Volvo 431–03 Service Manual
ServiceBulletin
VolvoTrucksNorthAmerica
Greensboro,NCUSA
ThisServiceBulletinreplacesServiceBulletin,
431–03“I-ShiftTransmission,Designand
Function”dated1.2008.
Transmission,DesignandFunction
Trucks
DateGroupNo.ReleasePage
4.2010
43103
DesignandFunction
I-ShiftTransmission
1(38 )
T4021207
TheI-Shifttransmissionisatechnologicallyadvancedautomatedmechanicaltransmission,
designedspecicallytoworkinconjunctionwithVolvo’snewfamilyofheavy-dutydiesel
engines.Inordertoworkasatotalpackage,theI-Shiftisprogrammedwitheachengines’
efciencymapandisofferedwithdifferentsoftwareoptionstofullleachoperatorsneeds.
•“Transmission,Mechanical”,page2
PV776-88949834
USA39152
VolvoTrucksNorthAmerica
ServiceBulletin
Transmission,Mechanical
General
AllvariantsoftheVolvoI-Shifthave12forwardspeeds
andupto4reversespeedsdependingonprogramming.
Itisasinglecountershafttransmissionbuiltupwitha
splittersection,amainsectionwiththreeforwardandone
reversegear,andarangegearsection.Itisanautomated
mechanicaltransmissionandusessynchronizersinits
splitterandrangegearsbutnotinthemainsection.The
mainsectionutilizesacountershaftbraketomeshgears
andequalizeshaftspeedsasneeded.Asingledisc
automatedclutchsystemisutilizedinplaceofatorque
converter.TheI-Shiftisa"twopedal"transmissionand
doesnotrequireaclutchpedal.
TheI-Shiftusescompressedairandelectricalsolenoids
toperformshiftfunctions,clutchcontrolandcountershaft
Date
4.2010
brakefunctions.Allofthesefunctionsaretimedand
controlledbythetransmissioncontrolmodule(TCM).A
dedicatedairtankisneededonthevehicletosupplyairfor
thesecomponents.Theairisplumbedtothetransmission
viaasupplylineandisdistributedtotheothercomponents
internally.Theaircontrolsolenoidsarehousedinthe
transmissioncontrolhousingandintheclutchcontrolvalve
assembly.
AllVolvoTruckmodelswillbeavailablewiththis
transmissionincludingtheVT ,VNSeries&VHDvocational
trucks.MultipleI-Shiftmodelswillbeofferedtosupportthe
powerrangesoftheenginesaswellasofferingdifferent
geararrangements.
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43103
No.Release
Page
2( 38 )
AT2512CATO2512CAT2812CATO3112C
Operation
ForwardSpeeds
EnginesAvailable
OverallRatio
TopRatioDirect1.00:1
Weightlbs(kg)597(275)597(275)610(281)610(281)
Operation
ForwardSpeeds
EnginesAvailable
OverallRatio
TopRatioDirect1.00:1
Weightlbs(kg)614(279)614(279)627(285)
TwoPedalTwoPedalTwoPedalTwoPedal
12121212
D11/D13D11/D13
14.94:115.04:114.94:115.04:1
Overdrive0.78:1
AT2612D
TwoPedalTwoPedalTwoPedal
121212
D11/D13D11/D13
14.94:115.04:115.04:1
ATO2612DATO3112D
Overdrive0.78:1Overdrive0.78:1
D16D16
Direct1.00:1
Overdrive0.78:1
D16
VolvoTrucksNorthAmerica
ServiceBulletin
TransmissionIdentication
Eachtransmissionhastwoidenticationtags.Oneisfound
onthetopoftheclutchhousingandtheotherisfoundonthe
MakeVolvo
Type
Transmission
NomenclatureA—Automatic
AT2512C,ATO2512C,AT2612D,ATO2612D,AT2812C,ATO3112C,andATO31 12D
T—Transmission
O—Overdrive
25—TorqueCapacity2500Nm(1850ft-lb)
26—TorqueCapacity2600Nm(1900ft-lb)
28—TorqueCapacity2800Nm(2050ft-lb)
31—TorqueCapacity3100Nm(2300ft-lb)
12—Numberofforwardgears
CorD—DesignLevel
Date
4.2010
backoftherangehousing.Thetransmissionversioncan
bereadilyidentiedbythefollowingnomenclaturetable.
