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Rubicon spring rates measured

fixbroke

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This information might be useful for anyone looking at DIY suspension changes. These springs are from my JTR with plastic front bumper and manual transmission.

corner / part number / spring rate@measurement load
FR 68341340AC 130 lb/in @ 800 lb
FL 68341339AC 139 lb/in @ 765 lb
RR 68341450AB 170 lb/in @ 1000 lb
RL 68341449AC 182 lb/in @ 1000 lb

I ran out of stroke on my press and couldn't get as high as I wanted for load values, so take these with a grain of salt. I also found both front and rear to be variable rate, so these numbers are only meaningful at the tested load. Each corner of my truck has a little over 1000 lbs acting on the spring, according to my calculations. Using a little Excel trickery to forecast the front spring rates at 1000 lb creates the following:

FR 134 lb/in
FL 141 lb/in

Here's the graphical data. Note that I was measuring to the nearest 1/8" for the first few measurements on the rear springs, which is why those lines are so jagged.

upload_2020-4-1_16-16-45.png
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fixbroke

fixbroke

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Yeah, some good info there too. I used my measurements plus the figures in those threads to get an ideal-ish front rate of 149 and rear 187. The stock front spring rate is way too soft once a steel bumper and winch are added, especially if your Jeep came from the factory with a plastic front bumper. It seems that the steel-bumper Jeeps get a higher front rate spring than their plastic-bumper counterparts.
 

RushJeep20

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This information might be useful for anyone looking at DIY suspension changes. These springs are from my JTR with plastic front bumper and manual transmission.

corner / part number / spring rate@measurement load
FR 68341340AC 130 lb/in @ 800 lb
FL 68341339AC 139 lb/in @ 765 lb
RR 68341450AB 170 lb/in @ 1000 lb
RL 68341449AC 182 lb/in @ 1000 lb

I ran out of stroke on my press and couldn't get as high as I wanted for load values, so take these with a grain of salt. I also found both front and rear to be variable rate, so these numbers are only meaningful at the tested load. Each corner of my truck has a little over 1000 lbs acting on the spring, according to my calculations. Using a little Excel trickery to forecast the front spring rates at 1000 lb creates the following:

FR 134 lb/in
FL 141 lb/in

Here's the graphical data. Note that I was measuring to the nearest 1/8" for the first few measurements on the rear springs, which is why those lines are so jagged.

Jeep Gladiator Rubicon spring rates measured upload_2020-4-1_16-16-45

is FR and FR (driver or passanger)?
 
 



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