Mack 'R' Model

The Mack 'R' model was a Class 8 heavy-duty truck first introduced in the early 1960s by Mack Trucks, to replace the very successful Mack 'B' Model. Its production ran for 40 years until the RD model was discontinued in 2002 and the RB and DM models were discontinued in 2005. The first R models introduced were powered by Mack Thermodyne diesel and gasoline engines. In 1973 the R cab was given a makeover to include a deeper rear wall for more room and a new dashboard design.

As with all heavy duty trucks, they may be ordered numerous ways (chassis cab & install your own body, box truck, flatbed, stake bed, wrecker, etc.), single or tandem drive axle, tractor with fifth wheel, heavy duty (heavier than 'normal' class 8)/off-road, etc.

They were available with different brand engines/transmissions. Unlike most truck manufacturers, Mack also offerred their own Mack brand engines & transmissions in addition to Caterpillar or Cummins.

The 'R' model had its own 'sub-series' of different styles available. Some of them continued on after the original 'R' model was discontinued. Below is a listing of SOME different 'R*' models:

• R - Standard model
• RB - Set back front axle (except in New Zealand - see NZ Mack RB)
• RD - Heavy Duty R
• RM - 4x4 Municipal/maintenance chassis
• RMM - 6x6 Municipal/maintenance chassis
• RS - Western R series, S stands for steel frame
• RL - Western R series, L stands for Aluminum frame
• RW - Western series, replaced by the Mack Super-Liner
• U - Short hood offset cab
• DM - Heavy duty U
• DMM - All wheel drive DM
• Chassis numbers (GVW Rating):
  • 4xx -
  • 6xx -
  • 7xx -
  • 8xx -

Note: the xx is the place holder for the engine code.

• Suffix letters:
  • T - Tractor
  • S - Six wheel chassis
  • L - Light weight components
  • X - Extreme duty