Pulling Empty Boat Trailer??

Is it unusual to pull your empty wakeboard boat trailer for any appreciable distance? I have a 2004 Mobius LSV which comes with a Boatmate single axle, disk brake trailer. Normally, we launch the boat and I park the trailer and tow vehicle in the nearby parking lot. No problems. However, a couple weeks ago, now that my 16 year old son is somewhat responsible with the boat, we decided to let him and his friends take the boat out alone. However, I don't allow him to tow the boat since he is a very beginner car driver who has enough problems backing the car up, let alone backing a trailer. So, we towed the boat to the launch area from our storage (about 10 miles), launched the boat, and I proceeded to tow the trailer, empty, back to my house (about 10 miles). The trailer weighs something like 1,000 lbs and the boat is somewhere around 3,000 - 3,500 lbs. The ride home was one hell of an adventure. As I would approach stopping, from about 10 mph down to 0 mph, the trailer would start violently bucking to the point that it felt like it would rip the hitch off my Ford Explorer. Once home, I contacted the dealer service dept and they indicated that it might be the brakes hitting too hard, not correctly compensating for the empty load. I took the boat and trailer in to the dealer and they proceeded to work with Boatmate, discovering that one of the bearings had been installed incorrectly and was failing. They replaced the bearing and some other parts. However, I spoke with the guy from Boatmate and he indicated that when they tow empty, they have a brake lockout mechanism they insert and that I could take the brake lockout key and tape it inplace to lockout the brakes. (Note, I find it highly unusual that the bearing could have been that badly failing that I could tow the boat and trailer to the dealer 15 miles without any indication whatsoever of a problem). So, the next time we tried it, I did not tape the brake lockout key and had some bucking occur with the empty trailer, but not quite as bad except for one section of the road that is a downhill portion right near our house. For the trip back to the lake to pick up the boat, I taped the brake lockout key in place and found that I still had some bucking at stopping. I noticed that if I went to the back of the empty trailer and lifted up on the rear, the entire frame seems to flex like a diving board. I believe that when I hit a bumpy area or a downhill area the tires bounce and the trailer flexes causing something like a diving board or trampoline effect.

Long story short, this is not what I anticipated when towing empty. However, it seems that towing empty is a very unusual thing to do for boaters (from the dealer and Boatmate). Is this really something unusual or something I should not want to do?? Boatmate is investigating my problem, but no clues so far.

I don't have much help to offer but I've towed just a trailer from my cabin in northern Idaho to Seattle which is about 400 miles with no problems. To me it seems like your situation is a but unusual. My trialer may have been a little stiffer too, because I had some of the bucking as you described but it wasn't very severe at all.

I have an older trailer that doesn't have its own braking system and have never had problems towing it alone...I used to keep my boat in wet dock so I'd have to drive 30 miles to the lake w/o the boat if I wanted to pull the boat out of the water. For stability purposes I drove a little slower than normal, other than that I never had any trouble. but it sounds like your problems are coming from the braking system (which I don't have).

My earlier trailers didn't buck empty--but this year's MC trailer for the X-Star has a bucking problem too. The two things that helped--locking out the brakes (which you have done) and raising the tow ball. MC recommends 18' of clearance from the ground to the ball.

Another thing you might look into is balancing the wheels on your trailer. Now I know a lot of folks don't balance their trailer wheels, but since I did, my trailer has pulled appreciably smoother. Like you said, the trailer flexs quite a bit when unloaded, so the more it gets upset (by out of balance wheels, potholes, etc.) the more it will jump around on your tow vehicle.

Speaking as a person who used to work for an MC dealer. I have towed empty trailers sometimes up to 4 hours and have noticed the bucking... But its just because the brakes are set up to stop a certain amount of weight and when empty its essentially too much brakes for the weight of the trailer. There really isn't any harm to the trailer or the brakes, its just annoying to have the trailer bounce around on you. I would suggest one of two things. If you are towing the trailer empty raise the ball on your trailer 2-3 inches, this will put less weight on the tounge and more on the axles which will make it handle as if there is more weight on the trailer, or you could take some big sand bags with you and throw them on the trailer when you tow it empty. Other than an annoyance there really isn't any trailer damage you can do as far as I know. Be more aware around corners because an empty trailer CAN flip over if its bouncing and you are cornering quickly... Just a thought.

Does anyone elses MC trailer brakes rattle when hitting small bumps as much as mine? the dealer said it was normal, but I am not so sure.

Paul, my 01 MC tandem trailer had rattles, ends up the bolts were breaking that hold the caliper and the assembly was dragging. They fixed under warranty. My 2 03 MC tandem trailers do not make any noise, except for the metal rollers on the prop cage.

Disk brakes, all 3 trailers bucked when empty. Just part of it. If I towed long distance I would jump the wires and activate the 5th to release brakes.

