lx470 Suspension feels loose (1 Viewer)

[Castamile]

This forum has been extremely helpful, I learned everything I know about Landcruiser from here. so thank you to everybody who contributes to this forum!!!

I have a unique situation, I currently have two 2001 LX470, yes two identical ones, one with 174,xxx miles and one with 170,xxx miles. The one with slightly fewer miles feels considerably "loose" or less tight than the other one. Especially when braking at low speed it rocks slightly back and forth after the car stops while the other one feels just solid.

I have the luxury of swapping globes and rear springs but that made no difference in either car. I changed the brakes and cv axle on the "loose" one but that didn't affect anything either. The globes check returned 14 points on the reservoir, no AHC code in techstream. AHC pressure test is front 6.9 and 7.3 on the back which I know is a bit high and I need to address that but it's the same in both cars so I don't think it's the reason for the rocking/bouncing.

it's probably worth mentioning that the driver side was lower than the passenger side. I adjusted the torsion bars and got the two sides level. however, the driver side torsion bar bolt is screwed in all the way while the other one has about an inch to go still.


I'm lost at this point as I don't know what else to check/swap.. what else could it be?

 

[geanes]

Spring rates have likely worn out i.e. tb and coils no longer support the way they should. Probably need to re-index the TBs to get more adjustment and get back some spring rate. I'd bet your coils and tbs are like mine were....worn out.

 

[BullElk]

Bad shocks??? That may not be correct but someone here will know for sure.

 

[nukegoat]

Control arm bushings

 

[nukegoat]

Spring rates have likely worn out i.e. tb and coils no longer support the way they should. Probably need to re-index the TBs to get more adjustment and get back some spring rate. I'd bet your coils and tbs are like mine were....worn out.

He said he swapped springs

 

[geanes]

He said he swapped springs

Didn't catch that. That being the case, now I'm wondering if the Sport/Comfort switch is actually working. It might be stuck in Comfort (regardless of switch position) which could cause the Cadillac-like squishy ride (squat/dive, etc.).

 

[lowenbrau]

I think I understand what the OP means. I don't find my LX to be too 'loose' but if you are at a red light and let the rig roll a foot forward and then jab the brakes its like a bathtub full of water sloshing back and forth for a second. Just seems like everything rubber has gone soft. I've swapped out everything that is obviously worn out and even put new factory bushings in the adjustable shocks which still function like new.

 

[trdcorolla]

I sort of have the same feeling as @Castamile. I refurb'd my AHC (new globes, new rear springs, 30mm trim packer, flushed AHC fluid, adjusted TB's, refurb'd the f/r sway bars. My pogo stick ride went to the magic carpet ride everyone talked about. But, I think the LX could handle a litter better during accelerating/braking. I'm comparing it to my old lifted 4th Gen 4Runner with a stage 2 Icon setup and my lowered dd with lowering prings/struts/tower brace/rear sway bar. I haven't touched the control arm bushings. How much does it cost to replace those in the front? I can make the excuse to upgrade the rear upper/lower to get new bushings in that location, haha.

 

[Castamile]

I think I understand what the OP means. I don't find my LX to be too 'loose' but if you are at a red light and let the rig roll a foot forward and then jab the brakes its like a bathtub full of water sloshing back and forth for a second. Just seems like everything rubber has gone soft. I've swapped out everything that is obviously worn out and even put new factory bushings in the adjustable shocks which still function like new.

- that is a very good description of how it feels, like small water waves after the car stops. Did that fix your problem? Just bushings?

Bad shocks??? That may not be correct but someone here will know for sure.

- rear shock is seeping a bit but not leaking too much. the car remains height with no issues there. my understanding is that the shocks are nothing more than hydraulic lifts and the dampening actually happens at the globes.
is that accurate?

Didn't catch that. That being the case, now I'm wondering if the Sport/Comfort switch is actually working. It might be stuck in Comfort (regardless of switch position) which could cause the Cadillac-like squishy ride (squat/dive, etc.).

- I don't really feel much of a difference between the different Sport/Comfort switch positions. I will check that closely again. what could that be, bad switch? or other AHC issue?

In my attempt to level the car I maxed out the driver side TB. the passenger side still has at least 1 inch left in the screw. is that normal? do I need to reindex the TBs?
I did, however, manage to level it and get the front neutral pressure to ~6.9.

