"R1" or "R2" REVERSE position - is used to back the truck. The Reverse Warning Horn is activated when either gear is selected. When selecting either reverse position, COMPLETELY STOP the truck and bring engine RPM to low idle before shifting from a FORWARD range to a REVERSE range or vice-versa. "R1" position should be used for normal reverse operation. This range selection utilizes the standard 5.12 : 1 gear reduction ratio. "R2" position may be used for job operations that would benefit from a higher speed reverse operation. This range selection utilizes a 3.43 : 1 gear reduction ratio.
COMPLETELY STOP the truck and bring engine RPM to low idle before shifting from "N" to "R1"; "R1" to "R2" ; "R2" to "R1" ; or from either position to "N ". "D" DRIVE - position. The transmission will shift to first gear and as truck speed increases, the transmission will automatically upshift through each gear to sixth gear operation. As the truck slows down, the transmission will automatically downshift to the correct gear. 5, 4, 3, 2 - positions. Road and load conditions sometimes make it desirable to limit the automatic shifting to a lower range. These positions provide greater engine braking on grades. The transmission will not shift above the highest gear selected.
When conditions improve, select position D for full range operation. 1 - Use this range selection when pulling through mud and deep snow, or when maneuvering in tight spaces, and when driving up or down steep grades where maximum driving power and maximum engine braking is needed. NOTE: As engine and ground speed increases, the transmission will automatically UPSHIFT to the gear range required up to the highest range selected. However, DOWNSHIFTS will not occur, regardless of gear range selected, until engine and ground speed are reduced to match the next lower gear range requirements.
(12) DO NOT SHIFT LIGHT This light comes on anytime the on-board computer finds a potentially serious problem in the system. The computer will cause the transmission to lock- in-gear and also to disengage the lockup clutch. These actions by the computer reduces the possibility of damage to the truck and transmission. The hold-in- gear feature prevents upshifts and downshifts when a problem is detected in the operation of the transmission. The hold-in-gear circuit permits the transmission to continue to operate in the gear it was in at the time the DO NOT SHIFT light and buzzer came "On". Selection of a different gear range will have no effect on the transmission.
The hold-in-gear circuit is released when the engine is shut-off. If the problem causing the DO NOT SHIFT light is still present when the engine is restarted, the transmission will be in " Neutral" and will remain in "Neutral" until the probem is corrected. HB4021 6/95 Operator Controls HB4-5