By David Skora AAS68RCS68RC 6-Speed6-Speed

What’s InsideA465 orAS68RC 6-SpeedtheDon’t be surprised if, in thenear future, you step into thecab of some medium-dutytrucks, such as an NPR, and see a shiftcolumn indicating up to six speeds.No, this isn’t some sort of clutchlessby David Skorastandard transmission: It’s the AisinSeiki 6-speed automatic transmission the same unit that ATRA’s RandallSchroeder introduced in the September,2008 issue of GEARS.This article will review some ofthat material, provide additional information that applies to NPR trucks, andthen cover additional information tokeep these units rolling.Dodge calls this transmission theAS68RC. In NPR trucks it’s calledFigure 14040Dave1208.indd 40GEARS December 200811/18/08 8:31:04 AM

Figure 3: AT Over Temp Lightan A465. The specifications are prettyimpressive. Most units will be behindCummins diesels when installed in DC andDM 3500 Dodge trucks or the Isuzu dieselengine in the NPR trucks.As Randall pointed out, this unit isbuilt for heavy-duty use. The maximumengine torque rating is 730 lb-ft. The stockCummins 6.7L TD engine is currentlyrated at 565 lb-ft. The 4-cylinder Isuzu5.19L engine is rated at 440 lb-ft.CAUTION: Some aftermarket products can increase the diesel engine’s output, which could affect the durability of thetransmission.Figure 22008 BUYERS GUIDEQUALITY TRANSMISSIONREBUILDING EQUIPMENTSuperFlow TransDyno SF-66KShown withmanualconsole.The convenience, reliability, versatility and ability to test virtually every transmission on the road, including the new Allison models. Handles hydraulicallyand electrically shifted transmissions, foreign and domestic, in FWD, RWD andAWD configurations. Monitors and tests virtually every aspect of transmissionperformance, under simulated road load conditions, before the transmissionis installed supported by the accuracy and superior documentation of theexclusive TDAC (Transmission Data Acquisition & Control) System.TCRS Torque Converter Test and Rebuild SystemsExcellent profit center for transmission repair shops orstand-alone startups and smartest way to save timeand prevent costly comebacks.Single Gun Auto Weld AlignerStandard of the industry. And choice of thebig three — Ford, GM, Daimler-Chrysler.Air-operated collets. Patented auto-tackand auto-weld. Do “bowl buildups” andweld on impeller hubs. TAC 12 controlpanel lets you automatically controlnumber of tacs and duration.TCRS Torque Converter Balancerwith automatic weight indexing,runout compensation mode,push buttom polishing and betteraccuracy and repeatability thanever before.SuperShifterThe durable in-car testerRugged solid state electronics.Impact-resistant housing. Testsmost late model transmissions.Controls the transmission from inside the car.Tests Solenoid current/resistance. Operator ID and Date/Timestamp. Embedded Bluetooth for external device connectivity.Check out converters BEFORE you ship orinstall with HUB RUNOUT INSPECTIONUNITS. And, ensure your converter quality(after welding) with AIR TEST STANDS fordiagnosing leaks.www.superflow.com IXON 3TREET ES -OINES )! s PH OR GEARS December 200840Dave1208.indd 414111/18/08 8:31:28 AM

What’s Inside the A465 or AS68RC 6-Speed; Part IIGross CombinedVehicle Weightmeans the maximumweight (load) isbased on the totalweight of the vehicleplus the chassis andalso the weight ofany trailer beingtowed.Figure 4: Check Trans LightReady to Shift to a BetterInsurance Program?Get into Gear withHeffernan Insurance Brokers.We offer:Property/CasualtyEmployee BenefitsGarage Liability/Garage KeepersMedical/DentalProperty/Tool CoverageVision/LifeAutoDisabilityWorkers CompensationHR AssistanceContact us today!Property/CasualtyEmployee BenefitsEarl VanBuskirkearlv@heffgroup.comJani De La Rosajanid@heffgroup.comPaul Willspaulww@heffgroup.comShauna oup.comLicense #0564249ATRA program facilitated byHeffernan Insurance Brokers and Brant Watson.4240Dave1208.indd 42Dodge typically rates this transmission/chassis combination for 26,000lb GCVW (Gross Combined VehicleWeight*). The NPR trucks may havea GVW rating of 12,000, 14,500 or17,900 lbs. Check the rating tags on thechassis/frame to be sure of the ratingfor the vehicle you’re working on. Youmay also find a PTO unit attached orjust a blank plate, and some units arebolted to a 4WD transfer case.* Gross Combined Vehicle Weightmeans the maximum weight (load) isbased on the total weight of the vehicleplus the chassis and also the weight ofany trailer being towed.Unique Control Featuresof AS68RC/A465The control unit for this transmission is a separate module or TCM.Dodge mounts its TCM on the steering column; NPR vehicles have theirTCM mounted under the right side ofthe dash.There is a combination O/D andtow/haul button on Dodge trucks: The first time you depress it,6th gear is cancelled and theshifts are delayed. The second time you depress it,5th and 6th gears are cancelled. When you press the buttona third time, all gears areavailable and the shift patternreturns to normal.NPR vehicles only have an O/Dcancel button.This unit uses two temperaturesensors: One is mounted on the lowerpart of the valve body. The TCM usesGEARS December 200811/18/08 8:31:58 AM

