Have American and Canadian trucks got lifting airbags on the back axle
Are you referring to the tractor or trailer?
Some trailers do have an extra axle on the back for extra weight etc to have the 3 standard axles with a 4th lift axle in the form of a single tire on each end (I haven’t seen a tag axle with duel tires yet)
Some tractors do have the same thing, again for weight etc but both are not recognized in Canada I believe so have to be lifted at all times up here and can or must be down in the states (I never run into the states so I’m not sure)
Trailers do have lifts on the standard axles which may be lifted when empty, just like in Europe.
Tractor drive axles are not liftable but as said, can have a tag axle for use in the states
Hope this helps
Just the tractor unit back axle, not a lift axle as such just air bags lift
American tractors usually have tandem drive axles with air bag suspension. You can let the air out of the bags but it won’t lift the axle up. Some dump trucks and heavy haul tractors that have an extra axle do have the option to lift that axle up when not needed. Some trailers have air bags but no lifting axles but most have the old metal leaf springs.
remy:
American tractors usually have tandem drive axles with air bag suspension. You can let the air out of the bags but it won’t lift the axle up. Some dump trucks and heavy haul tractors that have an extra axle do have the option to lift that axle up when not needed. Some trailers have air bags but no lifting axles but most have the old metal leaf springs.
. . . Yeah, old being key . . . Currently pulling an old 1986 A-train!
Jeeze, how do they get away with running these old things now days 
So most tractor units can’t lift or drop their 5th wheel when hooking up a trailer
Yes they can. They can let the air out of the tractor air bags when dropping then airing up the bags will lift a low dropped trailer (as long as you can get under it) but if the trailer was dropped too high you can’t lift the fifth wheel above normal ride height.
Had air lift axles on my btrain one on each trailer, and two lifts on my tri axle trailer