Axles

[kb0zke]

As we research, I'm finding that most FW units have axles rated at 7-8,000 pounds, yet the gross weight is over 16,000 pounds, sometimes several thousand pounds over. I also read many complaints about axles, which leads me to believe that a pair of 8000 pound axles really isn't enough for a coach that weights more than 16,000 pounds, and a pair of 7000 axles certainly isn't.

I understand that a FW will have some weight on either the hitch or the legs, depending on whether or not it is attached to the truck. When the rig is sitting still I can see that there wouldn't be a problem. When going down the road, though, everything is moving up and down and sideways. Might those dynamic loads overload the axles?

Some manufacturers offer 7000 pound axles as standard, and 8000 pound ones as an upgrade option. Doesn't that say that the trailer really needs the stronger axles, but it will work until the warranty runs out with the 7000 pound ones?

[JIMNLIN]

I've heard more complaints on less than adequate tires matched to the axles than the axles themselves.

One big reason someone would go with a higher rated 8000 lb axle axle is greater braking capacity over the 7000 lb axle.

IMO a upgrade axle option doesn't say the OEM axle needs to be stronger.

[Half Dimes]

Since about 20-25% of the weight of an average fifth wheel rests on the pin (or the legs) that means on a 16,000 lb rig, about 12,000 to 12,800 lbs ends up on the axles. I would agree that dual 7K axles don't give much leeway but are adequate. I also agree with the previous poster that tires are usually the weakest link in the whole equation.