GROUP 2 OPERATIONAL CHECKS AND TROUBLESHOOTING

GROUP OPERATIONAL CHECKS AND TROUBLESHOOTING POWER TRAIN OPERATIONAL CHECKS This procedure is designed so that the mechanic can make a quick check of the system using a minimum amount of diagnostic equipment If you need additional information, read Structure and function, Group A location will be required which is level and has adequate space to complete the checks The engine and all other major components must be at operating temperature for some checks Locate system check in the left column and read completely, following the sequence from left to right Read each check completely before performing At the end of each check, if no problem is found(OK), that check is complete or an additional check is needed If problem is indicated(NOT OK), you will be given repair required and group location If verification is needed, you will be given next best source of information : Chapter : Troubleshooting Group : Tests and adjustments 3-29 Ɠ Transmission oil must be at operating temperature for these checks Item Description Service action Start engine Apply service OK brakes and release parking brake Check completed Transmission oil warmup procedure Move gear selector lever to 3rd speed TRANS Move gear selector lever to forward "F" position Increase engine speed to high idle for 30 seconds Move gear selector lever to neutral "N" position and run for 15 seconds Repeat procedure until transmission temperature gauge arrow points to bar above dial Move gear selector lever to each OK position Check completed Gear selector lever and neutral lock latch checks Engine OFF NOTE : Gear selector lever NOT OK position changes slightly as Repair lock or replace steering column is tilted switch FEEL : Lever must move freely through all positions ND Engage neutral lock Apply slight effort to move lever into forward(F) and reverse(R) LOOK : Neutral lock must stay engaged Transmission noise check Engine running Run engine at approximately OK 1700rpm Check completed Drive unit with transmission in NOT OK each forward and reverse speed Go to transmission makes excessive noise group LISTEN : Transmission must not make excessive noise in any range Engine rpm must not "lug down" as unit is shifted between gears 3-30 Item Description Service action Release parking brake and shift to OK 2nd forward Check completed Transmission "quick shift" check Engine running Drive machine at approximately NOT OK 5km/h and press gear selector Check connector at base lever kick down switch or RCV of control valve lever switch once IF OK LOOK/FEEL : Transmission must Go to transmission shift to and remain in 1st gear controller circuit in group Press gear selector lever kick down switch once A LOOK/FEEL : Transmission must shift back to 2nd gear Shift to (3rd or 4th) gear and press gear selector lever kick down switch once LOOK/FEEL : Transmission must not shift down Forward, reverse and 4th speed clutch pack drag check Ɠ Transmission must be warmed up for this check Engine running Park unit on level surface Apply service brakes OK Check completed NOT OK Move gear selector lever to If unit moves, repair neutral transmission Move gear selector lever to 1st Release parking brake and service brakes Run engine at low idle LOOK : Unit must not move in either direction NOTE : If unit moves forward, either the forward pack or the 4th speed pack is dragging 3-31 Item Transmission pressure, pump flow, and leakage check Engine running Description Run engine at low idle Release parking brake Service action OK Check completed NOT OK Shift transmission to reverse, then Do transmission leakage forward, and then to 1st, 2nd, and test, system pressure test, 3rd speeds or pump flow test in group Wait seconds after each shift and observe transmission pressure indicator light LOOK : Indicator light must not come on NOTE : If light comes on in one gear only, leakage is indicated on that gear If light comes on in all gears, low pump flow or pressure is indicated Transmission shift modulation check Engine running Run engine at approximately OK 1700rpm Check completed Put transmission in 1st forward, NOT OK shift several times from forward to Go to unit shifts too fast, reverse and reverse to forward chapter in this group Repeat check in 2nd gear LOOK : Unit must slow down and change direction smoothly Torque converter check Start engine Apply service OK brakes and release parking brake Check completed Move gear selector lever to 4th NOT OK speed If stall rpm are too low or too high, problem may be Move gear selector control lever engine power or torque to forward "F" position converter Increase engine speed to high IF OK idle Replace transmission LOOK : Torque converter stall torque converter rpm must be within the following range Stall rpm : 2250 ~ 2350rpm Move gear selector control lever to neutral "N" position and run for 15 seconds 3-32 TROUBLESHOOTING 1) TRANSMISSION Ɠ Diagnose malfunction charts are arranged from most probable and simplest to verify, to least likely, more difficult to verify Remember the following steps when troubleshooting a problem : Step Operational check out procedure(See group in section 1.) Step Operational checks(In this group.) Step Troubleshooting Step Tests and/or adjustments(See group 3.) Problem Transmission slippage Cause Remedy Low oil level Add oil Wrong