Originally Posted by Matt777
When I reach highway speeds my TT starts to "walk" or sway.
I'm fairly new at this so any information is appreciated.
Before you tow that trailer another mile I highly recommend that you stop and do a number of things and educate yourself before you get in an accident and cause damage and/or someone gets injured or worse. Please do not take the possibility of being overloaded and improperly set up lightly. If you are a new TT owner and have not been reading RV forums very long, there is a TON of real world info. that you will find that RV dealers and tow vehicle makers never tell you.
First, as suggested, read the thread entitled "Jack-knifed & totaled...advice". There is a lot of good info. there which will apply to your situation.
Secondly, go to a scale somewhere and weigh your tow vehicle and travel trailer and calculate the various weights. You will need 3 passes at the scale. One with tow vehicle (TV) by itself. One with the TV hooked up to the travel trailer (TT) and with the WDH hooked up. Then one with the TV and TT hooked up but with the WDH unhooked (put bars in back of TV). You can find the method of calculating the weights on this or other RV forums or just ask here. You want to find the actual total trailer weight, the actual tongue weight, the total TV weight and the actual TV payload capacity.
Dry weights published by an RV manufacturer mean nothing. Factory options are not included in the dry weight (UVW), anything installed by the dealer like propane tanks, batteries, spare tire, etc. are not included, anything you permanently install is not included (2nd television,eg.) and any cargo you put in the TT is not included. You should allow another 1,000 to 1,500 lbs for this which is the typical range that TT owners find. In some cases, even when you do not seem to load much cargo into your TT, you can find yourself near the max. GVWR figure. You *could* even overload your TT in some cases by just towing with a full tank of fresh water (like in our case).
We tow a very similar TT of 29'-1" overall with a UVW of 5237 lbs, dry tongue wt. of 518 lbs and GVWR of 6800 lbs. The factory lists the net (cargo) carrying capacity as 1563 lbs. However, the actual TT wt. is 6600 lbs leaving only 200 lbs for additional cargo and that's with only "normal" things in the TT for short duration camping. Another very important thing I found is that the actual tongue wt. is 960 lbs, which is approaching double the factory figure. We bought our WDH in advance of the TT delivery and initially bought 800 lb rated bars and had to upgrade to 1200 lb bars.
I assume that your TT model is a 26FK. The manufacturer's website says your TT dry weight is 4935 lbs, dry tongue wt. is 670 lbs and GVWR is 6495 lbs. Cargo carrying capacity is listed as 1261 lbs. You do not mention any options but you should know that every single option is not included in the UVW. Sometimes even things you would expect to be included are not such as the microwave.
You give no specifics on your TV so we will assume it is the shorter wheelbase SLE 2WD model. It was available with a "Heavy-Duty Trailering Package" but will use the base model info. Max tow capacity is 7900 lbs. GVWR is 7100 lbs. Max payload is 1774 lbs "when adequately equipped." Curb wt. is 5584 lbs. I could not find a figure for "GCWR" but I think from what I saw listed it is 11,000 lbs. This amount is what I found for the Yukon in the "Totalled" thread.
It is very important to know what the actual payload capacity of the TV is. Do not use the figure on the door jamb sticker or the published figure. The only way of getting an accurate figure is to subtract the scale TV weight from the GVWR figure. You could look at the payload capacity in terms of GVWR minus the curb weight giving 7100 - 5584 lbs = 1516 lbs. But this is an optimistic amount and only includes for a 150 lb driver and full tank of gas. If you include for passengers, pets and cargo, you can typically add in the order of 500 lbs to the TV which would reduce the available payload to about 1000 lbs. Curb weight will not include factory options or dealer or owner installed items so the 1000 lb figure can easily be less. I would say that at the absolute max. you have an actual payload capacity of 1,000 lbs but in actuality, much less than that, esp. if you load it with some heavy camping items like generator and firewood.
The GCWR figure (gross combined weight ratio) is very important to know. This is the maximum allowable weight of TV plus TT. The GCWR for this vehicle was not readily found on the internet which is NOT a good thing. GCWR is the max. TV and TT weight combined and in this case, 7100 + 6495 = 13,595 lbs. This is substantially in excess of the GCWR for this vehicle. Going up hills you will be over-stressing the drivetrain and on downhills and emergency stopping, you will be over-stressing the brakes. Being that far over the GCWR will create safety and handling problems. Not good at all on this aspect.
You are within the max. "towing capacity" amount. This is the max. amount for pulling in a horizontal direction. Payload capacity is the max. vertical load on the TV. You are about 1,000 lbs below the max. tow capacity limit so should be fine there.
I highly suspect that you will find your actual tongue weight to be near 1,000 lbs and possibly over that. You will thus be over your max. available payload amount. Not good, especially on a short wheelbase vehicle. For estimating, I would use the upper range of 15% of the TT GVWR - .15 x 6495 = 974 lbs.
You give no specs on the hitch receiver on your TV. They have a tow capacity limit and tongue weight limit. The tongue weight is often 10% of the tow limit so if your receiver was rated to tow 10,000 lbs, it could only handle a max. of 1,000 lbs tongue weight. However, the receiver rating could be less than 10,000/1,000 (with WDH) so you want to check that. I'm not familiar with Yukon's. Did they have a factory receiver or did you have one added?
You need to know what your actual tongue weight is in order to properly size your WDH bars. You could very well be undersized and I suspect you are. If your bars are too small, you will not be able to correctly transfer weight to the steer axles. If you do not transfer enough weight back onto the steer axles, you could end up having a very dangerous scenario. With the front wheels being too light, you could end up not being able to steer the TV. If you hit a bump, that could cause you to lose control. Having a short wheelbase TV means that it is easier to have too little weight on the front wheels.
Who set up the WDH? Did the dealer do it? If so, look out. They typically don't take the time to set them up properly. Did a hitch shop do it? That would be better but may still be off. The best way to set up a WDH is to use scale weights to figure out the weights transferred to steer, drive and trailer axles and then you will know exactly what is going on and if you have to readjust anything. At the least, someone should be measuring the before and after TV fender heights.
There is a rule of thumb guideline for the length of trailer versus the wheelbase of the TV of 110" for the first 20' and 1 foot for each 4" of wheelbase after that. Using this, the max. TT for your TV would be 23'. You are 6' in excess of the guideline amount. You will thus have more sway and handling problems.
Do you have any sway control (or "anti-sway" device? You should not tow a TT of this length without it. You could use the low-cost add-on friction bars, something like the Reese dual cam setup, or a high end and expensive type). Don't tow without one....
Who said your TV was adequate for that trailer? If the dealer, that's one reason to have problems right there. They just want to sell you any unit and get your $$ and see you gone off their lot.
What have you got for a brake controller and is that set up properly?
IMHO, without knowing exact weights and some detailed specs on the TV, I would have to say that your tow vehicle is inadequate. The combined wt. is way over the GCWR limit and you are likely overloaded on tongue weight. You could try setting up your WDH better, but if the tow vehicle is undersized, no amount of hitch adjustment will make it safe.
Just my humble opinion. I hope you get something out of this thread that helps and leads you to towing safer.