General
Thissectionhasthedescriptionandrepairproceduresforthesteeringhousingandthesteering controlunit.Additionalinformationonpartsofthe steeringsystemareinthefollowingsections: SteeringAxle 1600SRM451(B024,C024),1600SRM 326(D004,D019,E007,F006,G006),1600SRM10
(A177,B177,C177),and1600SRM71(E008)and HydraulicSystem 1900SRM453(B024,C024), 1900SRM333(D004),1900SRM443(D019,E007), 1900SRM328(F006,G006),and1900SRM130 (A177,B177,C177).
Description
Thissectionhasadescriptionandtherepairproceduresformorethanonebrandofsteeringcontrol unit.SeeFigure1.Theunitsaresimilarinconstructionandoperation,withhoseconnectionsontheside atamanifoldorvalveblockassembly.SeeFigure2 orFigure4.Somemanifoldsalsohaveareliefvalve.
Thesteeringcontrolunitisahydrostaticunitthat iscontrolledbythesteeringwheel.Thecontrolunit isinstalledinahousingoronabracketatthecowl andisoperatedbythecolumnassemblyandsteering wheel.Thesteeringcontrolunithasacontrolsection andameteringsection.
Thesteeringsystemisahydraulicsystemthatdoes nothaveamechanicalconnectionbetweenthesteeringwheelandthesteeringaxle.Thecontrolofthe steeringisthroughahydrauliccircuit.
Ifthehydraulicpumpforthesteeringsystemdoes notoperate,steeringisstillpossible.Acheckvalve permitsthesteeringcontrolunittocontrolthesteeringcylinder.Thelifttruckisdifficulttosteerwhen thesteeringpumpisnotoperating,butthesteeringcontrolunitcanoperatethesteeringcylinderand makesteeringpossible.
Operation
Thesteeringcontrolunitisarotaryvalveoperatedby thesteeringwheel.SeeFigure1.Duringthesteeringoperation,thesteeringcontrolunitcontrolsthe directionofflowandamountofoilthatflowstothe steeringcylinder.Thesteeringcylinderintheaxle actuatesthesteeringlinkagetomovethesteertires. Hydraulicoilreturnsfromthesteeringcylinderto thesteeringcontrolunitandthenreturnstothehydraulictank.
Turningthesteeringwheelactuatesthreemain partsofthesteeringcontrolunit:(1)Thespoolfor thecontrolsection,(2)thesleeveforthecontrol section,and(3)therotorinthemeteringsection. Whenthesteeringwheelisnotmoving,thespool andsleeveareheldintheneutral(center)position bysprings.Duringthistime,oilflowsfreelythrough thesteeringcontrolunit.Theoildoesnotflowtothe steeringcylinder.
Asthesteeringwheelisturned,thespooljustbeginstorotate.Thespringstrytomovethesleeve tokeeptheneutralpositionbetweenthespooland sleeve.However,theforcenecessarytoturntherotorisgreaterthanthepressureofthesprings.The springsbegintobend,lettingthespoolmoveasmall
amountwithinthesleeve.Thespoolstopsmoving whenittouchesthecenterpin.Inthisposition,the holesinthesleeveandthespoolarealigned.Oilcomingintothecontrolunitflowstothemeteringsection. Morerotationofthesteeringwheelcausesthespool torotatethepin.Thisactioncausestherotationof thesleeveandtherotorinthemeteringsection.The oilthenflowstoonesideofthesteeringcylinder.Hydraulicoilfromtheothersideofthesteeringcylinderreturnsthroughthecontrolsectionofthesteeringcontrolunit.
Whenthesteeringwheelstopsmoving,themeteringactioninthemeteringsectionalsostops.The neutralpositionspringsreturnthesleevetotheneutralposition,stoppingoilflowtoorfromthecylinder. Thepressurestaysinthesteeringcylindertokeep thesteertiresinposition.Oilfromthepumpflows throughthesteeringcontrolunittothetankorother partsofthesystem.Toreturnthesteerwheelstothe straightposition,thesteeringwheelmustberotated intheoppositedirection.Thesteeringcontrolunit willoperateasdescribed,butallpartswillrotatein theoppositedirection.
