2" Drop shackles for 2015 2500HD?

Cowpie · September 9, 2015

Ha, Ha! Thought that might trigger a comment. Those are Air Tabs. I have used them on my semi trucks for years to improve air flow at rear of vehicle and between tractor and trailer. I thought I might give them a try on the 2500. I have them on the back, as you mentioned, and also all along the rear of the cab. You can see them up there in the photo. Time will tell if they really do any appreciable good. I do notice a little less dirt buildup on the back when I run up and down my gravel roads, so they must be doing something. I like to think they might help with mpg, but who knows. Just a test on my part. They have done well on the semi, and I had a few of them left over from the last semi application, so I gave them a new home.

Cowpie · September 9, 2015

Might have forgot to mention on tire pressures, I usually run 50-55 PSI in the tires when empty and light loaded. Sure, the TPMS has a cow, but I just dismiss it on the DIC and ignore the light. The ride and handling are significantly better. Especially in loose gravel, mud, and such. No negative effect at highway speeds, and no increase in tire wear. MPG is a little better, which flies in the face of all we have supposed over the years. I attribute that to less wheel hop, especially in the back, and the anti-slip feature constantly micro braking to compensate. I have no scientific data to back that up, just conjecture. Of course, if one is going to be loading up the pickup significantly or towing heavy, by all means, air them back up. Experiment and see what works best for you.

ickyoldman · February 27, 2017

I run 50 psi on mine also when not loaded.....It's brutal when fully aired up with no load.

powerhaulic · November 3, 2017

Seriously considering the shackles here as well.

Tire aired down to 60 no light on dash

Just got to Fla towing our 9000# travel trailer, even with that weight the rear was high so 2" drop should be about perfect

SMiller · November 4, 2017

Just remember that drop shackles require cutting the bed seam, some people are not ok with cutting sheet metal for install.

Myself I would raise the bed to avoid the cut but some don't mind the cut, if I lived in the salt belt and planned to keep my truck I would not be ok with it.

Agree with everyone else the rear of the truck is ridiculously high.

Cowpie · November 7, 2017

Well, I live in the "salt belt" and I had not problem with it. But then, the couple of miles of gravel roads I have to run every time the truck leaves the driveway probably take more of a toll on it than the cut. Besides, if the box does go south, then I will have ample excuse to put on a bed from Alum-Line. Just from what I have seen over the many years with many trucks is that fender wells succumb to body cancer far quicker than anything else. And that has nothing to do with a seam cut. Did the McGaughy's drop almost 3 years ago and no indication of it being a problem.

As a side note, I installed some Sumo Springs in the back end for a little extra support with the lowered back end when loaded up heavy. Doesn't affect empty ride at all but is real nice with some heavy weight in the back end. I just went with the simple set that replace the bump stops on the truck. The provide 1500 lb support. With the lowered back, the Sumo's ride on the axle all the time, even empty. Almost like having air ride support when loaded up.

https://www.supersprings.com/shop/ssr-207-47/#comment-5286