e r3~.APo!TheEngineering Society~ ForAdvancing Mobility ,...,......... LandSeaAirandSpace 400COMMONWEALTH DRIVEWARRENDALE, PA15096 872263 Automatic Transmissions for HeavyMilitaryTrucks Gordon F.Danhof TwinDisc,Incorporated TruckandBusMeeting andExposition Dearborn, Michigan November 16-19,1987Downloaded from SAE International by University of Edinburgh, Monday, August 27, 2018Theappearance ofthecodeatthebottomofthefirstpageofthispaperindicatesSAE's consentthatcopiesofthepapermaybemadeforpersonalorinternaluse,orforthepersonal orinternaluseofspecificclients.Thisoonsentisgivenonthecondition, however,thatthe copierpaythestatedperarticlecopyfeethroughtheCopyright Clearance Center,Inc., Operations Center,21Congress St,Salem,MA01970forcopyingbeyondthatpermitted by Sections107or108oltheU.S.Copyright Law.Thisconsentdoesnotextend10otherkindsof copyingsuchascopyingforgeneraldistribution, foradvertising orpromotional purposes, for creatingnewcollective works,orforresale. Paperspublished priorto1978mayalsobecopiedataperpaperfeeof$2.50underthe abovestaledconditions. SAEroutinelystocksprintedpapersforaperiodofthreeyearsfollowingdateofpublication. DirectyourorderstoSAEOrderDepartment Toobtainquantityreprintrates,permission toreprintatechnicalpaperorpermission touse copyrighted SAEpublications inotherworks,contacttheSAEPublications Division. AllSAl:p:pm ~'"abu",~Ud 4ndln4t:ud illtheSAEGloblllMobllir)'!hrt:b'm Nopartofthispublication maybereproduced inanyfonn,in anelectronic retrievalsystemorotherwise, withouttheprior writtenpermission ofthepublisher, ISSN0148·7191 Copyright 1987SocietyofAutomotive Engineers, Inc. thispaperIssubjecttorevision.Statements andopinions advanced Inpepersordiscussion aretheauthor'sandare hisresponsibility, notSAE's;however, thepaperhasbeen editedbySAEforuniformstylingandformat.Discussion willbeprintedwiththepaperif itIspublished InSAE Transactions. Forpermission topublishthispaperInfullor Inpart,contacttheSAEPublication Division.Personswishingtosubmitpaperstobeconsidered for presentation orpublication throughSAEshouldsendthe manuscript ora300wordabstractofaproposed manu­ scriptto:Secretary, Engineering ActivityBoard,SAE. PrintedInU.S.A.Downloaded from SAE International by University of Edinburgh, Monday, August 27, 2018872263 Automatic Transmissions for HeavyMilitaryTrucks Gordon F.Danhof TwInDisc,Incorporated Abstract Today'staskofproviding effective, stateoftheart tacticalvehiclestoallbranches ofourfightingforcesis coupledwithacutecost-awareness. Military decision­ makers,aswellastheirciviliansuppliers, areemphasiz­ ingtheprocurement ofstandardcommercial vehicles, or vehiclesthatdonotrequiregreatR&Doutlays. Thetermusedtodescribe theseacquisitions is NDI-Non-Developmental Items.Thispaperreviews currentheavydutytransmission configurations, and showsmodifications thatmaybenecessary tomeet militaryrequirements. First,letmeexplainwhythisdiscussion isrestricted toautomatic transmissions forheavymilitarytrucks. TwinDiscofRacine,Wisconsin, hasalwaysbuilttrans­ missions inthehigherpowerranges.Hence,wecan hardlyqualifyasexpertsforlighttrucktransmissions. Nowtosetsomeparameters. Whatisaheavyduty military truck? Whatdoesthemilitaryrequireinheavy military transmissions? Andwhatisthedutycycleof theseheavymilitarytrucks? TheU.S.Armyiscurrently projecting itsneeds, makingmarketsurveys, andwritingspecifications for thefollowing typesofheavyvehicles: I.Aheavydutytanktransport tomovetheM-I Abramsmainbattletank.Thisvehiclewillhave aGVWof 80,000to90,000Ibs.,andaGCW, including aloadedsteerable trailer,of210,000 to230,000Ibs. 2.Aheavydutymedium equipment transport capableofhaulingapayloadof48to55tons. Thispayloadwillconsistofmilitaryconstruc­ tionequipment, including crawlertractors, bulldozers, crawlercranesandscrapers. 3.Fourvariations offlatrackdesigntrucks,capa­ hIeofhauling8and16'12tonpayloads. These truckswillhaultrailersalsocarrying8and16'12 tonpayloads respectively. Theflatrackdesigniscalledapalletized loadingsystem,andcan unloa