Theupperendofthesteeringshafthassplinesforthe steeringwheel.Alargenutholdsthesteeringwheel ontothesteeringshaft.Thehornbuttonisthecover forthecenterofthesteeringwheel.Thelowerendof thesteeringshafthassplinesoratangtoengagethe steeringcontrolunit.Contactsatthehornbutton (seeFigure2),awireinthecolumn,andslipring contactsinthecolumnassembly(seeFigure1)allow forhornoperationbytheoperator.
Therearetwotypesofsteeringcolumnassemblies discussedhere;TypeAandTypeB.TypeAhasacolumnhousingthatisasupportforthemountbracket
TYPEASTEERINGCOLUMNASSEMBLY RemoveandDisassemble
CAUTION
Disconnectthenegativebatterycableoninternalcombustiontrucks.Disconnectthebattery connectoronelectrictrucks.Disconnectthe batterybeforeremovingthecovers.
1. Attachatagonthebatteryconnectorornegative cablestatingDONOTCONNECTBATTERY. Movethesteeringcolumntothemost-forward position.Removetheaccesscoverfromthe steeringcolumn.SeeFigure2andFigure3.
2. Puttagsforidentificationonthehydraulichoses atthesteeringcontrolunitsotheycanbeconnectedcorrectlyduringassembly.Disconnectthe hydraulichosesatthebottomofthemanifoldor valveblock.Installplugsatallhosesandportsto preventdirtfromenteringthesteeringhydraulic system.
ofthesteeringcontrolunitasshowninFigure3. TypeBhasamountbracketofthesteeringcontrol unitthatisthesupportforthecolumnhousingas showninFigure4.
Thesteeringcolumnassemblyisadjustableandheld inpositionbyalatch.Theassemblypositioncanbe changedasneededforoperatorcomfort.Anaccess coveronthesteeringcolumngivesaccesstothesteeringcontrolunithoseconnections.
3. Carefullyliftthehornswitchatthecenterofthe steeringwheelandpulltheswitchwireoutofthe steeringshaft.SeeFigure1.Pulltheswitchassemblyoutofthesteeringwheelanddisconnect it.Removethenut.Ifpossible,useapullerto removethesteeringwheel.
4. Puttagsforidentificationonthemetersand gaugewiresatthesteeringcolumnhousingso theycanbeconnectedcorrectlyduringassembly. Also,putatagonthehornwire.SeeFigure1. Disconnectallwires.
5. Removethecapscrewsthatfastenthemount platetothecowlandremovethesteeringcolumn assemblyfromthelifttruck.
6. Removethetwospringsforthelatch.Remove thetwocapscrews,nuts,washers,andspacersat thepivotpointsofthecolumnhousing.Remove themountplate.
LegendforFigure2
NOTE: H20.00-32.00F/FS(H440-700F/FS)SHOWN,OTHERSSIMILAR.
7. Removethefourcapscrews,washers,grommets, andspacersthatfastenthebracketforthesteeringcontrolunittothecolumnhousing.Carefullyremovethesteeringcontrolunit,bracket, andcolumnfromthecolumnhousing.Ifnecessary,removethelatchassemblyfromthecolumn housing.
8. Removethefourscrewsthatfastenthebracket andsteeringcolumntothesteeringcontrolunit. Donotlosethespacersorwashers.Removethe twoscrewsthatfastenthemanifoldorvalve blocktotheportsideofthesteeringcontrolunit. Ifnecessary,disassemblethesteeringcontrol unitasshowninSteeringControlUnit,Disassemble.
AssembleandInstall
1. Ifnecessary,assemblethesteeringcontrolunit asshowninSteeringControlUnit,Assemble.Installthemanifoldorvalveblockonthesteering controlunitusingnewO-rings.Ifremoved,installthelatchassemblyinthecolumnhousing. SeeFigure2andFigure3.
