okay i am in question of my ways and i home to be told i am right but if not please send me right.
i am now the training instructor for tractor trailers we have a small fleet but training people that may have never drove a pickup but has a car!
what i am asking you guys(ladies too!) is if i am right in saying these:
1) the landing gear is to be 1-2 inches off the ground when uncoupling(unless itis a really heavy load then i understand to lower all the way)
reason for the statement - the fifth wheel will tilt when it does that it will sit in the trailer on the ground nicely if you are going slow in the forward direction.(!) and #2 reason is when the next operator hooks up to the trailer that you dropped just as above this will raise the trailer slightly when it locks into the fifth wheel allowing you to test the fifth wheel to see if itactully locked buy trying to pull forward with out damaging the landing gear doing so?
2) do you guys/ladies believe in once disconnected you pull the fifth wheel out from under the trailer and stop with the trailer above the rear axle (just behind the fifth wheel) allowing the trailer to land on the frame rails if the landing gear fails?
now part two to that question if you using a tractor that the frame rails are lower than your rear tires should you pull out far enough that if the landing gear should fall it will send the front of the trailer down on the tops of you far rear tires ?
that is kinda two sided and i kinda wonder what would be worse?
any input would be great thanks -arick
need your opinion ! (all seasoned truckers)
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1. I would only drop an empty trailer 1-2 inches above the ground. The reason I would do this empty and not loaded is simple. (a) The tires when loaded ride lower that when you are empty. (b) If you drop a loaded trailer from that height you could damage the landing gear with the extra force put on them. (c) The last reason is if you manage to drop a loaded trailer 1-2 inches off the ground you may not be able to get back under it without causing damage to the nose of the trailer, or having to crank like mad in low-range on the landing gear to get it high enough to slide under. It's easier to lower a trailer than to raise one.
2. Some tractors are built to handle trailer riding up on their frame rails. They have what look like ramps welded to the frames. Even so I would not recommend letting a trailer ride the frame loaded. To answer your second part about getting the tires stuck, yes they would be stuck. This is also a sign that you didn't have your landing gear down far enough, and a good way to tear up tires.
I hope this helps. Have fun in your new position.
I'm a firm believer in dropping the gear all the way down until it touches the ground, not leaving it up an inch or two from contact. Reason for this is that I want to put the minimum stress on my clutch and drivetrain getting under the trailer, so the closer it matches my truck heighht, the easier it is going to be for me to get under it without any theatrics.
Second issue is that at certain times of the year, like the spring thaw, unless you are dropping the trailer on concrete, the ground can compress a bit and drop the trailer down a bit lower than it was to begin with. If you already start out with the trailer low, you can easily end up with a situation where you have to call a wrecker to lift a trailer that has dropped down into the ground. Once in a while in the spring, you will see the sight of a loaded trailer parked with the nose on the ground. it means that the landing gear was driven down right into the soft ground and the driver or the company is in trouble.
Correct way, drop the gear down until it touches solidly, lower the airbags on the truck to release as much of the weight as possible, and then pull out from underneath it with the minimal stress possible.
Burky got it right. Always lower the pads to the ground and don't drop the trailer. Loaded or not.
If loaded its a good idea to deflate the bags if you can. Many of the cheap company truck speced trucks do not have a suspension control in the cab.
The first tractor I drove had air ride with a dump valve that didn't work, I learned to pull out very slowly to let the height adjustment release some of the pressure.
My rule of thumb for cranking down the landing gear is to shut the motor off and listen for the suspension to start releasing air as the bags start to come up. with a spring suspension you can go a little less because it won't raise as much. and you obviously won't hear any air releasing.
The main reason for dumping the air is so you don't blow the bags from the sudden release of pressure. I hauled a few loads of grain with an air-ride hopper, i released the air when I started dumping the back hopper for the same reason.
A company mechanic instructed to lower to the ground, put in low range and raise an empty 10 turns and a loaded trailer 20 turns, you would hear air releasing at those points.
Dropping loaded trlr with feet lightly touching, and feet 1-2" on Mt's. I've done my share of cranking up 'recently loaded' trlrs--thk you!
Also, only time I ever blew an airbag was bobtailing around a lumpy/hole-ly dirt yard in Nogales just after dropping a loaded trlr and dumping air!
EDIT: When I said 'blew,' just had to be reseated at shop!
I blew out an airbag last year on a load. I guessed that I had about 100,000 poiunds inside the trailer, based on the time it took to unload it. I was doing some interplant work for a customer, haul was about 250 foot long, all I had to do was load, then take the load to the end of the building and unload it there into a different silo. They loaded the trailer way more than I expected, and while I was parked unloading, one of the rear air bags exploded. Finished unloading, took the truck to the shop and had the bag replaced while I borrowed a different tractor to unload the last load that was left there. Luckily, there was someone at the shop and we had the parts since this happened on a Saturday about 3 am.
I will usually drop the gear within an inch of the ground, then use my dump valve and pull out (if I am dropping on concrete pad or concrete lot). If I am dropping in a dirt lot, then I crank the gear all the way down and then pull out.
The reverse is, if I am backing under a trailer and I can tell it's been dropped a mile in the air, then I will just get under the trlr enough so that the nose is above the fifth wheel. Then get out, crank up the gear so the trlr is sitting on the 5th wheel, and then back under and do a tug test.
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