Peterbilt Medium Duty Trucks Operator's Manual after 1-07

Operating Instructions
OPERATING THE TRANSMISSION
Introduction
Your Medium Duty is equipped with either a manual or automatic
transmission with special features and gearing to meet
your particular needs. It is important for you, the driver, to
understand how your particular transmission is operated. To
do this, you have two sources of information: this Operator's
Manual and the transmission manufacturer's Driver/Operator's
Instruction Manual. Because of the variety of different
transmissions installed in Medium Duty vehicles, operating
procedures for your particular transmission are not included
in this manual; therefore, you should read and understand
both manuals. Read the general guidelines and instructions
that follow and read the specific instructions contained in the
transmission manufacturer's manual that is included with
your vehicle.
NOTE: You will find a shift pattern diagram in the
cab. Check to be sure you know the correct
sequence for your particular transmission.
Operating Manual Transmissions
Operating the Transmission
If your truck has an automatic transmission, go to page 71.
6, 9, 10, and 11–Speed Manual
The 6–speed synchronized manual transmission has 6 forward
speeds and 1 reverse. The 9–speed transmission has 9
forward and 2 reverse speeds, consisting of a 5–speed low
range section and a 4–speed high range section.
For specific instructions on operating one of the optional 10-
or 11-speed transmissions, consult the transmission manufacturer’s
Driver/Operator Instruction Manual.
Transmission Warm–Up
In cold weather [below 32°F (0°C)], you may find shifting
sluggish when you first start up. Transmission warm-up is
especially important at this time, but it is always a good idea
to warm your transmission oil before starting out on the road.
To warm the transmission lubricating oil during engine warmup:
Medium Duty (R10/06) Y53-6008 – 67 –