2. Installthesteeringcolumnandbracketonthe steeringcontrolunitasremovedduringdisassembly.Installthisassemblyinthecolumnhousing.Donotdamagethehornwirecontactorcolumngrommet(seeFigure1).Makesuretoinstallthegrommets,washers,andspacersasa soundisolatorforthesteeringcontrolunit.
3. Installthetwocapscrews,nuts,washers,and spacersatthepivotpointsofthecolumnhousingandmountplate.Installthetwospringsfor thelatch.Installthemountplateandcolumnassemblyonthecowlofthelifttruck.
WARNING
ThehydraulichosesMUSTbeconnectedtothe correctportsandfittingsorthesteeringsystemwillnotoperateasexpected.Thisoperationthatisnotexpectedcancausedamageor personalinjury.Makesurethehosesareidentifiedandconnectedcorrectly.
4. Installallwiresandhosesasremovedduring disassembly.Installthesteeringwheelandnut. Pushthehornswitchwireintothesteeringshaft andinstalltheswitchinthesteeringwheel.Installtheaccessplate,removethebatterytag,and connectthebatteryconnectororcable.
WARNING
Aftermaking repairs,donotextendthehands orarmsthroughthecenterofthesteering wheel.Ifth econtrolunitwasnotassembled correctlyorthehosesnotconnectedcorrectly, itcanrotatewithastrongforceandcauseseriousinjury.Ifthisactionoccurs,disassemble thecontrolunitandcorrecttheproblem.
5. Operatethesteeringsystemtocheckforcorrect operation andleaks.
Thank you very much foryourreading.Please Click Here Then Get MoreInformation.
NOTE: If there is no response to click on the link above, please download the PDF document first and then clickonit.
LegendforFigure3
NOTE: H8.00-12.00XL(H165-280XL)ANDH13.00-16.00XL(H300-360,H330-360XL-EC)SHOWN,OTHERSSIMILAR.
TYPEBSTEERINGCOLUMNASSEMBLY
RemoveandDisassemble
CAUTION
Disconnectthenegativebatterycableoninternalcombustiontrucks.Disconnectthebattery connectoronelectrictrucks.Disconnectthe batterybeforeremovinganycovers.
1. Attachatagonthebatteryconnectorornegative cablestatingDONOTCONNECTBATTERY. Movethesteeringcolumntothemost-forward position.SeeFigure4.
2. Puttagsforidentificationonthehydraulichoses atthesteeringcontrolunitsotheycanbeconnectedcorrectlyduringassembly.Disconnectthe hydraulichosesatthebottomofthemanifoldor valveblock.Installplugsatallhosesandportsto preventdirtfromenteringthesteeringhydraulic system.
3. Carefullyliftthehornswitchatthecenterofthe steeringwheelandpulltheswitchwireoutofthe steeringshaft.SeeFigure1.Pulltheswitchassemblyoutofthesteeringwheelanddisconnect it.Removethenut.Ifpossibletoinstall,usea pullertoremovethesteeringwheel.
4. Puttagsforidentificationonthemetersand gaugewiresatthesteeringcolumnhousingso theycanbeconnectedcorrectlyduringassembly. Alsoputatagonthehornwire.SeeFigure1. Disconnectallwires.
5. Removethescrewsthatfastenthecolumnhousingtothebracketforthesteeringcontrolunit. Carefullyliftthecolumnhousingandbushingoff thesteeringcolumnassembly.
6. Removethefourscrews,washers,isolator,and spacersthatfastenthesteeringcolumnandthe steeringcontrolunittothebracket.Removethe steeringcolumnfromthesteeringcontrolunit. Removethetwoscrewsthatfastenthemanifold orvalveblocktotheportsideofthesteeringcontrolunit.Ifnecessary,disassemblethesteering controlunitasshowninSteeringControlUnit, Disassemble.
