Question about LCA jounce/bump stops

Crafty_z28 · Apr 13, 2026

Hey everyone, just wondering if somebody may actually know the answer to this. What is the actual difference (other than visually) between the regular 4x4 1500 bump and the Z71?

The regular non z71 for a 1500 4x4

The Z71 1500 4x4

I’m asking this because mine are due for a change and I figured while I’m rebuilding the front end I should change these out too, but before I order, for a truck that sees rough forest service roads fairly often would the Z71 bumps actually be an upgrade?

Thanks!

Marky Dissod · Apr 13, 2026

No idea what 'FSR' stands for?
Jounce bumpers are meant to be in contact with the suspension through most of the compression arc,
in our case when the suspension is compressed enough to be considered 'loaded'.
My GUESS is the Z71 jounce bumpers would be somewhat stiffer than the non-Z71, but not as stiff as the 2500/3500 jounce bumpers.
GUESSING because there is a blatant lack of GMT800 spring rate info, as in, how many lb-per-inch / Newtons-per-MilliMeter.
(I want to see if it's possible to use BOTH Z71 AND 2500/3500 jounce bumpers ...)

Crafty_z28 · Apr 13, 2026

Marky Dissod said:
No idea what 'FSR' stands for?
Jounce bumpers are meant to be in contact with the suspension through most of the compression arc,
in our case when the suspension is compressed enough to be considered 'loaded'.
My GUESS is the Z71 jounce bumpers would be somewhat stiffer than the non-Z71, but not as stiff as the 2500/3500 jounce bumpers.
GUESSING because there is a blatant lack of GMT800 spring rate info, as in, how many lb-per-inch / Newtons-per-MilliMeter.
(I want to see if it's possible to use BOTH Z71 AND 2500/3500 jounce bumpers ...)

Forest service roads

Honestly I was thinking the same thing, just a stiffer rate. My issue is the cost difference to get them in Canada, would they be noticeable enough to be worth it.

I also saw somewhere mentioned the 2500’s will fit? Need to find more info on that one.