(Message edited by prostar205v on October 20, 2004)

Mike (bigdeal), you may have something there. The folks at Boatmate have been conferring with the folks at UFP (parts supplier) and they believe this may be a case of out of round tires which would primarily show up at low speeds. Boatmate is sending two new, balanced tires/wheels to my dealer for switch out - hopefully fixing the problem.

it is your brakes locking up. you must have disc brakes on the trailer. they're set up to stop 5000 lbs, not 1000. if your trailer plug has 5 leads, put in a relay and switch in the cab that will allow you to override the brake lockout when needed. someone can post a circuit for this if you need one. you should override when towing the trailer empty to prevent bucking, and when driving down long hills to prevent overheating.

"MC recommends 18' of clearance from the ground to the ball."

WOW, 18 FEET?! ;)

trace,
It is not the brakes. I indicated in the posting that I have a key taped in that locks out the brakes. Also, the UFP coupler has a shock absorber mechanism that adjusts for the weight of the trailer. The disk brakes are activated by the trailer pushing the coupler together - with the shock absorber, it takes more weight before the the coupler is pushed together, thus with less weight, unless a hard stop occurs, the shock absorber keeps the brakes from hitting too suddenly. However, the brake lockout key completely prevents the coupler from sliding forward, thus no brake activation. It is the equivalent to not being able to push in your brake pedal on your car.

I have a Boatmate single axle trailer that does the same thing when I tow empty with my Jeep Cherokee, which has an extemley low trailer hitch. Once I towed the trailer with a friends 4Runner which has a substancial higher hitch and the bucking was much improved. I have been told that balancing your trailer tires can help as well.
Note: I had the exact same problem with my last trailer which did not have any brakes.

i'm familiar with surge brakes, and i had a UFP coupler on my old boat. the key on mine did not completely restrict the movement of the coupler, and it would buck sometimes as well.

here's something you can try next time you tow empty: flip the 5 way plug over so that the brake lockout is connected to the parking lights, and turn on your parking lights. tow it around a bit and see if the bucking still occurs.

i don't see how this could be tire balance if it only occurs at slow speeds, and when coming to a stop?

good luck.

http://www.mymastercraft.com/forum/viewtopic.php?t=65

Found this on another site that sounded like what you are dealing with.. Hope this helps..

trace,
The major problem with flipping the plug is that your left and right turn signals are now reversed. Also, someone in another thread mentioned that if you do that, you would cause the solenoid that overrides the brakes to burn out - that it is not meant to be "on" for extended periods of time.

On the other hand, I did see where there is about 1/8th - 1/4th inch play in the coupler when the brake lockout key is inserted. I don't know if that slight amount would be enough to still allow activation of the brakes, but I mentioned that to Boatmate and they are going to test it out.

In the meantime, Boatmate is sending two new tires and wheels, balanced, to my dealer to swap out my trailer tires and wheels.

Larry,
Thanks so much for posting the MasterCraft thread. It sounds exactly like what I am experiencing. While it doesn't sound like MC has any solution either, one person there posted a link to Arrow Trailer in Canada where you can buy a dealer lockout device that I can use instead of taping the brake lockout key in place. I ordered it today ($5.95 Canadian).

(Message edited by wakeshoe on October 26, 2004)

No problem bud I never tow my trailer too far (unloaded) except to park the truck. Now that I have been reeding into this I think I may get one myself.
The only thing that bugs me with my traler is when I come to a stop and then take off it jerks back like there is slop or play in the reciever. I checked the master cylinder and it does need some break fluid so I thought that I would try that first. Anyone ever heard of this and if so what did you do to fix it.
Thanks

If you have the same UFP A-60 Coupler I do, there is about an inch to 1.5 inches of play in the coupler which is how the brakes get activated (i.e., when you hit the brakes, the trailer weight pushes the coupler forward (it is a slide mechanism), which pushes on a rod that activates the trailer brakes). When you come to a stop, the coupler would remain slid forward. After you start up again, the coupler would slide backward, releasing the trailer brakes. That distance is about 1-1.5 inches. I always ease forward until that slack is out then accelerate (I usually just take my foot off the brake and the car moves slightly forward, taking up the slack, while I am stopped). That may be what you are feeling, but it sounds like you might be experiencing more than that amount of slack. If it is, I have no clue.

(Message edited by wakeshoe on October 26, 2004)

That may be all it is but man is that annoying when you take off a little too fast. I do the same as what you said let my foot off the break and slowly accelerate seems to work ok. I was just curious if anyone else experiences that.
Later..

i wasn't recommending leaving the plug flipped all the time, just temporarily to test the theory. if it stops the bucking, i'd install the override switch i mentioned above if it were my rig. i don't know if the lockout solenoids are rated for continuous duty or not, but i wouldn't be surprised if they are not. it's $40 for a new one if you do cook it, which IMO is cheap for the increased safety of eliminating the severe bucking you described.

trailer tires should definitely be balanced if you tow > 50 mph.

just trying to help, bro. good luck.

Larry I have the same experience with my trailer when its low on fluid. Gets much better when its topped up, still there to a degree but much better.