Allison Transmission T 270

IfaPTOispresent,itisnormallymountedoneithertheleftorrightsideof
the3000Seriestransmission.Onthe4000Seriestransmission,thePTOis
locatedontheleftsideoronthetopofthetransmission.ThePTOdrivegear
isengine-drivenandthereforeprovidesdirectenginepower.ThePTOcanbe
operatedwhenthevehicleiseithermovingorstopped.
ThePTOgearisinconstantmeshwiththedrivegearintheconverter
housing.However,thePTOmayeitherbeconstant-drive(outputalways
powered)orclutch-driven.WhenthePTOisclutch-driven,theclutchispart
ofthePTO,notthetransmission.Aclutch-drivenPTOispoweredonlywhen
thePTOclutchisengaged.
AllAllisonTransmission-equippedvehicleswithPTOenabledhave
engagementandoperationalspeedlimitsprogrammedintotheTransmission
ControlModule(TCM)tohelpprotectPTOequipment.Besurethelimits
forPTOengagementandoperationalspeedsarenotexceeded.Consult
thevehiclemanufacturer’sliteratureforthesespeedlimits.Somespeed
limitshavedefaultvalueswhichareprogrammedoutoftheoperatingrange
andneedtobesetforyourparticularPTOdutycycle.Consultyourvehicle
manufacturertoseeifyourtransmissionhasbeenprogrammedandwhat
operationallimitshavebeenestablished.
Whentheprogrammedengagementspeedisexceeded,thePTOwillnot
engage.ThePTOengagementmustberetriedafterthespeedhasbeen
reduced.Whenoperationalspeeds(eitherengineortransmissionoutput)are
exceeded,thePTOdeactivatesandthePTOengagementprocessmust
berepeated.
3.8DRIVINGONSNOWORICE
WARNING:Usingtheretarderonwetorslipperyroadsmaycause
lossoftractiononthedrivewheels—yourvehiclemayslideoutof
control.T ohelpavoidinjuryorpropertydamage,turntheretarder
enabletoOFFwhendrivingonwetorslipperyroads.
NOTE:Theretarderisdisabledautomaticallywheneverthevehicle
ABSisactive.However,intheeventtheABSmalfunctions,itis
recommendedthattheretarderenableswitch,ifequipped,be
disabled.
Ifpossible,reducevehiclespeedandselectalowerrangebeforelosing
traction.Selecttherangethatwillnotexceedthespeedexpectedtobe
maintained.
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