For all vehicles manufactured, modified or retrofitted with |
liftable or variable load suspension axles after October 30, |
1991, liftable or variable load suspension axles are permitted |
only under the following conditions: only one liftable or |
variable load axle may be present on the truck tractor and |
only one liftable or variable load axle may be present on the |
semitrailer; liftable or variable load axles must be located |
on the vehicle so that they are legally part of the tandem |
axle group or tri-axle group as appropriate; and the axle |
weight rating of liftable or variable load axles must conform |
to the expected loading of the suspension and must be 20,000 |
pounds or more. |