Lift truck up in air and measure total droop of rear suspension...measure from shock mount to shock mount

Then add an inch

That is extension

Now measure totally bottomend out...


Now look for a shock that is longer then first measurement but also is shorter then collasped

Example....my truck is 24 and 17....ride height is 18.5

My shocks are 16.5 and 24.5 for measurements

 

you only need enough down travel to get you down the highway/speed bumps without bottoming out.


a traction device like calvert traction bars uses the upward twist of your pinion on hard acceleration and re-directs that force to the top side of your leaf springs. a properly working caltrack system will shove the axle towards the ground which separates frame from the tire which is the "lift" that calvert mentioned.


skip to 1:20 on this video. notice how the shock extends when he launches instead of compressing. if you top your shock out, the suspension will not work.

 

another good example


this car could use a tighter extension setting, and possibly more tire pressure. it's hitting the tire way too hard but the traction bars and suspension are definitely working toghether. they just need to fine tune it.

 

any ideas on how to bottom it out? i have some sacks of cement i could load

 

im putting my gopro under my truck next time out, good idea

 

why do you want to bottom it out? measure your truck at ride height and find a shock with 4-5" of extension and as much compression as you can get.

 

In that case i ordered the correct shocks

 

Whats the measurements on the truck at ride height and the shock measurement?

 

truck at ride height: driverside 17 3/4" ,passenger side 18 1/4"

New Rancho RS999262 Extended Length: 23.830, Compressed Length: 15.280

It will give me 2.47" down room and 5.58 up room


A couple of questions to you guys:
-is a flip axle better then drop shackles for traccion? (being at 2/4 i have drop shackles and i like the drop right now, dont wana go 4/6)

-is it worth changing to poly leaf spring bushings?

 

I'd say run what you have and make a decision from there.