Allison Transmission T 280 - Operating down Steep Grades (Rear-Discharge Mixer); Using 2 Nd Reverse (4700;4800 Only)

3.11OPERATINGDOWNSTEEPGRADES(REAR-
DISCHARGEMIXER)
CAUTION:Withthistransmission,theservicebrakesmustbeused
whenbackingaloadedrear-dischargemixerdownagrade.Buttoo
muchbrakeapplication,particularlyonanunpavedsurface,can
lockthefrontbrakesandreducesteeringcontrol.Acrashcouldthen
occur.T ohelppreventinjuryorpropertydamage:
1.Driveforwarddownthegradeandthenexitbybackingupthe
gradewhenyoucandoso.
2.Ifequipped,usethetrailerbrakewhenbackingthemixerdown
agrade.Donotusethetrailerbrakeasaparkingbrakeonce
thevehicleisatthebottomofthegrade.
3.Ifatrailerbrakeisnotavailable,backthemixerdownthe
gradebymodulatingtheservicebrakestocontrolandmaintain
asafe,steadyvehiclespeed.Avoidabruptstopsandstarts.
3.12USING2
ND
REVERSE(4700/4800ONLY)
Selectedcalibrationsforthe4700/4800modelsofferanoptionfortworeverse
gears–astandardreversegearratioof4.80(shownasR2intheselector
display)andtheoptionaldeeperreverseratioof17.12(shownasR1inthe
selectordisplay).
TheAllison2
nd
Reversefeatureofferstheseoperationalbenets:
•Greatercontrolandenginebrakingduringoperationonsteepgrades.
•Moremaneuverabilitywhenoperatinginconnedspaces.
•Slowcreepcapabilitywithhighenginespeeds.
Referto4.1SELECTINGRANGEand7.0SHIFTSELECTORS
COMPONENTSANDFUNCTIONSforadditionalinformation.
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