Towing a 5ver with a lifted trk

[96ccdd]

I am thinking of lifting my truck and installing a set of 305's. The problem is or maybe towing my 5th wheel camper. Any comments ?

Thanks

[saywhat]

While many of the newer fifthwheel campers sit up higher,towing one with a truck much higher than stock is a bad move.Most hitch manufactures as well as RV dealerships say to allow 6 inches clearance between the bed rails and camper to allow for uneven terrain.When the camper is hooked up to the tow vehicle it should be fairly leveled out for a good tow.My truck is stock and I only get 5 inches clearance when my Holiday Rambler is hooked up and leveled out.I have been on uneven ground where that clearance has disappeared fast. Jim

[DmaxMaverick]

By lifted, do you mean only larger tires, or a lift kit?

I tow a 12K TT and have 33" tires (285/75/16). It was pretty close before the tire change, and the increased tire height didn't help. Before I changed tires, I did have an incident that dinged my bed rails on a winding mountain road. I had to raise my fifth wheel receiver 1.5". The larger tires then increased the height another 1 - 1.5". Leveling the truck, with trailer attached, helped by lowering the rear by about 1/2". That still left me about 1.5" higher at the pin. The trailer has a slight rake to it, but not much. I've towed about 10K miles with it like that and have had no problems. In the future, I will be replacing my stock trailer tires with taller ones to compensate and get the trailer back to level. So far, trailer tire wear has been normal and brakes work evenly.


On the safety side, the type of axles you have is important.

If you have leaf springs, it is not as critical. They will balance the load to some degree, but are not designed to operate that way. They are designed to allow for uneven ground, not uneven trailer. Too much rake, and the rear axle will have more load on it, which effects tire loading, and brake performance.

If you have torsion bar axles, it is very critical that the axles have equal loading. There is no "balancing" designed in. If the trailer loads one axle more than the other, the result is exponential. 1/2" more load on one axle is 1/2" less load on the other. The torsion bars are very stout, and don't allow for much, if any. This could translate to a 500# difference between the axles on a 10,000# trailer. Most travel trailer axles are at or near max loading to begin with. The "relief valve" is the tires and brakes. Less weight on an axle requires the heavy axle to brake at the level of the light axle, or the light axle will lock the wheel when braking, while the heavy axle gets all the braking load. This can effect braking ability by as much as 50%. Not good.


Trailer height and rake also effect aerodynamics. Too much of either can cause economy to decrease, and the effects of wind and gusts can decrease control and increase sway. If both truck and trailer are too high, too much air gets under and decreases control and economy. It also raises the center of gravity.

An unlevel trailer can also effect the performance of appliances, like the refrigerator. If they are too far from level, they don't work well. It also causes fluids in storage tanks to transfer their weight.

Ideally, the truck and trailer should be level. At highway speeds, the lower, the better. Too often I see rigs traveling down the highway with the truck sagged in the back, and the trailer with a serious rake.

The bottom line:
If it's not much, and safety doesn't suffer, don't sweat it. Get it right as soon as you can. Be leary of bed rail clearances. If you never venture off the beaten path and are always on pavement, you can play it a little closer. Otherwise, allow at least 6" clearance when on level ground, 8" is better. If your receiver is solid (not a tilting type), you can get a little closer.

[tn09]

You can always get your axle on the trailer flipped. By flipping the axles you should be able to gain about 4-6 inches in height.

Check with your trailer place about getting the axle flipped. Basically, you are putting the leaf springs on top of the axle. Cost is some where around 500.00, since you will need to have some welding done (spring seat).

[dcalex]

There may be some breaking issues to consider also. I don't know if or how much those bigger tires will effect the ABS.....some say they will, others disagree.