If you think your vehicle may be lopsided there are some checks that can be done to find out the cause.
Firstly, it is crucial that the vehicle is checked on a perfectly flat and level surface. Move the vehicle forward and backward a few time with the wheels straight to ensure the vehicle is not torqued to one side. The vehicle can then be assessed by measuring between the centre of the wheel hub to the bottom of the vehicle guard/flare. It is acceptable for a vehicle to have a difference of up to 12mm left to right (In fact it is common for vehicles like the Landcruiser 200 Series to have a variation of over 20mm from the factory.)
As Dobinsons Springs are manufactured to conform to the highest quality standards, and as all springs are 100% scragged it is extremely rare for Dobinsons springs to sag. Before removing the springs to check the free height there are a number of things that should be checked first;
Have the springs been fitted to the correct side?
See FAQ - Springs Marked Left Hand Side and Right Hand Side
Is there any additional load on the vehicle distributed evenly?
For example; is there a large toolbox/machinery/water tank/aftermarket fuel tank etc. fitted to one side of the vehicle?
Fuel Tank
One some vehicles such as Toyota Landcruisers and Nissan Patrols the fuel tanks are fitted on one side of the vehicle – it is a good idea to measure the vehicle with a full tank and an empty tank as this can also cause the vehicle to sit slightly lower on one side.
KDSS Sway Bar Systems
It is important to ensure correct fitment and re-setting of the KDSS system on vehicles such as the 200 Series Landcruiser as this can cause the vehicle to be pulled down on one side.
Damaged Shock Absorbers
A jammed or seized shock absorber can also cause a vehicle to sit un-level.
Damaged Sway Bar
Bent and damaged sway bars may also cause the vehicle to be pulled to one side.
Damaged Shock Absorber Bushings
On some independent coil over type suspension systems, worn or damaged bushes on one side may cause the vehicle to sit lopsided.
Damaged Control Arms
Bent or damaged control arms may also cause vehicles to sit unlevel.
Damaged Cab Mounts
Damaged or collapsed cab mounts can cause a vehicle to sit unlevel.
Damaged or Bent Diffs
Damaged or bent diffs, and in some cases on trucks diff or axles that have been bent during the wheel alignment process can cause the vehicle to sit lopsided.
Damaged Spring Seats/Coil Towers
It is quite common, especially on the rear of Nissan Patrols to have the spring seats bend upward at the top or crack due to overloading which will cause the vehicle to sit unlevel. It is also common on leaf spring Toyota Hilux’s that the lower spring perch bends away causing the vehicle to sit unlevel.
Bent Chassis
This is quite uncommon and improbable but it is possible that a bent chassis from vehicle misuse or overloading can occur and is generally difficult to diagnose and the springs should be checked first.