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Shock measurement at full extension/compression

mjmull

NAXJA Forum User
Location
Lancaster, PA
Hello,
I just finished the installation of a Clayton 4.5 inch long arm kit on my 2000 XJ. I did not order any shocks yet. I would like to measure for the shocks at full extension/compression of the suspension. My question, whats the best way of doing this? Thanks for any in put.
 
In the front you can pull a coil out to cycle the suspension up to the bump stop using a floor jack while the Jeep is supported on jack stands under the unibody rail. Same thing for droop, just let the axle hang as far as it can (might need to have the Jeep supported pretty high). Good time to check for clearances, trim fenders, and make sure your brake lines are long enough.

I'll be watching to see if somebody has a good answer for the rear. Can't just take a spring out because then the axle will not be constrained to its path of travel. I've thought about disassembling the leaf pack and flexing the axle with just the main leaf.
 
Do you have a friend who has a forklift, or any business that has access to one? if so that is an easy way to test. Put forklift forks under front tire, lift it up till just before the rear tire lifts of the ground - measure, then put the forklift under the rear tire and lift and measure. - of course measure both the compressed and extended sides.
 
Hello, thanks for replies. I lifted rear passenger tire until driver rear just came off ground and it was teetering between diver rear and passenger front. I took measurements as full extended on diver and compressed on passenger. Noticed my OEM shackles where hitting uni-body in rear. I ordered some extended boomerang shackles to install in rear, hopeful to correct that and get full flex from leafs. In front, I lifted uni-body until coils started to unload, took that as full extension. For compression in front, I did the math.

Front 26.75/16.5, Rear 24.75 14.25

Using JKS, bar pin eliminators and stem eliminators, Ordered shocks Fox 2.0 IFP, didn't need the measurements anyway with the range of 2.0s offered by Fox for the XJ. They are here, Saturdays project and lineament rack next week.
 
That's a long shock up front hopefully left yourself half inch of wiggle room. I'm running fox 2.5 inch lift jk shocks up front with tabs welded on lower control arm mount and they are 16.6 collapsed 27.2 extended with 5in of bump if I remember right
 
Best way is to disconnect the existing shocks (do not need to remove entirely, just unbolt the bottoms), then see how much travel you have in just the springs. Best to use a ramp or the like, but you can also use a hi-lift jack to raise a corner until the tire comes off the ground. Max compression and max extension will tell you the minimum shock travel, add an inch to both values to allow for movement under speed / force.
 
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