
- I am measuring the heigh wrong....I did it so many times that I am pretty sure it is correct as per FSM and vehicle looks OK.

I see no change in suspension behaviour when I move from comfort to sport...but that probably makes sense seen that TB's are doing most of the work....what am I doing wrong?

Rgds,

Please post the fsm procedure you're using to adjust the TBs - to the best of my knowledge it is mutually exclusive to satisfactorily setting neutral pressures. I'm aware of two instances of guys attempting to do what you are and it just doesn't work. I've asked for this "TB adjustment procedure" to compare and contrast against the "AHC neutral pressure adjustment procedures" and haven't seen a copy yet, just one screen shot floating around on mud. I suspect the TB procedure you're using is for non AHC vehicles.
I recommend just adjusting the TBs for cross level, ensure front and rear heights are correct then set your front pressure with equal turns on both adjuster bolts. Address rear pressures with new coils and/or spacers.

 

[azzaLX]

Thanks for the reply. I am using the TB adjustment procedure straight out of the 2005 LX FSM, I have a hardcopy. Below the procedure, sorry for the image quality just took a picture from FSM. As of now I have the dimensions A very close to 8 and 2mm as per FSM which is the minimum and gives the least load to the TB's and still get pressure of 6...When I have a couple of hours free I will go thought the whole procedure again starting with confirming cross level, then vehicle height and check what pressures will be then.....let's see.

 

[PADDO]

What does your fsm say about AHC height and neural pressure adjustment?
If you just do those SA TB remove/install and set ups then you'll never get your AHC set up correctly. Go further on in your FSM (in mine it's around SA 313) and look at the AHC height and torsion bar adjustment for correct neutral pressure pages. Unfortunately I believe you're really making work for yourself. Regardless of what dimensions you achieve following those initial steps you will ultimately have to tighten/loosen the bolts as necessary to achieve the pressures outlined in subsequent pages.

 

[azzaLX]

Had some time to work on this....follow your recommendation and I ignored the SA TB installation measurements and followed the AHC/TB adjustment procedure for correct height and neutral pressures and managed to get cross level, heights and rake all within 1/2 inch or so. Front pressure is spot on but hear is a bit high, probably due to 10 year-old rear springs. Thanks a lot!

 

[CanadianRockyCruiser]

Had some time to work on this....follow your recommendation and I ignored the SA TB installation measurements and followed the AHC/TB adjustment procedure for correct height and neutral pressures and managed to get cross level, heights and rake all within 1/2 inch or so. Front pressure is spot on but hear is a bit high, probably due to 10 year-old rear springs. Thanks a lot!

If you need a hand with this, let me know (PM me). I am in Calgary and have done mine a few times over the years.

 

[PADDO]

Had some time to work on this....follow your recommendation and I ignored the SA TB installation measurements and followed the AHC/TB adjustment procedure for correct height and neutral pressures and managed to get cross level, heights and rake all within 1/2 inch or so. Front pressure is spot on but hear is a bit high, probably due to 10 year-old rear springs. Thanks a lot!

Thanks for closing this out and glad you got things sorted out. A disclaimer on those TB pages advising those with AHC to proceed straight to the appropriate AHC pages wouldn't be out of place. As you found, following that TB set up leads to too low neutral pressure with the subsequent over sprung harsh ride. 30mm coil spacers should net you a drop in rear pressure of around 0.5MPa.
6.9MPa is the right target pressure for the front, but don't be afraid to tweak up or down to optimize damping. 6.9 is factory new, fully charged damper accumulators etc. As the dampers age and naturally loose nitrogen you might find the best overall damping occurs around 6.7ish. Likewise, I've found lower in the specified range is better for the rear too.

 

[azzaLX]

Thanks CanadianRockyCruiser. PM sent.

Thanks Paddo. Yes, I will be looking at the rear spacers....eventually want to do a modest lift, try and keep AHC and go up 1 or 2 tire sizes so will do it all together when time comes.