Minn. Stat. § 169.828
No vehicle alone nor any single vehicle of a combination of vehicles shall be equipped with more than four axles unless the additional axles are steering axles or castering axles; provided that the limitation on the number of axles as provided in sections 169.823 to 169.829 shall not apply to any vehicle operated under permit pursuant to section 169.86. No vehicle alone nor any single vehicle of a combination of vehicles shall exceed the posted weight limit for a single vehicle.
A vehicle or combination of vehicles equipped with one or more variable load axles shall have the pressure control preset so that the weight carried on the variable load axle may not be varied by the operator during transport of any load. The actuating control for the axle shall function only as an on-and-off switch. The provisions of this subdivision do not apply to any farm truck registered prior to July 1, 1981, under section 168.013, subdivision 1c, for 57,000 pounds or less. This subdivision does not apply to rear-loading refuse-compactor vehicles, except that any refuse-compactor vehicle having a tridem rear axle must comply with this subdivision before being issued a special permit under section 169.86, subdivision 5, paragraph (h).
Minn. Stat. § 169.828
1981 c 321 s 4; 1982 c 424 s 42; 1982 c 617 s 11-13; 1983 c 198 s 9; 1986 c 398 art 13 s 6-9; 1986 c 452 s 20; 1Sp1986 c 3 art 4 s 13; 1991 c 112 s 4; 1991 c 333 s 18, 19; 1992 c 578 s 7-10; 1994 c 635 art 1 s 16; 1998 c 372 art 1 s 8; 2000 c 433 s 1; 2001 c 156 s 1; 2001 c 213 s 10; 2002 c 364 s 13; 2010 c 320 art 2 s 4