Attention: TDR Forum Junkies 
I'm not a novice at pulling 5th wheels, but I've run into a problem with the new truck that has me stumped! We pulled the same 5ver for many miles with our 1996 Ram 3500 dually and never experienced this problem! 
(Please note - both trucks were/are 4x2's. )
When braking on concrete pavement, as the truck speed drops below, say, 20 MPH, the truck/trailer sometimes goes into a violent "surging" - this actually gets worse as the speed drops. Something is apparently getting excited by the expansion joints in the concrete pavement to get this started and to "drive" it since I've never experienced the problem on asphalt pavement.
It doesn't seem to be related to the soft drivetrain mount surge you can sometimes get in 1st or reverse since when it happened yesterday, I had the clutch in and the engine at idle!
Although the "surge" feels like it's front-to-rear, I've never had any banging from the hitch, and I've even checked to see if there's any evidence of the B&W gooseneck receiver moving due to the loads being imposed by the companion 5th wheel hitch. The gooseneck receiver is a tight fit through the 4" hole drilled in the bed, and the seam between the receiver and the bed was filled with Line-X when the bedliner was sprayed in. If the receiver were moving back and forth, I'd expect to see the edges around the hole in the bed "rolled up", or at least the Line-X should be cracked between the bed and the receiver - neither is evident.
The only thing I can think of that might be a clue is that, on the Interstate, the 2002 has a "bouncing" tendency in the rear that our 1996 never had. It feels like the 2002's springs are stiffer, the factory shocks are softer and the truck is barely hitting the overload springs and then bouncing off them - the 1996 was a good 1" or more into the overloads pulling the same 5ver. Therefore, I'm about ready to order a set of Rancho 9000's for the rear to dampen down the bouncing, but I don't know if this will have any effect on the "surging" problem during braking or not.
What's different between the 1996 and the 2002 trucks, bearing in mind that they're pulling the same 5ver? 1. The brake controller - I doubt this is the problem since the surging only takes place on concrete, and I've never heard anyone else have this problem with the Jordan Ultima 2020. 2. The hitch - we had a conventional Reese 5th wheel hitch in the 1996; we have the B&W hidden gooseneck/companion 5th wheel in the 2002. If the hitch were moving back and forth, I'd expect to see or hear some evidence of it - it's not there. 3. The truck's rear suspension - the 2002 appears to have a stiffer main spring pack and softer overloads than the 1996. That's why I'm suspicious that the concrete expansion joints are exciting the rear of the truck, getting it bouncing and causing this problem.
What do you guys think? Has anyone seen and cured this before?
Rusty
(Please note - both trucks were/are 4x2's. )When braking on concrete pavement, as the truck speed drops below, say, 20 MPH, the truck/trailer sometimes goes into a violent "surging" - this actually gets worse as the speed drops. Something is apparently getting excited by the expansion joints in the concrete pavement to get this started and to "drive" it since I've never experienced the problem on asphalt pavement.
It doesn't seem to be related to the soft drivetrain mount surge you can sometimes get in 1st or reverse since when it happened yesterday, I had the clutch in and the engine at idle!
Although the "surge" feels like it's front-to-rear, I've never had any banging from the hitch, and I've even checked to see if there's any evidence of the B&W gooseneck receiver moving due to the loads being imposed by the companion 5th wheel hitch. The gooseneck receiver is a tight fit through the 4" hole drilled in the bed, and the seam between the receiver and the bed was filled with Line-X when the bedliner was sprayed in. If the receiver were moving back and forth, I'd expect to see the edges around the hole in the bed "rolled up", or at least the Line-X should be cracked between the bed and the receiver - neither is evident.
The only thing I can think of that might be a clue is that, on the Interstate, the 2002 has a "bouncing" tendency in the rear that our 1996 never had. It feels like the 2002's springs are stiffer, the factory shocks are softer and the truck is barely hitting the overload springs and then bouncing off them - the 1996 was a good 1" or more into the overloads pulling the same 5ver. Therefore, I'm about ready to order a set of Rancho 9000's for the rear to dampen down the bouncing, but I don't know if this will have any effect on the "surging" problem during braking or not.
What's different between the 1996 and the 2002 trucks, bearing in mind that they're pulling the same 5ver? 1. The brake controller - I doubt this is the problem since the surging only takes place on concrete, and I've never heard anyone else have this problem with the Jordan Ultima 2020. 2. The hitch - we had a conventional Reese 5th wheel hitch in the 1996; we have the B&W hidden gooseneck/companion 5th wheel in the 2002. If the hitch were moving back and forth, I'd expect to see or hear some evidence of it - it's not there. 3. The truck's rear suspension - the 2002 appears to have a stiffer main spring pack and softer overloads than the 1996. That's why I'm suspicious that the concrete expansion joints are exciting the rear of the truck, getting it bouncing and causing this problem.
What do you guys think? Has anyone seen and cured this before?
Rusty
I could easily see the situation you describe happening with the Tekonsha Sentinel inertial brake controller in our previous truck, but the Jordan Ultima 2020 is a proportional controller with a cable that runs to the brake pedal arm. Therefore, its output should be constant if I can hold my foot steady through the bucking that's going on when it decides to have a fit! 