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No.Release
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GearRatio
GearratiosforAT2512C,A T2612D,AT2812C,ATO2512C,
ATO2612D,ATO31 12C,andATO31 12Dareasshownin
thetable:
12gearedAT2512C,A T2612D,
Gearselection
1st
2nd
3rd
4th
5th
6th
7th3.44:12.70:1
8th2.70:12.12:1
9th2.08:11.63:1
10th1.63:11.28:1
11th1.27:11.00:1
12th1.00:10.78:1
ReversegearR1
ReversegearR2
ReversegearR3
ReversegearR4
AT2812C
14.94:111.73:1
11.73:19.21:1
9.04:17.09:1
7.09:15.57:1
5.54:14.35:1
4.35:13.41:1
17.48:113.73:1
13.73:110.78:1
4.02:13.16:1
3.16:12.48:1
12gearedATO2512C,ATO2612D,
ATO3112C,ATO3112D
VolvoTrucksNorthAmerica
ServiceBulletin
TransmissionConstruction
Thetransmissionhasthreemainparts:aclutchhousing,
mainhousingandrangehousing.Theclutchhousing(1)
alsoformsthefrontwallofthetransmissionhousing.The
mainhousing(2)containsthemain,counterandreverse
Date
4.2010
shaftsalongwiththeselectorassemblywhichisintegrated
intothetransmissioncontrolhousing.Therangehousing
(3)containstherangeplanetarygearassemblyandoutput
shaft.
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4( 38 )
1Clutchhousing
2Mainhousing
3Rangehousing
W4002905
VolvoTrucksNorthAmerica
ServiceBulletin
Date
4.2010
Group
43103
No.Release
Page
5( 38 )
Themaininternalpartsinthetransmissionaretheinput
shaft(1),mainshaft(2),rangegearwithselectorunit(3),
countershaft(4),oilpumpwithreverseshaft(5),control
housingwithselectorunit(6)andifequipped,apower
takeoff(PTO)driveshaft(7).
Thetrailingwheelforthereversegear,themaingearsand
therangesectionssungeararelocatedonthemainshaft.
Therangesectionalsoincorporatesplanetarygearsthat
areintegratedwiththeoutputshaft.Thecountershafthas
xedgears.
1Inputshaft
2Mainshaft
3Rangegearwithselectorunit
4Countershaft
5Oilpumpwithreverseshaft
6Controlhousingwithselectorunit
7DriveshaftforPTO
T4021728
VolvoTrucksNorthAmerica
ServiceBulletin
Synchronization
•Thesplitgear(A)issynchronized.
•Themaintransmissionhousinggears(B)are
non—synchronized,butinsteadutilizeacountershaft
braketoequalizeshaftspeedsandmeshthegears.For
moreinformationsee,
page11.
•Therangegear(C)issynchronized.
Date
4.2010
Group
43103
No.Release
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6( 38 )
T4021404
RangeGear
Therangegearssynchronizationliesoutsidetheringgear,
reducingtheunit’slength.Thelargesynchronizationarea
resultsinshortselectiontime;thewideplanetarygearsoffer
strengthandthehelicalgearsresultinaquietplanetary
gearoperation.
Rangegearassemblywithselectorunit
W4002906
VolvoTrucksNorthAmerica
ServiceBulletin
ControlHousingAssembly
Thecontrolhousingassemblycontainsthetransmission
controlmodule(TCM),shiftsolenoids,countershaftbrake
solenoid,gearpositionsensors,oiltemperaturesensor,
shaftspeedsensors,theshiftforksandtheirshiftcylinders.
Whenagearisselectedusingthegearselector,these
componentsworkinconjunctionwiththeenginecontrol
module(ECM)toreducetheenginetorquetoasuitable
level,beforethecontrolhousingshiftsthetransmissionto
neutralandthentotheselectedgear.Thesolenoidsare
usedtocontrolpressurizedairtocylinders,thatperform
theactionofchangingthegears.Thecontrolhousingalso
containsandcontrolsthecountershaftbrakesolenoid.This
solenoidcontrolsairpressuretothebrakeassemblywhich
aidsinsynchronizingtheshaftspeedstomeshthemain
gears.Afterthetransmissionhasbeenputintoneutral,the
ECMbeginstoadjustenginespeed(RPM)toaccommodate
theselectedgearaftertheshifttakesplace.
Date
4.2010
Group
43103
No.Release
W4002915
Page
7( 38 )
Thecontrolhousingcoverhastwoelectricalsockets
andalsocontainstheTCM.
1Vehiclecommunication
2Clutchcylinder
W4002936
VolvoTrucksNorthAmerica
ServiceBulletin
Thecontrolhousingcovercontainsninesolenoid
valvesthatcontrolthepathofpressurizedair:
2.
Solenoidvalve2ndgear
LR.
Solenoidvalve,lowrange
3.
Solenoidvalve3rdgear
HR.
Solenoidvalve,highrange
B.
Solenoidvalve,brake
LS.Solenoidvalve,lowsplit
R.
Solenoidvalve,reverse
HS.Solenoidvalve,highsplit
1.
Solenoidvalve1stgear
Page
8( 38 )
OverdriveTransmissions
Group
43103
No.Release
W4002918
Date
4.2010
2.
Solenoidvalve2ndgear
LR.
Solenoidvalve,lowrange
3.
Solenoidvalve3rdgear
HR.
Solenoidvalve,highrange
B.
Solenoidvalve,brake
HS.Solenoidvalve,highsplit
R.
