Michael Hayes talks about the advantages of fitting drop boxes to your 4x4 set-up.
Best Bolt-on Suspension Lift Modifications
One of the best bolt-on suspension lift modifications, the 'drop box' is a fabricated alternative rear mount for the radius arm. For castor correction in lifted radius arm-style vehicles, drop boxes can be used to correct the driveline angle by dropping the rear of the radius arms down to match the 'lifted' vehicle height, instead of rotating the front differential mounting point castor bushes do. This lowers the rear mount of the arms to counteract the same amount of lift, essentially returning the suspension to original-type geometry. The new mount position has to clear the original frame, and therefore in general the minimum lift height would be 3-4in and options up to and over 7in can be catered for.
The only drawbacks to this type of set-up are the reduction in ground clearance and the added chance of getting hung up on a badly designed drop box. A good design will allow full protection to the arm and bushes even when at full articulation, some so-called 'ultra-low profile drop boxes' actually fail to protect the vital suspension parts, all for the benefit of saving no more than a few extra millimetres of steel where it is needed the most.
In the right application, drop boxes greatly improve the driveability of the GQ and GU Nissan Patrol after a lift has been performed by returning the vehicle suspension specification closer to that of original, allowing the suspension to soak up the bumps and articulate off-road over obstacles. When choosing a drop box it is important to match the drop box sizing (amount of castor correction required) to the actual lift of the vehicle. Castor correction should be returned to approximate factory specifications with adjustment to compensate for any changes in tyre size.
A genuine 100% bolt-in low-profile drop box system to suit 3-7in lifts on a GQ or GU is the perfect option to help return your Patrol's suspension profile closer to original. The high-clear-clearance design, featuring asymmetrical tapered sides, hugs the chassis and provides clearance, protection and full articulation from your suspension, improving handling and performance both on and off-road.
Contact Superior EngineeringPhone: (07) 5433 1411
499 Uhlmann Road
Burpengary Queensland 4505
ASK THE EXPERTS: 4X4 Suspension Tech Talk With Superior Engineering