Sway Control - Who Saved the Day?

4bamayoungs wrote:


We are set up at an RV park down at the beach this weekend but I may hit the scales on the way home Sunday and take you up on a more detailed workup.

I didn’t get too much into the cause of the incident earlier because it wasn’t the point of the post, but for the benefit of those interested, the replies here are spot on. Not enough tongue weight.

At the time I was unaware of the location of the fresh tank and didn’t realize what I was doing to weight distribution when I filled it up.

Additionally, I had recently had a receiver hitch welded into the frame on the back for a bike carrier. We had four bicycles hanging on it, and I didn’t think it would make that much of a difference. With hindsight, four adult bicycles hanging 18’ or so behind the center of the axles would exhibit a TON of leverage.

After the “event”, I pulled over into the breakdown lane and drained 3/4 of the water out and put two of the bikes in the living area. That eliminated the white knuckles for the rest of that leg and the next morning I made more adjustments prior to starting the second leg. The rest of the trip was uneventful.

If you are going to the scales and want to know loaded tongue weight you will need 2 different sets of scale weight the day you are weighing the rig. Ideally you can get all 3.

1. TT and truck hitched and WD bars tensioned. (means WD is engaged) Truck front axle on 1st first, truck rear axle on 2nd scale, TT axles on 3rd scale. Take a weight.

2. Don't move the truck, get out and unchain the WD bars. (means no WD engage) Truck front axle on 1st first, truck rear axle on 2nd scale, TT axles on 3rd scale. Take a weight.

3. Go unhook the trailer, weigh just the front and rear truck axle. You have to do this the same day to get a true weight to subtract from weight 2 to get a good TW.

Items 2 and 3 are needed to get a true tongue weight and trailer GVW. Item 1 lets you now how the truck axles are when WD is engaged.

Tell the person inside the scale room you need to get 3 sets of weights and you need to adjust the loads between weights. Most times load adjustments when you never leave the yard are at a reduced charge rate. Find out how to talk to them over the intercom at the scale.

If you can add to the list, getting the dimensions from the center of the rear axle to the center of the bike rack in the back and give me a weight estimate of the 4 bikes and the rack, I can tell you how much that unloaded the TW. The other questions I asked would be how much the fresh water tank full and 3/4 emptied unloaded the TW.

Yes, low TW was part of your problem. However unless you check all the other variables you never know how close to the edge of being stable you are. You can learn from this event about how far down the tongue weight went to aggravate up a problem by the numbers. And if you understand the other variables, you can see how close to the edge or not they are.

Your post sparked my interest as I thought I could help as I had a stability event on my 2500 Suburban on a 26 ft TT and TW had nothing to do with it as the TW was 20% then. The trucks characteristics itself had changed due to putting new tires on. When we bought the camper in my sig, now 32 feet, I knew how close that combo was to being stable and its limits. In my specific case, that was why I traded it to the F350 using the Burb for only a short while. I'm not saying your rig is in the same place mine was, but you will never know unless you run the numbers.

Have a good trip at the beach and if you want to pick this back up, let me know. PM me if you want to do it offline.

Hope this helps

John