CHASSIS INFORMATION — 10
248
2008 IMPERIAL
Periodic Inspections
The Allison MH Series requires very little
maintenance. Careful attention to the
fl
uid level,
electrical connections and hydraulic hoses is
very important.
The transmission should be kept clean for easy
inspection. Make periodic checks for loose bolts
and leaking
fl
uid. Check the condition of the
electrical harnesses regularly. Check the engine
cooling system occasionally for evidence of
transmission
fl
uid that would indicate a faulty
oil cooler. Report any abnormal condition to an
Allison Service Center.
Prevent Major Problems:
Help the control system oversee the operation
of the transmission. Minor problems can be kept
from becoming major problems if an Allison
Transmission Service center is noti
fi
ed when one
of these conditions occur:
1. Shifting feels odd.
2. Transmission leaks
fl
uid.
3. Unusual transmission-related
sounds (sound made by normal
engine thermostatic fan cycling
when climbing a long grade with a
heavy load are often mistaken for
transmission-related sounds).
4. The Check Trans indicator comes on
frequently.
TRANSMISSION FLUID & FILTERS
The transmission is
fi
lled with TranSynd
™
synthetic transmission
fl
uid at the factory.
TranSynd synthetic transmission
fl
uid extends
service intervals. A small tag has been attached
to the dipstick identifying that the transmission
is
fi
lled with TranSynd synthetic transmission
fl
uid.
Fluid and Filter Change Interval:
The transmission has two
fi
lters: a Main
fi
lter and a Lube
fi
lter. Follow the service
intervals listed in the transmission OEM
(Original Equipment Manufacturers) manual.
Fluid and
fi
lters may require changing earlier
than recommended in the transmission
OEM manual depending on the severity of
operating conditions. Fluid must also be
changed whenever there is evidence of dirt
or high temperature operation as indicated by
discoloration, strong odor or
fl
uid analysis.
Local conditions, severity of operation or duty
cycle will dictate more or less frequent service
intervals.
CAUTION:
DO NOT mix Dexron III
®
transmission
fluid with TranSynd
™
Synthetic
transmission fluid.
NOTE:
Refer to the Allison transmission
owner’s manual or contact an
authorized Allison service center for
fluid and both filters service intervals.
Proper Fluid Levels:
Transmission
fl
uid cools, lubricates and
transmits hydraulic power. Proper
fl
uid levels
must be maintained at all times. If
fl
uid level
is too low, the converter and clutches do not
receive an adequate supply of
fl
uid. If the
level is too high,
fl
uid can aerate. Aerated
fl
uid can cause the transmission to shift
erratically or overheat.
An
Oil Level Sensor (OLS)
is built into the
transmission. The
fl
uid level can be checked
easily and cleanly using the shift selector. Check
the transmission
fl
uid level before each trip and
after removing the motorhome from storage.
Fluid Level Check from the Shift Selector:
To Enter Oil Level Sense Mode:
Park the motorhome on a level surface.
Place the transmission in “
N
” and set
parking brake.
The transmission temperature must be at
operating temperature or an error code
will appear.
The motorhome must be stationary
and in Neutral for approximately two
minutes to allow the
fl
uid to settle in the
sump.
Located inside interior
engine access
070176
