Sorry for bringing up a 2 month old thread, but just saw this thread for the first time and decided to tell my story. Warning: a long story.
This happened about 40 years ago while I was fairly young and still had a lot to learn about proper set up. I had a 1973 Suburban, 3/4 ton, 4 speed, 4X4. I had bought it used and it cam with a very heavy built drop hitch which was just about the right height for my 1969 Kit trailer, 19 feet with single axle. So I just installed the proper ball and went with it. It towed fine and had no issues at all for the first year or so.
Our three children were getting to that age when they wanted to take their bicycles along on our camping trips. My wife and I also had our own bikes and so I needed to come up with a way to easily haul five bicycles along on our trips. At the same time, decided to come up with a way to mount the trailer spare tire to the trailer as opposed to carrying it in the back of the suburban. The back wall of the trailer was one of those that curved in towards the front the higher up the wall you went. I built a nice rack out of square tubing that was curved to hug the profile of the rear wall. It was mounted securely to the frame and turned out looking really nice and was very strong and stable. I mounted the spare tire to the rack and made a removable bike rack that attached to the new rack. Had a way to haul all of the bikes that was easy to use.
First couple of trips with the new set up and everything worked great. Didn't notice any difference in the way the trailer towed. Thinking back, realize those first couple of trips were close to home, meaning very little highway driving. We then took a long trip across the State. Most of the time I didn't drive all that fast as with 4.10 gears in the suburban, the mileage really went down above 60 mph. Was on a section of highway and got stuck behind a truck going 45 to 50 mph. Came to passing lane which was somewhat short which meant I needed to really speed up to get around the slower truck. Was going well over 65 mph on a down hill section while making the pass. Got around the truck okay and was slowing down back to normal driving speed. All of a sudden, the trailer started whipping back and forth and was actually moving the heavy suburban all around on the road. I hit the manual trailer brake control to apply full braking to the trailer while stomping down on the gas pedal in an effort to keep the suburban in front of the trailer and hopefully regain control. At the same time I yelled for the kids to get on the floor as we were likely going to wreck (this was before anyone used seat belts.) It worked and I soon regained control and began to breath again. For the rest of the trip, I made sure to keep the speed under 60 mph.
As I tried to run over in my mind what had happened and why, I kept going back to the rack I had added to the back of the trailer. I sorta knew that in general you needed a certain amount of weight on the tongue of the trailer but obviously didn't yet understand all I needed to know as I didn't realize that the "little" weight I added to the back of the trailer could make that much difference.
After getting home safely, I made some changes to my set up. I cut off the heavy drop hitch setup modified what was left to add a receiver to the rear of the Suburban. That way, I could use the WD hitch I already had. I also made some changes to the trailer to move some weight forward to compensate for the weight of the rear rack.
Never had an towing issue with that trailer or any other trailer I have owned (and/or towed)since then I am now always aware of the need for proper tongue weight.
Several years later I was a witness of another very close call due to improper loading of a trailer. I was part of a motorcycle club that had a club trailer that contained a 4 wheeler and other tools for clearing and maintaining trails. I was towing my trailer to go camping and my friend was going to tow the club trailer up to the same area so we could do some trail work. We met at the place the club trailer was stored and my friend was already hooked up and nearly ready to go when I arrived so I didn't have a chance to even see the setup before we left. My friend was in front of me as we headed to the mountains. As we got well clear of town and where you can finally get up to good speed on the highway, the club trailer started whipping all around. I was directly behind and could see it well. It was a very close call and my friend was lucky he didn't wreck before he got stopped. He had assumed he had blown a tire or something and stopped as soon he he could get under control to check it out. I parked behind him and also got out. My friend was surprised to fine that nothing looked out of place and that the tires were okay. I explained to him what I suspected and asked him to open the back of the trailer. As I suspected, the 4 wheeler was only in the trailer far enough to close the rear doors. I told my friend we needed to move the 4 wheeler forward a little and that it would then be okay. I went on to retell my own story about the rack on my trailer to convince him that it would be okay after moving the 4 wheeler. Anyway, we did move the 4 wheeler and after that the trailer towed fine for the rest of the trip.
Lesson learned and then reinforced several years later.
