OK, what causes fish tailing?
It must have something to do with how the load is setup on the trailer.
I pulled the tractor to a field that needed mowing, and noticed the trailer started fish tailing if I got over a certain speed.
So, I maintained that speed. No big deal.
I finished mowing, loaded back up, and off I went.
Something was loaded differently, though. This time I wasn't able to get up nearly as fast as the first time.
So, is fish tailing caused by the load being too far forward, too far back, too much on the left or right?
It's got to be something.
Reading through the posts it seems you are in the market for another trailer to haul your tractor with FEL and mower. Here are some facts and issues I discovered on a recent trailer purchase.
New licensing rules in Texas require any trailer with a gross loaded weight greater than 4,500 lbs to have at least two wheel brakes. The trailers have to be inspected before a license can be issued.
So you have an
L4400 that weighs 3400 lbs.
Front End Loader 1,000 lbs ??
Five foot shredder 500 lbs ??
So lets say your rig with everything attached and full of fuel is 5,000 lbs. Good so far?
So you need a trailer that is rated to haul 5,000 lbs minimum. My 18 foot bumper pull weighs 2,100 lbs, does not have brakes and is registered for 4,500 lbs. That leaves me with 2,400 lbs that I can haul legally and safely. It can handle my
B7510 nicely.
My
L3901 weighs 2,800 lbs. FEL add (just guessing) 1,200 lbs. Five foot shredder 500 lbs. So I am up to 5,000 lbs as well. (give or take a few pounds). When hauling the tractor is required to be chained at 4 locations (fuzzy on that). Loader has to be chained down (like flat on the trailer deck). Shredder has to be chained down flat on the deck. That whole rig flat on the deck takes up 99% of my 20 foot trailer deck.
So if you have to raise your FEL and your mower to balance the load on a less than 20 foot trailer then you can't possibly legally or safely haul your tractor as pictured in some of your posts.
Do you have a class III hitch attached to the frame of the truck? If not then are you pulling from the bumper alone. Most of the limitations I have read on bumpers limit you out at 5,000 lbs gross trailer weight and load on the trailer.
You are already experiencing fish tailing with a shorter trailer. I would venture a guess that the mower hanging out over the rear is a contributing factor as well.
I found on craigslist a 20 foot shop built trailer for sale. I paid $2200 for it. $480 to bring it up to DOT standards to be able to pass inspection. $350 for decking. $300 for heavy duty aluminum ramps. It took four months to get this trailer licensed after purchase. I had to have it inspected by law enforcement, then inspected for DOT compliance, sent photos off to DMV and applied for a vehicle identification number. It carries my tractor and shredder no problem. Four wheel brakes makes me feel like I can stop it in an emergency. No fishtailing. I have hauled 4 pallets of grass on it with no issues. I have it registered for 10,000 lbs gross. It weighs 2,300 lbs which gives me 7,700 lbs for cargo legally. The two 5,200 lb axles handles the weight great.
If I had it to do over again I would bite the bullet, go straight to Load Trail and buy a 20 foot (or longer) tilt bed trailer with 2 5,200 lb axles and not have to go through the process of registering a home made trailer. Tilt bed because handling ramps gets old and tiresome. Load Trail because they build an excellent trailer and have a great warranty for about the same as some of the other brands.
If you go with one of those run of the mill 18 foot trailers with two 3,500 lb axles I am thinking you will be in the same predicament as you are now.