What Did I Do Wrong?

[oe2x]

I was towing a double axle trailer with a Kubota L35 behind my F350 powerstroke. Approx. GVM - 9,000 lbs.
Everything was fine for the first 200 miles of the trip. I had loaded the tractor so that bucket rested on the front of the trailer and the front of the tractors rear wheels where almost in line with the back axle. The backhoe was up and within a few inches of the rear end of the trailer.

I was cruising along at about 60 mph and did a slight correction to my steering. All of the sudden the trailer started to sway back and forth - left to right. As I let off the gas and started to coast to regain control the swinging became like a drunken sailor. Fortunately it was around 12:30 AM on a four lane highway with no cars nearby. The trailer started to pull the truck and I found myself weaving back and forth across both lanes of the road. It finally stopped when I dropped down to about 20 - 25 mph. I white knuckled it to the grass to calm myself and check the tractor. All the tiedowns were tight and it didn't appear to have shifted.

What I'd like to know is if I had too much or too little tongue weight?

 

[hutch4472]

Thats typically caused by too little tongue weight. Also you probably have heard this but when the "tail waggin the dog" senerio happens you are supposed to apply more power to the drivers to get the trailer to fall back in line with the truck. Of course that is easier said than done AND you eventualy have to SLOW down.....so maybe thats what you were doing by backing off the throttle. Hutch

 

[oe2x]

you are supposed to apply more power to the drivers to get the trailer to fall back in line with the truck. Hutch

I heard about that technique today. It makes sense now... Honestly - in the heat of the moment, I'm not sure I could have the courage to speed up when all the senses tell me to slow down and pull over.

 

[hutch4472]

Yep, its easy to say, just like when driving truck, if you blow a front tire you are supposed to "mash the throttle" to help pull weight off the front end, then slowly back off the throttle.........can be tough to do in a split second.........also was the L35 yours? I have a 2000 L35, I really like it. Hutch

 

[oe2x]

I just bought the L35 yesterday and was bringing it home. It should be a good machine for my purposes. Just glad I didn't litter the highway with her last night.

 

[Joe1]

I would reload it the same way and slowly drive it to a weight station and weigh the entire loaded trailer, then weigh just the tongue weight. Severely uneven tire pressure could also cause a sway, but most likely it's inadequate tongue weight because of the backhoe on the tractor acting as a lever to lift the weight off the tractor front axle and thus lightening the tongue load.

One other thing might be that the trailer is not riding level, with the tongue to high. As the tongue goes up, the weight shifts back away from the tongue and also lightens the load on the front trailer axle and shifts the weight to the rear axle.

You may have to load the tractor backwards with the backhoe and bucket both down and load it a little more forward. With the correct hitch, the F350 should certainly handle the heavy tongue load.

Applying just the trailer brakes may also help to slow the sway and straighten out the truck/trailer.

 

[hutch4472]

SWEEEEEET!!!! CONGRATS!!!! Remarkable machine. One tough little sucker.....and fairly heavy for its appearance......I also tow with a F350, you definetly want to pull the tractor further up on the trailer next time......make the truck squat down a fair bit before you chain down the tractor. Of course mines a gooseneck so that works good for me, if you have a bumper pull then you obviously have to worry about lightening up the front too much also......in which case you may need a stabilizing hitch..........Hutch

 

[oe2x]

Joe,
This is excellent advice. I'll look into it the next time I put her on the trailer.
Thanks.

 

[oe2x]

Here are some picts of the build site. This week we broke ground. The excavator crew move a few thousand yards of dirt to create a driveway. I now have to have a 120' x 12' high retaining wall built to keep the driveway from falling into where the house will be.

 

[hutch4472]

WOW looks like a dream site there. Must be nice to have access to money printers. An old co-worker of mine retired to that same area, he just finished his house and has a nice view of Mt Hood.