Peterbilt 348 2017 - Page 161

OPERATINGTHETRANSMISSION
DuringNormalDriving
Ifyouwanttoshiftdirectlyintoanygear
otherthanrstorreverse,depressthe
clutchpedalonlyfarenoughtorelease
theclutch.Fullydepressingthepedal
appliestheclutchbrakeandcould
causegearhang-up.
CAUTION
Becarefulnottoapplytheclutch
brakewhilethevehicleismoving.
Thepurposeoftheclutchbrakeis
tostopthetransmissionsothatyou
canshiftintoastartinggearwithout
grindinggears.Applyingtheclutch
brakewhenthevehicleismovingwill
rendertheclutchinoperative.
DoubleClutching
Whetheryouareupshiftingordown
shifting,itisbesttodoubleclutch.
Doubleclutchingiseasieronthe
transmissionandontheengine,
helpingyourvehiclematchengine
speedwithdrivelinespeedand
achievingclash-freeshifts.
Todoubleclutch:
1.Pushtheclutchpedaldownto
disengagetheclutch.
2.Movethegearshiftleverto
neutral.
3.Releasethepedaltoengage
theclutch.Thisletsyoucontrol
theRPMofthemainshaftgears,
allowingyoutomatchtheRPMof
themainshaftgearstothoseofthe
outputshaft.
a.Upshifts:lettheengineand
gearsslowdowntotheRPM
requiredforthenextgear.
b.Downshifts:pressaccelerator,
increaseengineandgear
speedtotheRPMrequiredin
thelowergear.
4.Nowquicklypressthepedalto
disengagetheclutchandmove
thegearshiftlevertothenextgear
speedposition.
5.Releasethepedaltoengagethe
clutch.
(03/17)Y53-6060-1C14-21
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