Solenoidvalve,reverse
LS.Solenoidvalve,lowsplit
1.
Solenoidvalve1stgear
T4018189
DirectDriveTranmission
VolvoTrucksNorthAmerica
ServiceBulletin
Thefollowingshowsthelocationsofthefourparallel
cylindersandoneofthecylinderpositionsensors.
A.Splitcylinder
B.1/Rcylinder
C.2/3cylinder
D.Rangecylinder
E.Splitcylinderpositionsensor
Date
4.2010
Group
43103
No.Release
Page
9( 38 )
T4018494
Thefollowingshowsthelocationsoftheotherthree
cylinderpositionsensorsandthespeedsensors.
A.Rangecylinderpositionsensor
B.Countershaftspeedsensor
C.Mainshaftspeedsensor
D.2nd/3rdgearcylinderpositionsensor
E.1st/reversecylinderpositionsensor
T4018201
VolvoTrucksNorthAmerica
ServiceBulletin
Thefollowingshowsthelocationsoftheotherthree
shiftforks.
1.1st-Reversegearshiftfork
2.2nd-3rdgearshiftfork
3.Splittergearshiftfork
Date
4.2010
Group
43103
No.Release
W4002920
Page
10( 38 )
VolvoTrucksNorthAmerica
ServiceBulletin
CountershaftBrake
Thecountershaftbrakeislocatedatthefrontofthe
countershaftwithintheclutchhousing.Itisusedtostop
therotatingpartsinthetransmissionwhenastartinggear
isselected,whicheliminatestransmissionwearandnoise.
Thebrakeisalsousedwhenchanginggears,toaidin
synchronizingtheshaftspeedsforquickergearchanges.It
isactivatedbyasolenoidcontainedinthecontrolhousing.
Thesolenoidcontrolspressurizedairowtothebrakes
integratedpneumaticcylinderwhichappliespressureto
frictionandsteeldiscplates.
Date
4.2010
Group
43103
No.Release
Page
11( 38 )
Countershaftbrakelocation
Countershaftbrakediscs
T4021408
T4022010
VolvoTrucksNorthAmerica
ServiceBulletin
Clutch
AllI-Shiftequippedvehicleshaveasingledisc,drytype
clutch.Thepressureplateusedinthevehicleswillvary
dependingontheenginethatthevehicleisbuiltwith.
VehiclesequippedwiththeD11orD13engines,willuse
anonadjustablepressureplatewhiletheD16equipped
vehicleswilluseaselfadjustingpressureplate.Dueto
theselfadjustingnatureoftheD16’spressureplate,it’s
necessarytocagetheadjustingsystempriortopressure
plateremoval.Theadjustercannotberesetifnotcaged
properly.Allclutchandpressureplatesarereplacedin
matchedsets.
TheI-Shiftclutchisfullyautomatedandisactuatedbya
clutchcylindermountedbehindthepressureplate.This
automationincludesclutchprotectionthatisprogrammed
intothetransmissioncontrolmodule(TCM)software.Ifa
vehicleisheldstationaryonagradeusingtheaccelerator
ortoohighgearisselectedwhichallowsexcessiveclutch
slippageorload,a“clutchprotectionactive”warningor“high
clutchload”warningwillappearinthedriverinformation
display(DID)andanaudiblewarning.Ifthesewarnings
areignoredtheclutchwillslowlyengagetoprotectthe
clutch.Iftheacceleratorpedal(AP)isreleasedtheclutch
willimmediatelydisengage.
Date
4.2010
Group
43103
No.Release
Page
12( 38 )
T4012799
ClutchCylinder
Theclutchcylinderislocatedinsidetheclutchhousing.
Thisfullyautomatedcylinderencirclestheinputshaftand
isresponsiblefortheactuationoftheclutch.Compressed
airisusedtomovethecylinderasneededtoactuatethe
clutch.Thepressurizedair,isregulatedbytheclutch
controlvalvelocatedontheoutsideoftheclutchhousing.
Theclutchcylinderalsohousesthereleasebearing.In
situationswheretheI-Shiftisunintentionallyleftingear
andtheparkingbrakehasbeenapplied,thetransmission
controlmodule(TCM)willautomaticallygointoneutralafter
aperiodoffourminutes.Thisprovidesprotectionagainst
releasebearingdamageaswellascrankshaftthrust
bearingwearanddamage.
Aclutchcylinderpositionsensorismountedtotheoutside
ofthecylinder.Itisusedtomonitorclutchpositionand
clutchengagementpoint.Asasecondaryresponsibility
itisusedtocalculateclutchwear.Therearetwoclutch
positionreferencevaluesthatarenecessaryinmonitoring
theclutch.
1X1Value—Thisisthebaselinevaluesetwhenevera
newclutchisinstalled.Thisisdoneusingthescantool
byperformingthe“ClutchEngagementPointCalibration”.
T4021527
2X2V alue—Thisisthevaluethatrepresentsthepresent
positionoftheclutch.
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