How-To Adjust BP-51 Preload

5th October, 2020

The BP-51 range of high-performance, bypass coilovers and shock absorbers is the result of an exhaustive development process aimed at delivering the ultimate experience in both comfort and control. Designed, developed, and tested entirely in-house by ARB’s team of Old Man Emu ride control engineers, BP-51 coilovers and shock absorbers are vehicle-specific and utilize existing mounting locations to provide easy installation without the need for additional vehicle modification. BP-51 coilovers provide preload, rebound, and compression adjustment which offers class-leading ride customization that can be tailored to an individual vehicle or trip requirements.

If your vehicle is outfitted with accessories that add constant weight such as a bumper and/or winch, the additional weight from those components will have an effect on the ride and handling characteristics of the vehicle resulting in the need for suspension with increased spring rates. The BP-51 coilovers alleviate the need to replace coil springs when adding constant weight to your vehicle due to the adjustable preload capabilities. 

BP-51 preload can be defined as the amount of spring compression at full extension. Preload compresses the spring which in return creates a force that translates to the vehicles chassis. This additional force (preload) can be adjusted to compensate for additional accessories that add weight, such as a front bumper and/or winch.

When adjusting preload on the BP-51 coilovers, we recommend using a wall mounted spring compressor and OME spring seat tool #VM80020001 to aid spring adjustment. Here are instructions that will show you how to adjust preload on your BP-51 coilovers. It is highly recommended a professional suspension shop assist with these steps. 


It is highly recommend a professional suspension shop assist with these steps.

There is a misconception that more preload will add additional ride height to your vehicle. While in theory this may be the case, the BP-51 coilovers are not designed this way. Adding additional preload to gain ride height will result in harsher ride quality and it will also limit the amount of travel in your front suspension. Preload should only be adjusted to compensate for additional constant weight from aftermarket accessories.

The preload, rebound, and compression adjustability sets the BP-51’s apart from its competitors. Extensive dyno, real world and destructive testing has been undertaken during the development process to ensure that reliability, longevity and performance all meet ARB’s impeccable standards.



Vehicle No Accessories ARB Bumper ARB Bumper & Winch
Tacoma 10mm 15mm 20mm
4Runner 10mm 15mm 20mm
Land Cruiser 200 10mm 15mm 20mm
FJ Cruiser 10mm 15mm 20mm

To learn more about BP-51 Suspension Systems click here.