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Engine/Gear Parameters
Top Gear Ratio
Top Gear Minus One Ratio
Top Gear Minus Two Ratio
Description:
The Top Gear Ratio parameter refers to the Eaton Top 2
Gear Ratios that are used by the ECM to decide when
to energize the Shift and Lockout solenoid outputs
(required for the Eaton Top 2 feature) when shifting
between the top two gears in vehicles equipped with
Eaton Top 2 transmissions. These parameters are Top
Gear Ratio, Top Gear Minus One Ratio, and Top Gear
Minus Two Ratio. These parameters have no effect if
the Transmission Style parameter is not programmed
to Eaton Top 2, however they must be correctly
programmed if it is programmed to Eaton Top 2.
Top Gear Ratio
This ratio identifi es the highest gear ratio for an Eaton
Top 2 Transmission. The programmable range is shown
in the table below. Note that for Gear Fast Run Slow
(GFRS) ratings the default value should be 0.731.
Top Gear Minus One Ratio
This ratio identifi es the second highest gear ratio for an
Eaton Top 2 Transmission. The programmable range is
shown in the table below. Note that for Gear Fast Run
Slow (GFRS) ratings, the default value should be 0.856.
Top Gear Minus Two Ratio
This ratio identifi es the third highest gear ratio for an
Eaton Top 2 Transmission. The programmable range is
shown in the table below. Note that for Gear Fast Run
Slow (GFRS) ratings, the default value should be 1.00.
Available:
C-10, C-12, C-15, C-16, C11, C13, C15 heavy duty engines
Range:
Engine Minimum Maximum Cat
Default
C-10, C-12, C-15, C-16,
C11, C13, C15
0.000 3.750 0.000
All three ratios share the same range above.
Note: The XX appearing in the transmission model
number refers to (x) 100=Nominal Torque Capacity.
For example, RTLO-14613A has a Nominal Torque
capacity of 14 (x) 100 or 1400 lb ft. The transmission
model designation and other transmission identifi cation
information are stamped on the transmission tag on the
lower left side near the front of the transmission.