The six forwardspeeds and reverseare developed usingfive clutches. Threeclutch assembliesare located in thefront of the unit andtwo clutch packs aremounted in the rearhalf.the valve body temperature sensorto determine when lockup will beallowed, and, under very cold temperatures, it will also disable 5th and6th gears.If the valve body temperature fallsbelow –4ºF, the TCM will only allowreverse and 3rd. When the valve bodytemperature is between 77º – 250ºF, allgears and lockup are allowed.The second temperature sensor ismounted on the cooler outlet line nearthe bellhousing. This sensor monitorsthe temperature of the fluid coming outof the converter — typically the hottestfluid. If this sensor registers temperatures of 284ºF, the TCM applies lockupwhen the engine is above 1200 RPMand disables PTO operation.Some trucks include an optionalexhaust brake system. Under normalconditions the TCM doesn’t interferewith its operation. But under these conditions the TCM will prevent exhaustbraking: If the transmission is downshifting automatically. If the fluid temperature is toohot. If the gear selector is in parkor neutral. During very low speeds.eight pressure switches.To remove the valve body to aircheck the clutches, clean the valvebody, or replace any electrical parts,you must first disconnect all the wiring. If you need to remove more thanone solenoid, you should mark them tomake sure you get them back in theiroriginal locations. (Figures 1 & 2).The TCM has adaptive learn andtorque reduction strategies. When thevehicle is operating normally, the TCMis constantly adjusting the solenoidsto maintain shift quality. With CANcommunication, the TCM also informsthe PCM when engagements and shiftsoccur. The PCM uses this informationto either reduce or increase the idle,and sometimes to reduce engine powerduring shifts.Under certain conditions, such asengine performance problems or driving with codes stored in either the PCMor TCM, the adaptive torque reductionstrategies are disabled. For this reason,after any repairs are completed, codescleared, etc., you must take the systemthrough a relearn procedure.The relearn procedure is performedthrough the DRB scan tool on theDodge vehicles. On NPR vehicles, youcan do it manually, without a scan tool.Contact Bob Sorenson(507) 359-1197orEmailbarefootbob@myclearwave.netThe six forward speeds and reverseare developed using five clutches.Three clutch assemblies are locatedin the front of the unit and two clutchpacks are mounted in the rear half. Tocontrol the five clutch packs, thereare four pressure modulating solenoidsand four on/off solenoids. These are allmounted on the valve body along withGEARS December 200840Dave1208.indd 434311/18/08 8:32:33 AM

What’s Inside the A465 or AS68RC 6-Speed; Part IIThe TCM has adaptivelearn and torquereduction strategies.When the vehicle isoperating normally,the TCM is constantlyadjusting thesolenoids to maintainshift quality.Figure 5: Learning Step 1IMPORTANT: You should perform the relearn after any major workto the transmission. Follow all steps inorder. The vehicle must remain stoppedand the transmission temperature hasto be between 104º – 194ºF. If youskip any steps, the AT overtemp lightwill blink, (Figure 3), and you’ll haveto turn the ignition off and start therelearn procedure over.1. Make sure all accessories —A/C, headlights, etc. — areturned off.2. Set the parking brake.3. Check the fluid level andadjust if necessary.4. Make sure transmission temperature is between 104º –194ºF.5. Start the engine.6. Move shifter from neutral todrive 5 times.7. Connect a jumper wirebetween pins 4 and 11 inthe data link connector. TheCHECK TRANS light shouldstart blinking (on one secondand off two seconds). (Figure4).8. Apply the brake pedal withyour left foot.IMPORTANT: You must keep thebrake pedal applied for therest of this procedure.9. Verify the engine is at idle andthe OD switch is pressed in(OD enabled).10. Move the shifter from drive tomanual 2, three times.Figure 6: Learning Step 2Figure 7: Learning Step 34440Dave1208.indd 44GEARS December 200811/18/08 8:33:05 AM

11. Make sure the CHECKTRANS light flashes on andoff every 0.4 seconds.12. Pull the OD switch out (ODdisabled).13. Verify the CHECK TRANSlight blinks as shown. This isLearning step 1. (Figure 5).14. When the CHECK TRANSlight blinks fast, increase theengine speed to 1000-1500rpm.15. Push the OD switch in (ODenabled). Verify the CHECKTRANS light blinks slowly.16. Wait until the CHECK TRANSlight goes out. Now let theengine rpm return to idle. Thisis Learning step 2. (Figure 6).17. Move the shifter to reverse.18. Pull the OD switch out (ODdisabled). Verify that theCHECK TRANS light blinksas shown. This is Learningstep 3. (Figure 7).19. When the light blinks quickly,increase the engine speed to1000-1500 rpm.20. Push the OD switch in (ODenabled). The CHECK TRANSlight will start to blink slowly.21. When the CHECK TRANSlight starts blinking 1 secondon and 2 seconds off, let theengine return to idle. Usethe following light blinkingpattern to verify this. This isLearning step 4. (Figure 8).22. Place the transmission in parkand release the brake.23. Disconnect the jumper wirefrom the data link connector.24. Turn the ignition off and onagain. Make sure no warninglights are on.Figure 8: Learning Step 4The relearn procedure is done.Shift columns with six speeds they’re in your future, and that futureis now. Sure, these new units seemstrange even intimidating. But so didlockup converters and overdrive transmissions just a few years ago. The trickis to keep reading, and keep learning.GEARS December 200840Dave1208.indd 454511/18/08 8:33:25 AM

DM 3500 Dodge trucks or the Isuzu diesel engine in the NPR trucks. As Randall pointed out, this unit is built for heavy-duty use. The maximum engine torque rating is 730 lb-ft. The stock Cummins 6.7L TD engine is currently rated at 565 lb-ft. The 4-cylinder Isuzu 5.19L engine is rated at 440 lb-ft. CAUTION: Some aftermarket prod-