Runaway truck and trailer with me driving the tractor on it!

[JOHNTHOMAS]

Yesterday loaded my near new L3901 with grapple attached to front to take to Barlows for blowing front hydraulics fuse problem. Mechanic looked at it on trailer but asked me to leave it till they could get it in shop and find the short that kept blowing the fuse. Should be fixed today for pick up.
As I loaded my tractor on the trailer I noticed it started moving on me!!!! I thought earthquake!!! I'm on a hill and by the time I got the tractor in position on the trailer my truck had started going downhill and went about 10' till it ran into a big 6" high monster rock which stopped the front tire. Yep, in park and emergency brake on.
When I unloaded it at Barlows on near level gravel lot the trailer and truck slid about 2'!
I talked to Gary about it and also mentioned how trailer seemed to be swaying some while bringing tractor to shop. He reminded me of several years ago when I had an Avalanche and was loading or unloading a L3240 and the front tires of my truck lifted off the ground and started sliding until he got in the truck and mashed the brake pedal to keep the truck from moving.
I've been transporting BXs, Bs, Fs, ZDs and small Zs but this is only my second L which is much heavier than the others sooooo it is lifting the front end of the truck when it goes up the ramp onto the trailer which then has little to no real brake griping hold on the ground with just the two rear tires on the ground. I'm posting this as a warning to others with heavier equipment. Don't do it alone unless it's absolutely necessary or have the truck heading up hill. Or a monster truck with lots of front weight which isn't a Toyota Tacoma 4wd. Take someone with you to mash the brake pedal and a helper is handy to work the other side of the trailer when locking the tractor down to the trailer if you can get them out of the truck.:laughing:.

 

[check]

Try putting a couple of bottle jacks under the rear corners of the trailer, and jack them up slightly.

 

[LD1]

Are you sure if was lifting the front up in the air? Sounds backwards. With a The size tractors you mention, shouldnt be any where close to enough tongue weight to make the front light.

BUT......when loading heavy stuff, before you get all the way on the trailer and position. It LIFTS the tongue of the trailer....making the back of the truck light. And unless you are in 4wd or have park brake set.....the ONLY thing holding your truck when in park is the rear tires.

I have no issues with my my tractor and rig......but when loading the 18000# backhoe or a similar weight D3 cat on the GN.....those are heavy enough that without the tail of the trailer blocked (some trailers have tail jacks for this) it will lift the rear tires completely in the air.....and leave the front tires to freewheel.

 

[Ford850]

Why wouldn't it have the rear wheels locked if it was in park, and the emergency brakes were applied? Aren't both of those locking the rear axle? Either way, a jack or block on the rear of the trailer (while loading) should correct the problem.
edit: I see LD1 corrected the lift question. He's right it would indeed lift the rear not the front.

 

[TMGT]

I usually just keep a peice or 2 of 6x6 to throw under the back of the one trailer if necessary (other has supported ramps).

Reminds me of the time I was hauling a decent load of gravel in the dump trailer and they loaded it a little lighter then normal on the tongue, drove fine but I didn't have enough traction to pull into the driveway off the steep gravel road in front of my property.
Put the truck in park and set the e-brake, hopped out to lock the front hubs and as soon as I let of the brake the truck started sliding down the hill!
Well crap, now I'm stuck half way up a long steep hill in 2wd and can't move or get out of the truck, luckily I was able to back up enough to find a spot that kinda held it long enough to get out and lock the hubs (although i did have to chase it down the hill just a little).

Lesson learned, when towing heavy, lock hubs on the flat road before the hill!

 

[check]

Also, check your parking brakes. They are surprisingly wimpy on a lot of vehicles, especially after some mileage has been put on them.

 

[CobyRupert]

Try putting a couple of bottle jacks under the rear corners of the trailer, and jack them up slightly.

:thumbsup:
This will prevent trailer lifting rear wheels.

(If the front wheels were lifting, it would not roll in Park. Unless you have a front wheel drive truck or 4WD with rear drive shaft removed.)

 

[s219]

Lots of threads about this here on TBN. Best solution is to block up the back of your trailer so that when it squats, it does not lift the rear of the truck off the ground. Parking brakes are only on the rear wheels of a vehicle, and if it's RWD (or 4WD but fronts not engaged) then the transmission park/in-gear will only apply to the rear wheels too. The fronts are free and won't do a darn thing.

I've never been able to lift the rear of my truck, but I still block the rear of the trailer when loading because it makes everything so much more stable and safe. It also prevents you from turning the trailer into a teeter-totter and placing massive amounts of bending stress on the frame and hitch that it's not meant to deal with.

As for the trailer stability when towing, it probably means your tongue weight was not correct. Would be as simple as re-positioning the tractor on the trailer until it's in a safe zone. With an L3901 that has no implements, you'll need at least a 16' flat deck to have the proper range. Better would be 18' of flat deck, and certainly if you have implements.

 

[Spindifferent]

I use two scissor jacks at the rear of my trailer when loading/unloading to prevent the trailer from lifting the rear of the truck:

Ultra-Fab Ultra Scissor Jack - 24" Lift - 6,5 lbs Ultra-Fab Products Camper Jack UF48-9796

 

[Gary Fowler]

I have had the rear wheels lift and the truck and trailer take off down hill when loading my LS on an incline. After doing this once, I bought some jack stands to put under the back of the trailer before loading. This solved the problem.

I cant see any way that loading any equipment would raise the front wheels. You would only get this if you overloaded the front of the trailer but again, I think the back bumper might drag the ground before the front wheels lifted and even if they did, the rear wheels is what the parking brake acts upon.

I never really thought about putting my truck in 4 WD to stop the rolling but I think that would work since lifting the rear wheels would really put some weight on the front tires for traction.