Duff Norton Air Motor Jacks

If you are asking: "who can fix my Duff-Norton jack?", then you are in the right place!

Calumet Chicago is your Duff Norton Jack repair Expert Center! We have been repairing and rebuilding Duff Norton Air Motor Jacks for over 35 years.

air motor jacks in for Repair


As an Authorized Duff Norton Service center, our highly skilled and trained technicians restore your Duff Norton jacks to their original OEM status with certified Duff Norton parts. All jacks undergo multi-point testing, including load and sustained capacity testing to meet certification for return to our customers.

Calumet Chicago provides 100 lift and preventive maintenance services for all Duff Norton Air Motor Jack models

With our complete inventory of Duff Norton parts, we can return this workhorse back to operation quickly, to minimize your downtime. Many of today’s top Railroads, Railcar Service and Mining facilities rely upon Calumet Chicago to restore their valuable equipment to optimal performance levels.

Calumet Chicago sells NEW & Refurbished Duff Norton Air Motor Jacks. Give us a call today for all your Duff Norton Jack needs: 708-474-2343


Duff-Norton Air Motor Jacks are offered in seven models from 20 ton to 100 ton. These precision built, sturdy, dependable machines employ the time-tested basic screw principle with fool-proof, built-in rotary air motor. These Jacks can be synchronized for simultaneous operation through use of a “Y” connection. Used for raising and lowering freight cars, diesel locomotives and truck trailers.

Duff Norton Air Motor Jack Models (CMJ):

MODEL  144CMJ 132CMJ 126CMJ 536CMJ 528CMJ 326R 228R
STROKE  30" 18" 13-3/4" 25" 17" 14-3/8" 18"
TRAVEL TIME  2.6" PER MIN. 4" PER MIN. 6" PER MIN 2.6" PER MIN. 7.1" PER MIN. 12.9" PER MIN. 12.9" PER MIN.
CFM REQUIRED   155 CFM  180 CFM  200 CFM  120 CFM  170 CFM  170 CFM  180 CFM
LOWERED HEIGHT  44" 32" 26" 36" 28" 26" 28"
BASE DIAMETER  18"  13"  13" 15" 14" 14" 12"
HEAD DIAMETER   6-1/8"  6-1/8" 6-1/8" 5" 5" 4" 4"
WEIGHT  530 LBS 480 LBS 448 LBS 425 LBS 394 LBS 275 LBS 240 LBS




Design and Manufacturing Features:

  • Manufactured in compliance with ASME B30.1 (
  • Easy to move and spot with long transport handle and collapsible spotting handles
  • Up or down hand throttle control well guarded.
  • Position of lever clearly indicates direction up or down
  • Sturdy shell with large diameter base for stability under top-heavy loads
  • 10” diameter, 2 ½” face solid rubber-tire roller bearing wheels assure easy portability
  • Transport handle folds down and out of the way when jack is in use
  • Automatic shut off stops the motor when the lifting standard reaches the safe limit of its raised or lowered position
  • Screen in air hose connection easily removed for cleaning
  • Easy to lubricate through two convenient plugs in jack and one in air motor
  • Built in muffler
  • Ball bearing thrust and radial mountings throughout for easy action and long life

Safety Features:

  • A brake is provided on 50 and 100 ton jacks to prevent accidental lowering
  • The load is lowered entirely, as well as raised, by air motor so that the lowering speed is always under constant control, preventing slipping or sudden dropping of the load
  • The design of the jack prevents lowering or creeping under load in case of air failure due to disconnection or injury to the hose
  • Jacks are internally keyed to prevent standard from turning
  • Broad, sturdy base for stability Serrated forged steel top






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