ABS for your FJ40- Asymmetrical Bump Stop Extenders
Few Landcruisers I see in my shop or on the Net are still in completely stock trim. Even amongst the resto crowd, modest lifts are common. And the wheeling crowd usually sports several inches of lift on their rigs.
Of course, right after the lift comes the larger tires that the lift helped accommodate in the first place. But what about sheetmetal clearance? Once the larger tires are installed, the likelihood is that they will contact sheetmetal long before the axle hits the factory bump stops.
In my opinion, extended bump stops are one of the most under-considered aspects of a lifted Landcruiser. In many instances, Landcruiser owners do not even consider extending their bump stops until they experience either a shock failure [from collapsed stress] or sheetmetal damage. Further, in the vast majority of cases, the extensions that are offered on the market are sub-optimal in that they are designed to mimic the truck‘s original suspension geometry, which does not line up properly with the lifted vehicle. If you think about it logically, you can see why it would not.
When add lift to a leaf sprung vehicle, the frame end of the spring remains anchored in the original location. Therefore, a spring lift can be described as increasing a pie wedged shape between the axle’s old and new locations relative to the frame directly above it, with the frame end of the spring at the apex of the wedge.
Further, when the axle moves upwards towards the frame, it does not move directly up and down, but in an arc, again with the frame end of the leaf spring as the anchor point. Therefore, the point at which you will want the axle to contact the bump stop is not likely to be directly below its original location, but somewhere out on an arc that is closer to the frame end of the leaf spring. Enter the ABS.
I designed the asymmetrical bump stop extenders to help move the factory stops into an orientation more likely to make an ‘even’ contact with the axle than ones lowered directly down from the stock location, which becomes more critical as lift and tire size increase. I am currently offering the ABS in three nominal sizes, with increasing tapers appropriate to their lengths: 1.5”, 2.5” and 3.5”.
Few Landcruisers I see in my shop or on the Net are still in completely stock trim. Even amongst the resto crowd, modest lifts are common. And the wheeling crowd usually sports several inches of lift on their rigs.
Of course, right after the lift comes the larger tires that the lift helped accommodate in the first place. But what about sheetmetal clearance? Once the larger tires are installed, the likelihood is that they will contact sheetmetal long before the axle hits the factory bump stops.
In my opinion, extended bump stops are one of the most under-considered aspects of a lifted Landcruiser. In many instances, Landcruiser owners do not even consider extending their bump stops until they experience either a shock failure [from collapsed stress] or sheetmetal damage. Further, in the vast majority of cases, the extensions that are offered on the market are sub-optimal in that they are designed to mimic the truck‘s original suspension geometry, which does not line up properly with the lifted vehicle. If you think about it logically, you can see why it would not.
When add lift to a leaf sprung vehicle, the frame end of the spring remains anchored in the original location. Therefore, a spring lift can be described as increasing a pie wedged shape between the axle’s old and new locations relative to the frame directly above it, with the frame end of the spring at the apex of the wedge.
Further, when the axle moves upwards towards the frame, it does not move directly up and down, but in an arc, again with the frame end of the leaf spring as the anchor point. Therefore, the point at which you will want the axle to contact the bump stop is not likely to be directly below its original location, but somewhere out on an arc that is closer to the frame end of the leaf spring. Enter the ABS.
I designed the asymmetrical bump stop extenders to help move the factory stops into an orientation more likely to make an ‘even’ contact with the axle than ones lowered directly down from the stock location, which becomes more critical as lift and tire size increase. I am currently offering the ABS in three nominal sizes, with increasing tapers appropriate to their lengths: 1.5”, 2.5” and 3.5”.
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