Picked up my brand new SunnyBrook 31BWKS fifth wheel on Friday. The dealer installed a new Reese 18K Signature Series slider hitch, which I was very pleased with (VERY sturdy looking, single jaw/hook locking mechanism, no noticable slop at all when stopping/going, easily/completely removable).

Well, after hitching it up, I started off on my maiden fifth wheel tow. Duramax handled it well, but doesn't whip it around like the previous TT we had. Handling seemed superb, and no sway or porpoising whatsoever. But what I did notice was (for lack of a better term)... "chugging". This was NOT the rollercoaster "porpoising" or the side to side "swaying", but a series of backward/forward jerks, like what happens when your car is running out of gas and trying to suck up the last few drops, lunging forward. Or, similar to the effect of the antilock breaks kicking in. It wasn't that severe, but certainly noticable, perhaps at a frequency of about 3 little "chugs" per second, at random intervals.

I know there is no problem with the truck. Pressure was set to 80PSI on all the tires just before I left, and air bags set to 30PSI which levelled it out nicely. The drive home was up I-39 from around the Bloomington, IL up to around Peru, IL which is pretty much a pancake flat interstate across the plains, with normal bumpyness for an interstate. My speed was between 60-70 MPH, usually around 63 MPH. Once I got off the interstate, I had 15 minutes on Hwy 71, varying speed between 55MPH and 30MPH, and the chugging seemed to dimish somewhat. I did notice that WHENEVER I let my foot off the pedal I would ALWAYS get three "chugs" and then the chugging would stop. And, when putting the foot back on the pedal I would typically get some chugging again.

I'll be taking the 5er to have it weighed today... plan to do some more testing as I drive it there/back. I think there is PLENTY of pin weight, but I'll know for sure after I weight it.

Any ideas on what's causing this? A forgotten adjustment on the hitch? Thanks in advance... --Paul.

The first thing I'd check is how level the 5er is when hooked up. If you are running either nose up or nose down, you may see any number of symptoms that give a feeling of some instability. If this is the problem, then it should be a relatively easy matter to make adjustments with your hitch and/or pinbox. Good Luck!

If it feels like a stick shift left in high gear at too low a speed then I had the same problem. Dealer changed a fuel pump in the valley of the motor to correct it.

I'm suspicious of your brake controller. :confused: Since you just picked the 5ver up I assume this is a dry weight tow so the pin should be within specs. It almost sounds like the brakes are kicking in/out, especially when you mentioned that it happens when you accelerate and decelerate. The Prodigy, like most brake controllers, has an algorithum in them for inclines and declines to adjust braking power accordingly. You may have a faulty brake controller or a short somewhere. :o:

With your 5ver hooked up what does the brake controller read? It should show "C" when connected. Did you adjust the brakes after they warmed up? If the 5ver sat a while it is possible the brakes may not be fully engaging/disengaging and need maintenance/adjustment. If the brakes aren't fully retracting they'll drag, heat up, then release. The momentum when this happens goes to the pin and the tow vehicle. The RV dealership should have covered that during PDI. ;)

You likely will have some warranty issues, adjustments and so on that need to be done to your 5ver. This is something they should fix, that is unless they didn't install the Prodigy. I have a Sunnybrook 5ver and am very happy with it. Good luck! JJ :)

I must agree with the other guys, brakes (possibly your controller can't handle that many brakes depending on what you controller is. Some only do 2 wheels well while others do 4-6 well), and I just switched from a Dually to 3/4 and have asked what to do for the ride, but I haven't noticed what you are, I just notice a bone jarring bump so I am adding airbags. I did have to adjust the hitch to get about 6-8inches above the bed rail which leveled out the ride.

Hope you figure it out, let us know.
J

Do you have a airride hitch on on the 5er?

I had something similar. It was cured by moving my hitch center 2" forward of the rear axle centerline (my hitch is adjustable fore-and-aft). Also if you have an articulated hitch, like air ride hitches are, and the pivot point is not at the same horizontal level with the pin, that can cause it.

PaulRahoi , what have you found?

Same hitch, same problem pulling 38' Montana Big Sky. Installed TrailAir Pinbox and Centerpoint suspension. Pretty much corrected all of it.

Sorry on the late reply...

Bluenote: It was near perfectly level... not the problem...
RickDLance: Don't think it's the fuel pump...
JJ: Not the controller... controller is fine...
Rightstuff... My hitch is not adjustable, and don't think location is problem...

I took the SunnyBrook to get it weighed, and drove on a different interstate (I-80), and experienced amost no CHUGGING-- except a little when I let off the peddle. I was going just as fast, if not faster, so I was thinking: "Was it just that stretch of I-39 that was causing the problem???" Several days later, I noticed that my fresh tank was FULL, and blank/grey were 2/3 full...!?! I would never have thought on a NEW 5er, but maybe they were doing some testing at the dealership and forgot to drain them. On my previous TT, having the tanks full would cause serious sloshing, which in turn caused some sway-- perhaps in this case (with larger tanks) it was causing the CHUGGING? I still don't know for sure, but want to test it out again with the tanks EMPTY on I-39 when I get a chance (very busy lately)...

Paul.