Engage - atraonline.com

1 GEARS November/December 2007 Man, does this happen a especially on a Friday after-noon when the customer is waiting to pick up his car. And after all is said and done, it usually comes down to something we simply as we go down the list of prob-able causes, keep this in mind: All of these recommendations can and should be checked before or while rebuilding the unit. So with that said, let s get to it. There are a number of areas that can prevent TCC engagement: 1. Low Pressure2. Stuck Converter Regulator Valve3. Stuck Solenoid Regulator Valve4. Stuck Bypass Clutch Control Valve5. Stuck Pressure Failsafe Valve6. Poor Pump Performance7. Worn Pump Shaft or Damaged Pump Shaft Seals8.

2 Pump Shaft Internal Sleeve Loose (Rattles)9. Turbine Shaft Seals Damaged or Missing10. Incorrect Torque Converter Clutch (TCC) Solenoid11. TCC Solenoid Stuck or Electrically Inoperative12. Damaged Internal Wiring Harness13. Incorrect Gear Ratio (Wrong Sprockets)14. Damaged or Worn Stator Support15. Worn Torque Converter Hub Bushing16. Torque Converter Clutch Worn or Damaged17. Worn Bypass Clutch Control Valve Bore18. Worn TCC Regulator Valve Bore Maybe too many things to look at, but it helps to have the right idea before going in. Let s review the diagnostics AX4S/AX4 NTCC Won t Engageby ATRA Technical StaffGEARS November/December 2007 first. The first indi-cation of this prob-lem usually shows up during the test drive before the rebuild; the TCC won t apply.

3 You may not feel it apply after the rebuild either. If you re lucky a code will set: DTC P0741, P1744, or P1728 these codes indicate no TCC apply or a slip-ping you go any further, do yourself a favor: clear the codes. Then put the car on the rack, drive it in all ranges, and use your scan tool to check all of the TCC PIDs:1. TCC = Commanded Duty Cycle for the TCC Solenoid2. TCCMACT = Actual slip across the TCC, measured in RPM3. RPM = Actual engine speed4. TSS_SRC = Actual turbine shaft speed5. TCCRAT = Speed/gear ratio of torque converter/transaxleIf the TCCRAT (TCC Ratio) PID data is incorrect, meaning the RPM doesn t match the TCCRAT 25 RPM, the incorrect transaxle or drive and driv-en sprockets may have been installed.

4 Which means you have a mechani-cal PERIOD! If the code doesn t come back and the TCCRAT is within specs, then you need to check the electrical and hydraulic aspects. Check the easiest first: Did the TCC solenoid get the signal to Engage the TCC? If not, check all of the inputs. Repair any problems that show up, or, if all of the inputs are okay, you re probably going to have to replace the the PCM commands the TCC on but the TCC doesn t Engage , use your scan tool to check the PIDs for a major slip. If you see a slip, try to stall the engine, using your scan tool or by dis-connecting the transmission connector and applying the ranges directly: Hold your foot on the brake and set the parking brake.

5 Command the transmission into third gear. Command the TCC the transmission kills the engine, check the signal strength from the PCM and the solenoid operation. This may still be an internal problem, even though the TCC killed the engine: If you dis-connected the transmission harness, the EPC will be unplugged, so pressures will be well above normal and may overcome whatever was slipping. If you have a TCC signal, but the TCC won t apply, check the resis-tance at the TCC solenoid (figure 1). If you re getting the wrong reading after a rebuild, make sure you used the right TCC solenoid. The new TCC solenoid has a blue connector; the old solenoid is white.

6 Never interchange these sole-noids: some calibrations have problems with the different solenoids that can cause TCC ratio error the engine stumbles or doesn t stall during the test, look for a valve body or sealing problem. Either way, it s time to go into the FailuresOnce the unit is out, pull the side cover and check for wire damage or a faulty solenoid (figure 2). AX4S/AX4 NTCC Won t EngageFigure 2 Figure 1 GEARS November/December 2007 Figure 3 AAX4S/ ax4n TCC Won t Engage There are some common problems that show up in the valve body: Inspect the converter regulator valve, solenoid regulator valve, bypass clutch control valve and pressure failsafe valve and their bores (figure 3a, 3b).

7 COrrectionCauseCOMPLAINTThe cast-aluminum sleeve breaks atthe retaining pin area due to sleeveporosity. Pieces of the broken sleevecan prevent proper valve billet aluminum sleeve provideshigher tensile strength and reducedporosity to resist breakage. Theredesigned retainer and end plug provide better holding Valve & SleeveAssembly94987-01K1 Sleeve1 Valve1 End Plug1 Coiled Spring Pin1 SpringCut back on stressWhen the cast-aluminum cutback valve sleeve breaks at the retaining pinarea, the valve and sleeve move out of position, which can create engine stallswhen the vehicle is placed into gear. Breakage also allows the lockup controlvalve to move out of position, which can create multiple and/or intermittentconverter apply issues.

8 Broken pieces of the sleeve can end up in the pan,and smaller pieces can clog filters or lodge in other moving components. TheSonnax billet aluminum cutback sleeve is made from material that has highertensile strength and reduced porosity to resist breakage. The redesigned retain-er and end plug provide better holding capacity and eliminate stress points thatlead to breakage. Improved valve and sleeve materials also prevent wear andprovide better sealing capacity through temperature changes. With all of theparts included with this kit, the repair procedure is a simple drop-in solution. Engine stalls when put in gearSECONDARY COMPLAINT Converter apply complaints Broken sleeve creates debrisThe new Sonnax Cutback Valve & Sleeve Assembly for the AW 450-43 LEbeats the OEM with stronger materials to eliminate stress points that lead to Drive, Box 440 Bellows Falls, VT 05101-0440 USA800-843-2600 802-463-9722 F: 2007 Sonnax Industries, I M E T E S T E D I N D U S T R Y T R U S T E more informationabout all our products and tools, and tolocate a Sonnax Transmission Specialties distributor near BodyAW 450-43 LESleeveSpringValveEndPlugCoiled Spring 10/30/07 3.

9 52 PM Page 1 GEARS November/December 2007 Figure 3 BAX4S/ ax4n TCC Won t Engage There are some common problems that show up in the valve body: Inspect the converter regulator valve, solenoid regulator valve, bypass clutch control valve and pressure failsafe valve and their bores (figure 3a, 3b).As a dedicated transmission professional Rick Basta, owner of Transmission Kings, knows the secret to a successful shop is dependable performance and satisfied customers. That s why he rebuilds with TransTec . No surprises. Buy a TransTec kit and you can bet the bank that all the parts required for the job are there and that they all fit. It s no accident; our engineering department, product development and technical staffs, plus a proven QA system, combine to give you the assurance you can t get anywhere else.

10 Manufactured to meet the strictest OE standards, TransTec kits contribute to a faster rebuild with virtually no comebacks. And detailed technical inserts reinforce what the technicians learn at various seminars. These are just a few reasons why transmis-sion rebuilders request the kit in the gold and black bag . TransTec kits are produced by Freuden-berg-NOK , the American partnership with more than $6 billion in resources. Yet it is the close, personal support that impresses transmission shops like Rick s. TransTec makes it Basta, Owner of Transmission KingsCleveland, OH MY GUYS ALWAYS REQUEST TRANSTEC . ORIGINALThe Aftermarket Business of Freudenberg-NOK4 s & s WWW 4 RANS4EC COM s -ILAN /( New TransTec ad 110/24/07 4:58:32 PM10 GEARS November/December 2007 Check for pump shaft wear or damaged seals.)