We picked up the trailer today and drove around a bit with the suspension on the truck configured as it comes from the factory. The trailer rode well on flat, smooth surfaces but would pulse violently on expansion joints or other sudden bumps. Once we got it home, I started trying to diagnose the issue and found an obvious culprit.
The lower overload was barely making contact, and would be momentarily engaged when when hitting a bump but otherwise not utilized. A conventional lower overload configuration consists of a thick, flat spring called an overload leaf, and a spring pack above it that will only make contact with the overload leaf when there is sufficient weight on it to flatten it out. It looks like this, minus the silver aftermarket components that are attached to the overload leaf.
There is a company called TorkLift, who makes a product called StableLoad, to take up the slack between the spring pack and the lower overload. More on that later.
For some reason, Ram uses a non-conventional design for the lower overload on my truck. TorkLift, and other vendors who provide similar items, do not have products out for it yet. A universal StableLoad won’t fit the profile or meaningfully fill the gap between the springs, so that is out. I called them and it doesn’t even sound like they’ve looked at one of these trucks yet.
One thing about filling the gap is that if you fill it to the point where the lower overload is engaged when the truck is empty, it will make for an extremely uncomfortable or possibly even dangerous ride; this would basically be the same as having no suspension on the rear of the truck at all.
After mulling over it a bit, I ran to the local auto parts store trying to find some larger bump stops to replace the small rubber ones from the factory. I found some that I thought would work, but they were not tall enough at a little over 2″, and I don’t believe they were strong enough to hold up over time. I went back and picked up an inexpensive 2″ receiver and started cutting into it.
I ended up cutting out two 2x2x2″ brackets, and using them as spacers between the lower overload and the bump stop.
This results in enough space between the lower overload for it not to be engaged during empty riding – and quite a bit of testing confirms this – and full engagement with the weight of the fifth wheel on the truck.
With the lower overload fully engaged, the ride is substantially improved over the previous configuration. Being that the brackets are made from a receiver tube and secured with 304 stainless hardware, they should last a long time even under a lot of weight and abuse.
The truck has a 100lb toolbox and 60 gallons (over 400lbs) of fuel in it, and the trailer has a pin weight of at least 3000lbs (likely well over that). The fact that the lower overload on this truck is not fully engaged with over 3600lbs in the bed is a bit strange – if this isn’t a manufacturing flaw then it is a design flaw, at least with the target market for these trucks.