Shackles and lifting

Just a thought for those with longer shackles. If you load the truck to the bump stops or even hit the bump stop empty, at that point isn't the long shackle pushing the rear of the leaf pack down too far, basically flattening the springs in a bad way? I'm no genius, just doesn't seem like a good idea to me. So please explain what I missed.

 

You would need to take apart the rear suspension and cycle it to know for sure. Having a leaf spring go flat is ok temporarily. Going into a negative arch will definitely lower the life span of the leaf spring. This is common practice when setting up a real offroad leaf suspension. Most lift kits don't take this into account which is why I'm not a fan of lift shackles unless the leaf pack has been designed around shackle.

 

That makes sense. In another thread there was a discussion on whether bumpstops should be upgraded with shackle lifts. What are your thoughts on upgrading bumpstops for modest 1” shackle lifts and what bumpstops would you recommend for that application?

 

I would use yellow Sumo springs and cut them off to a height equal to factory bump stop plus whatever the added shackle length is plus 1/2" for compression.

 

Thanks again. So instead of using a taller bump stop, with a 1” shackle lift I should cut the yellow Sumo Springs about 1.5” shorter than the stock height bump stop?

 

No! Cut them to a height equal to the factory bump stop height which is approx 2" or so plus the added shackle length or lift rating say 1.25" plus 1/2" for compression allowance would be 3 3/4" if your parts measure the same as my example

 

If you load up the truck with weight and it hits the Sumo springs it will ride much better than if it was sitting on the factory bump stop because you will have a progressive type bump stop with no hard impact.

 

Sorry, I’m a bit dense when it comes to rear bump stops, but thanks for the reply and for trying to help me understand! So with a shackle that provides a 1” lift, cut the Sumo springs so they’re about 1.5” to 1.75” taller than the stock bump stop?

I assume I should also get new U-bolts, too.

 

Spot on!

 

Gotcha! Thanks again! While searching Sumo Springs, I noticed they have blue (normal driving with occasional towing), black (bit more heavy duty) and yellow (heavy duty and for lots of towing). I don’t tow as much as I used to, but I occasionally haul a load. Is there a reason I should go with the yellow instead of the blue or black?