Sorry to hijack this thread. I think I just learned something new. I did not know that I need to keep the wheels off the ground when adjusting the torsion bar.......
I had turned the DS clockwise 4 turns about 10k miles ago and turned the PS clockwise 4 turns about 1k miles ago with the wheels on ground.
So did I cause any damage by doing that? And is there any remedy I can do?
If you have been using generous doses of thread penetrating oil before starting and if you were able to turn the torsion bar adjusters without too much drama, then it is less likely that any damage has been caused. Best to have a close look at the exposed bolt threads.
It helps to reduce the load on the torsion bars by raising the vehicle with wheels clear of the floor. This makes actually turning the adjusters easier.
This would be a good idea where the adjusters are very stiff, such as if a lot of rust or road grit is present, and/or there are concerns about ‘galling’ between parts (meaning metal is transferred from one part to the other in contact, as shown in the dramatic pics in this thread). In this case, suggest clean up visible parts of bolt threads as best possible with a wire brush to minimise rust, mud, road grit being dragged between the threads on the bolt and the nut, then be very liberal with thread penetrating oil – apply multiple doses several days before making torsion bar adjustments. Then start with multiple turns counter clockwise to ease the bolt – working with, not fighting against the torsion bar spring, aiming to ease the contact pressure between threads of bolt and nut and improve oil penetration, Then have another look at what thread you can see, use the wire brush again, more thread penetrating oil, then turn the bolt in opposite directions aiming to free the thread. Gently. Steady force rather than violent wrenching leverage which can cause or worsen 'galling'. Vibration can help -- by firmly striking the bolt head with a hammer. Sometimes flame heat may help, aiming to have the nut warmer than the bolt to increase thread gaps and relieve thread contact pressures -- see plenty of youtube videos on the general idea – in this case just be
very careful to avoid flame contact with wiring, fuel lines, brake lines, aircon lines, AHC lines and
especially AHC pressurised components.
Whatever, actual measurements of the
effect of the adjustments must be done with the wheels on the ground, preferably after a short drive around the block to settle the suspension.
Assuming that your LX470 still has a functioning AHC system, note that the torsion bar adjusters have only two purposes:
1. ‘cross-levelling’ the vehicle – measured with vehicle on a level surface (like a garage floor not in the street), wheels on the ground, without uneven side-to-side load distributions or weight additions in or on the vehicle – see attachment. [The point is to equalise the load carried by each torsion bar, to avoid different spring effects and different turning effects side-to-side,, and also eliminate any side-to-side ‘lean’],
2. adjusting the Front AHC pressure – done by
increasing the share of vehicle weight carried by the torsion bars by turning the torsion bars adjusters clockwise, thereby
reducing the share of vehicle weight carried by the AHC system and in that way
reducing the AHC pressures. The reverse is done in the less usual circumstance of the AHC pressures needing to be increased. [The point is that damping -- and therefore ride comfort -- is best when the AHC pressures are well within the FSM-specified ranges. The Toyota Electronic Modulated Suspension (TEMS) real time adaptive damping is controlled by the Damping Force Control Actuators (to which the ‘globes’ are attached}, in response to signals from the Suspension Electronic Control Unit (ECU). Damping is poor when AHC pressures are too high or too low or when 'globes' are in poor condition -- or when a fault condition (usually with a relevant DTC) causes the ECU to prohibit operation of the AHC and TEMS systems and places them into 'fail safe mode'].
Different to a conventional suspension, the torsion bar adjusters cannot be used to adjust the vehicle ‘ride height’ on a functioning AHC suspension – this can be done only by using the Height Control Sensor adjusters to set the ‘ride height’ at “N” height setting.