Inconsistent pressure reads from Techstream at AHC front (1 Viewer)

[OregonB]

TBs had never been touched on this LX, started with 7 turns and got a few readouts at the front averaging 7.4. Gave it three more turns to try to get down to spec range, & then it got wierd: 6.9, 6.3....then 3.0. Since then, I have been unable to get a consistent (more than two in row within 0.4) pattern. I backed off 1-1/2 turns and got a few 6.7s, followed by a 7.1. Loosen 1-1/2 turns and 8.2, 8.2, 3.0. Currently hovering around 6.5s to 6.9 and maybe I'll just call it good, wearing out my AHC, ha.
Is this an indicator of a problem - is it normal or should I be getting a tighter pattern?
(Accumulator has been steady at 10.5 to 10.4. Rears are consistently 8.5 - 9.7 range depending on what I'm doing at the TBs, plan on replacing springs to try to tackle those #'s.)
After doing any TB turns I do a short drive, maybe just to shake out anything from the adjustment. Have always noticed a bit of a shudder/thump at the front end when shifting N to Low and back to N, as if sticky. I'm just driving a few yards back and forth to activate AHC.
Fluid is at spec, was bled/changed about 20K ago.
Can't end w/out thanking the Mudders here & solid threads here that helped me to get the Techstream running ("Techstream in 5 minutes" did it).

 

[ramangain]

Sounds ok. Just check it in a month or so, or when you do the rear springs.

 

[OregonB]

Are H-N-L shifts typically a smooth lift, or is some small shudder to be expected? Never been in another LX to compare.

 

[LndXrsr]

Usually smooth, might make some small adjustments front to rear at the end, but not jerky.

 

[LXKevin]

In case anyone is interested in the stock height King springs i received this from them recently:

KING SPRINGWORKS +61 7 5539 6700 (Mick Stubbings Export Coordinator)
sales@kingsprings.com.au
KTRS-79 (Cost About $278.00 delivered to the USA)
AUD $226.00
DHL Freight
AUD $155.00

 

[OregonB]

Got the springs. I'll be putting them in shortly. I'm seeing mixed approaches on videos - some look like they're able to replace very quickly (maybe this is only on LCs?), others are disconnecting swaybar links (?). I'll figure it out.
Started this project yesterday, but quit when I looked up and realized from the jacking point I picked I had raised both back and front wheels off the ground. Back to Jacking A Car Safely 101.

 

[suprarx7nut]

Are H-N-L shifts typically a smooth lift, or is some small shudder to be expected? Never been in another LX to compare.

Mine occasionally has a thud or two. Nothing that feels alarming, but you can hear and feel a movement. Other times, it's perfectly subtle and fluid and my wife can't tell it's moving at all.

Got the springs. I'll be putting them in shortly. I'm seeing mixed approaches on videos - some look like they're able to replace very quickly (maybe this is only on LCs?), others are disconnecting swaybar links (?). I'll figure it out.
Started this project yesterday, but quit when I looked up and realized from the jacking point I picked I had raised both back and front wheels off the ground. Back to Jacking A Car Safely 101.

Check out my recent video. I show the rear spring removal and replacement about half way through. You can see exactly what approach I used for jacking/supporting in the time-lapse and then I stop to show what brackets I removed. There may be some I didn't note well on video - just take your time and lower the axle very slowly as you watch for anything getting taught.

 

[OregonB]

Mine occasionally has a thud or two. Nothing that feels alarming, but you can hear and feel a movement. Other times, it's perfectly subtle and fluid and my wife can't tell it's moving at all.



Check out my recent video. I show the rear spring removal and replacement about half way through. You can see exactly what approach I used for jacking/supporting in the time-lapse and then I stop to show what brackets I removed. There may be some I didn't note well on video - just take your time and lower the axle very slowly as you watch for anything getting taught.

This is fantastic. I hadn't found this vid. Thanks!

 

[OregonB]

Clean vehicle, very nice LX

 

[OregonB]

so everything worked, kind of, putting new springs in. I failed to keep an eye on the brake lines, we'll see if that cost me. So I am hung up on this problem: the sway bar connection on the drivers side is not lining up anymore & short of using a bottle jack to force it in, I'm stumped. Tried various jack heights, nothing works. I even tried loosening up the pair of tie rod brackets, to get so wiggle, that was a non-starter. Although now I know the torque is 13 ft/lbs on those. Should I try moving the jack over to left of center on the axle? Or just loosen the tie rod post down to meet? Or should I have waited until after this to tighten the lower shock bolt (72 ft/lbs I believe).
...limited knowledge to apply. So close to finishing job...so far!

 

[ramangain]

Ah, wish i had seen this sooner to advise. Sway bar brackets up top are what you remove bolts from, not that bottom troublesome one.

Undo from top, redo that bastardly single bolt, then reattach up top

 

[OregonB]

I'm learning a ton, thanks. Hopefully no expensive mistakes.
This threaded bolt is the one I should loosen up to mate up and re-tighten? (can't find any torques specs for this assy)

 

[ramangain]

No no. It's the top half of the sway bar bracket. Should be a 12mm IIRC. One near the top of the tire in the wheel well, one underneath bolted "upwards" into the rig.

 

[MJK]

FWIW, I've found the most consistent way to to get AHC reading on my truck is to park on level ground with the engine running, go to Low, wait, go back to N, and take your reading once the accumulator pressures stabilize (at around 10.3 on my truck).

No clunks here, but the front did go down faster/up slower than the rear before I tightened Tbars.

 

[ramangain]

This guy and his companion on the underside. Maybe it's a 14mm, I don't quite remember.

 

[OregonB]

Made it work, thanks for the tip. Now that I know what to do, it's a 90 min job - not 3 hours! Just happy to see no hydralic fluid leaks - yet - so hopefully did not strain the brake lines!

As predicted from the threads in Mud, the results were 1) AHC not going into Low now (front end does, but rear does not) and 2) bit of a springier ride when not loaded up. Not predicted (or I didn't see coming): those new springs brought CL of rear wheels to edge of well now 22-1/2" in neutral - this is now 2" above OEM 20.5"!!!

New pressures: the #'s were a bit scattered... in 6 measurements the average at fronts now is 6.4 vs. 7.1 or so before. At the rears the avg is now 7.0 vs. 9.0 range (!) before new springs.

Am studying the "ABCs of AHC" items closely. And hanging on to my old springs...

 

[LXKevin]

You ordered and received those King Springs really fast.

 

[OregonB]

I gave up on the Kings, called Slee and threw in a pair of used stock LC springs.

 

[OregonB]

I had an LC before this current rig, so the stiffer bounce from the rear is not unfamiliar. I'll miss that LX suspension smoothness, but I won't miss it trying to shift into Low every time I hook up my trailer or struggling to get into High, which I actually use (unlike Low which I almost forgot I even have) driving on rougher terrain. And it is 2" higher in the rear now in Neutral, which took some getting used to. I'm not sure if my rear pressures are reading accurately (0 on multiple reads) as the springs have taken over & it also no longer shifts into Low... might just leave the AHC sensors untouched and call it good enough. And maybe when the Kings become easily available I'll try those.

 

[LXKevin]

Ah i see
I went with 30mm spacers to my stock springs. Working great although i have not towed with it yet.