 

[Castamile]

Control arm bushings

I don't really get any steering vibration, could it still be control arm bushings?

 

[nukegoat]

I don't really get any steering vibration, could it still be control arm bushings?

Yes

 

[MongooseGA]

I'm with @nukegoat on the bushings.

My '99 LX (RIP) rode great until I drove my mom's brand new Hyundai. Getting back into the LX felt like it was just all over the place and was doing no good job at insulating the ride. AHC fully functional and ultimately had the globes replaced as well.

Move to my current '05 LX. Same mileage, but all of the consumables under the truck are new. I'll be damned if a Hyundai is going to be tighter than my own truck.

 

[Castamile]

@PADDO - do you have any advice?

 

[PADDO]

Are you sure you’re getting 14 graduations for L to H? If so then you’ve basically got new globes but you haven’t mentioned that. Case recently where I guy thought he was getting 10 grads and on rechecking it was actually 5. That was his problem. Probably not in a logical order as I’m running out the door but: I guess I’d want to rule out air in the system, confirm number of graduations and validate pressures and vehicle heights, do the 16 step test, drive it locked into position 1 (softest) damping, drive it while monitoring the damper steps, verify the damper switch is working (SW1 and SW2) in Techstream AHC data list, resistance checks on the damper stepper motors, check bushings and torques on all key front end nuts/bolts.

 

[PabloCruise]

Have you changed the AHC fluid in either LX?

 

[Castamile]

Are you sure you’re getting 14 graduations for L to H? If so then you’ve basically got new globes but you haven’t mentioned that. Case recently where I guy thought he was getting 10 grads and on rechecking it was actually 5. That was his problem. Probably not in a logical order as I’m running out the door but: I guess I’d want to rule out air in the system, confirm number of graduations and validate pressures and vehicle heights, do the 16 step test, drive it locked into position 1 (softest) damping, drive it while monitoring the damper steps, verify the damper switch is working (SW1 and SW2) in Techstream AHC data list, resistance checks on the damper stepper motors, check bushings and torques on all key front end nuts/bolts.

You’re right, on a second look it’s more like 11-12 grads and not 14. So I would say the globes are good.

Pressure is 6.9 in the front and 7.6 in the rear, which is high. I am thinking of getting the airbags to get the pressure down. Is that a good option?
Just to clarify the pressure on the “good” lx470 is 7.3 front and 7.9 rear and it still feels much better

The 16 step test is very confusing to me. After I put the car in test mode I am just not clear on what is the pass/fail criteria

Could you please elaborate on Damper switch ready and resistance check on damper motors?

 

[Castamile]

Have you changed the AHC fluid in either LX?

I followed @PADDO method of replacing ahc fluid. That didn’t change anything. Didn’t make it worse or better.

 

[Castamile]

I noticed a small play in the steering rack bushing. Not sure if that can affect the issue. I will attempt to swap these tomorrow......

 

[Castamile]

I noticed a small play in the steering rack bushing. Not sure if that can affect the issue. I will attempt to swap these tomorrow......

I changed the steering rack bushings this weekend. that didn't affect the suspension at all.
I have been reading the behemoth and extremly valuable Definitive list of AHC maintenance items Definitive list of AHC maintenance items

I found this awesome table from @PADDO
Problem symptom table
Definitive list of AHC maintenance items #511
I would like to go down the rabbit hole but don't know how to check these for example:
1- check control valve assembly
2- check fluid clog in the fluid line and shock absorber
3- perform Input signal check
4- check the resistance of the damping force control actuator
5- check air leakage of the gas chamber
basically I would like to follow the paths outlined in the third column of that table. how do I get that?

 

[Castamile]

I changed the steering rack bushings this weekend. that didn't affect the suspension at all.
I have been reading the behemoth and extremely valuable Definitive list of AHC maintenance items Definitive list of AHC maintenance items

I found this awesome table from @PADDO
Problem symptom table
Definitive list of AHC maintenance items #511
I would like to go down the rabbit hole but don't know how to check these for example:
1- check control valve assembly
2- check fluid clog in the fluid line and shock absorber
3- perform Input signal check
4- check the resistance of the damping force control actuator
5- check air leakage of the gas chamber
basically, I would like to follow the paths outlined in the third column of that table. how do I get that?