Quote Originally Posted by VX KAT View Post

To clarify what "Ala5ka" said in post #4...some people call the rubber part a "bump stop" and some call it a "spring helper".....Isuzu actually uses both terms in the part listing. I've attached a few pics of them. Some of us have cut the bump stop in half, allowing for about 4" MORE travel room before the rear axle hits the bump stop. It "improves" the slamming/jolt effect that you hear and feel from the rear axle going over rough roads. It is a only a little improvement, but I think it's worth it. You can always buy replacements from a junk yard or aftermarket ones if you want to go back.
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How do you get 4 more inches? Since the part is rubber abd it has open spaces in it I assume the stop doesn't really stop. I would think it slows by compressing and only stopping once the stop is compressed so that the open area dissappears. I would think cutting half off only gives you the extra equivilent to the size of the amount of rubber minus the open area.