It's just how they were ordered. They may have been purchased to pull single axle doubles trailers, or they may be purchased for light loads which don't require tandem axles.
You dont have to pull any axel
pull the caliper bolts and the pull the cotter pin off the axel nut and then pull the axel out. Take the chain off the sprocket and then pull the tire straight out
A "mechanical front wheel drive" tractor has front-wheel-assist which means that not only the rear drive wheels pull the tractor ahead, but the front wheels also pull the tractor.
To pull things
To pull the trailer.
Depends on the specs of the tractor. The 6x4 tractor spec'd to never haul more than 80k gross and the 6x4 tractor spec'd to pull those B-train doubles and eight axle sleds in Northern Indiana and Michigan aren't running the same drivetrain, I can assure you of that.
loosen the cap and pull it slightly to the left
They plowed the field with the tractor. Even with the tractor they were almost unable to pull the car out of the ditch.
Trailer
Tractor tuggers are powered by fiery aircraft engines! They have to pull a load of 100 tons for 110 years in special competitions. Tractor tuggers pull as heavy as 100 family cars.
you just pull it out you just pull it out