Allison Transmission 4700

NOTE:Acommoncauseforretarderperformancecomplaintsis
incorrecttransmissionuidlevel.Fluidlevelmustbesetcorrectly
formaximumretardereffectiveness.Aslittleas2liters(2quarts)
toohighortoolowcanreduceretardereffectivenessandincrease
transmissiontemperature.Referto5.8PERIODICFLUIDLEVEL
CHECKS.
NOTE:Theretarderrequiresabouttwosecondstoreachfullcapacity.
Besuretoanticipatethisdelaywhenusingtheretardertoprevent
unnecessaryservicebrakeapplicationsduringnon-emergencystops.
NOTE:Whenthetransmissionuidorenginewatertemperature
(anOEMoption)exceedsprogrammedlimits,retardercapacity
automaticallyreducesgraduallytominimizeoravoidsystem
overheating.
CAUTION:Observethefollowingcautionswhendrivingavehicle
equippedwitharetarder:
•THERETARDERWORKSONLYWHENTHEENGINEISAT
CLOSEDTHROTTLE.
•OBSERVETRANSMISSIONANDENGINETEMPERATURE
LIMITSATALLTIMES.Selectthelowestpossibletransmission
rangetoincreasethecoolingsystemcapacityandtotal
retardationavailable.
•IntheeventofOVERHEATING,DECREASETHEUSEOF
THERETARDER;USETHESERVICEBRAKESTOSLOW
THEVEHICLE.
•OBSERVETHERETARDER/SUMP“OVERTEMP”LIGHTto
besureitrespondsproperlytoretardertemperature.
Table4–7.TypesofRetarderControl
TypeDescription
AmountofApplication
Separateapplypedal
ZerotoFullapply
Manual
Handlever
*
Sixlevelsbasedonleverposition
Automatic
Auto“FullOn”
*
“FullOn”whenclosedthrottle
sensed
75