7. Ifnecessary,removeallpartsofthelatchfrom thebracket.Ifnecessary,removeallpartsof thespringmechanismandpivottoremovethe bracketfromthecowlofthelifttruck.
AssembleandInstall
1. Ifnecessary,assemblethesteeringcontrolunit asshowninSteeringControlUnit,Assemble.Installthemanifoldorvalveblockonthesteering controlunitusingnewO-rings.Ifremoved,installthebracketandspringmechanismonthe cowlofthelifttruck.Ifremoved,installthelatch assemblyandspringmechanismonthesteering controlbracket.
2. Installthesteeringcolumnonthesteeringcontrolunit.Installthefourscrews,washers,isolator,andspacersthatfastenthesteeringcolumnandthesteeringcontrolunittothebracket. MakesuretoinstalltheclampinthecorrectpositionasshowninFigure4.
3. Carefullyinstallthecolumnhousingandbushingoverthesteeringcolumn.Installthescrews thatfastenthehousingtothebracket.
LegendforFigure4
NOTE: H2.00-3.00XL(H40-60XL),S6.00-7.00XL(S135-155XL),ANDS3.50-5.50XL(S70-120XL)SHOWN,OTHERSSIMILAR.
WARNING
ThehydraulichosesMUSTbeconnectedtothe correctportsandfittingsorthesteeringsystemwillnotoperateasexpected.Thisoperationthatisnotexpectedcancausedamageor personalinjury.Makesurethehosesareidentifiedandconnectedcorrectly.
4. Installallwiresandhosesasremovedduring disassembly.Installthesteeringwheelandnut. Pushthehornswitchwireintothesteeringshaft andinstalltheswitchinthesteeringwheel.Removethebatterytagandconnectthebatteryconnectororcable.
WARNING
Aftermakingrepairs,donotextendthehands orarmsthroughthecenterofthesteering wheel.Ifthecontrolunitwasnotassembled correctlyorthehosesnotconnectedcorrectly, itcanrotatewithastrongforceandcauseseriousinjury.Ifthisactionoccurs,disassemble thecontrolunitandcorrecttheproblem.
5. Operatethesteeringsystemtocheckforcorrect operationandleaks.
SteeringControlUnit
Disassemble
Disassemblethesteeringcontrolunitasfollows:
STEP1. Putthecontrolunitinavisewithsoftjaws.Makean identificationmarkonthelengthofthecontrolunit. Wheninstalled,removethemanifoldblock.
STEP2. Removethecoveronthebottomofthesteeringcontrolunit.
STEP3.
Removethespacer(ifused),thestator,rotor,andport plate.Putamarkonthestatorsothatthesameside willbetowardthebodyofthecontrolunitatassembly.RemovetheO-rings.Removethecentershaft.
STEP4.
Removethescrewforthecheckvalveassembly.Removethepartsforthecheckvalve.Forsomeunits, thecheckballisintheoppositeendofthecontrol unit.
STEP5.
Removethespoolandsleeveassembly.Removethethrustbearingassemblyfromthespool.Pushthecenterpin fromthesleeve.Carefullyremovethespoolfromthesleeve.Rotatethespoolslowlyduringremoval.Remove theringfromthesleeve.Removetheneutralpositionspringsfromthespool.
STEP6.
Wheninstalled,removethesnapring,bushing,O-ring,andsealring.Removetheoilsealfromthebushingor housing.
WARNING
Cleaningsolventscanbeflammableandtoxicandcancauseskinirritation.Whenusingcleaning solvents,alwaysfollowthesolventmanufacturer’srecommendedsafetyprecautions.
WARNING
Compressedaircanmoveparticlessotheycauseinjurytotheuserortootherpersonnel.Make surethepathofthecompressedairisawayfromallpersonnel.Wearprotectivegogglesoraface shieldtopreventinjurytotheeyes.
Cleanallthepartsinsolvent.Drythepartswithcompressedair.Donotdrythepartswithacloth.Makesure allsurfacesarefreeofscratchesandsharpedges.