oil grade Change oil Restricted transmission pump Remove and clean screen suction screen Leak in transmission control Remove valve and inspect gaskets valve or gasket Low transmission pump flow Do transmission pump flow test due to worn pump Weak or broken pressure Do transmission system pressure test regulating valve spring 3-33 Problem Machine will not move Cause Remedy Low oil level Add oil Applied park brake Check parking brake fuse Check continuity to parking brake switch No power to transmission Check transmission controller fuse controller Malfunctioning parking brake Remove and inspect parking brake solenoid solenoid valve valve Check for power to solenoid valve Restricted orifice of modulation Remove orifice and check for contamination valve and/or plugging (Do not remove valve housing for this purpose.) Machine does not engage in low gear Excessive leakage in transmission element Do transmission element leakage test using system pressure Worn clutch disks Repair transmission Low or no transmission pressure See transmission pressure is low in this group Service brake will not release Do brake pedal operational check Do service and park system drag checks Failed torque converter Do torque converter stall test If engine pulldown in normal, torque converter is good Broken shafts or gears Drain transmission to determine if large pieces of metal contamination are present Broken drive shafts Inspect drive shafts and universal joints for external damage Repair Broken ring or pinion gear If drive shaft rotate with transmission in gear but machine does not move, a differential failure is indicated Repair Malfunctioning transmission Check solenoid valve control solenoid valve Stuck spool in transmission Remove and inspect transmission control valve control valve spools Stuck modulation valve Remove end cover to inspect modulation valve Replace if necessary Malfunctioning transmission Check speed sensor speed sensor 3-34 Problem Cause Remedy Transmission pressure Low oil level is low(All gears) Check transmission oil level and refill if necessary Failed transmission pressure Verify transmission system pressure Do switch transmission system pressure test Plugged suction strainer Transmission pump may be noisy if transmission suction screen is clogged Drain transmission Remove and clean suction screen Also, check condition of transmission filter Stuck transmission pressure Remove transmission pressure regulating valve regulating valve or broken Inspect for damage(See transmission control valve) spring Failed control valve gasket Inspect transmission control valve for external leakage Remove control valve Inspect or replace gasket Stuck modulation valve Remove end cover to inspect modulation spool and check torque on cap screws retaining control valve to transmission Transmission system Failed transmission pump Do pump flow test pressure is low (One or Failed transmission control Inspect transmission control valve for external two gears) leakage Remove control valve valve gasket Inspect or replace gasket Leakage in clutch piston or seal Disassemble and repair ring Transmission shifts too Low oil level(Aeration of oil) low Low transmission pressure Add oil Do transmission system pressure test Restricted transmission pump Remove and clean screen suction screen Low transmission pump flow Do transmission pump flow test Excessive transmission element leakage Do transmission element leakage test using system pressure Stuck modulation valve Remove end cover to inspect modulation spool Replace if necessary Restricted modulation valve Remove orifice and inspect for contamination and /or plugging orifice Restricted oil passages Remove control valve and inspect oil passage between control valve and transmission elements Incorrect transmission oil 3-35 Change oil Problem Cause Remedy Transmission shifts too Wrong transmission controller fast Check if transmission controller has been changed System pressure too high Do transmission system pressure test Stuck modulation valve Remove and inspect modulation valve Replace if necessary Also remove end cover to inspect modulation valve and control valve housing Replace if necessary Stuck or missing check valves Inspect transmission control valve Missing O-ring from end of Remove orifice and inspect port for O-ring modulation orifice Machine "creeps" in neutral Broken piston return spring Disassemble and inspect clutch Incorrect transmission oil Change oil Warped disks and plates in Check transmission transmission Transmission hydraulic High oil level system overheats Transmission overfilled or hydraulic pump seal leaking Low oil level Add oil Wrong oil grade Change oil Park brake dragging Check for heat in park brake area Pinched, restricted or leaking Check cooler lines lube lines Machine operated in too high Operate machine in correct gear range gear range Malfunction in temperature Install temperature sensor the verify temperature gauge or sensor Do tachometer/temperature reader installation procedure Restricted air flow through oil Do radiator air flow test cooler or radiator Failed oil cooler bypass Disassemble and inspect valve(In thermal bypass valve) Failed thermal bypass valve Remove thermal bypass valve and check to see if machine still overheats Do transmission oil cooler thermal bypass valve test Internally restricted oil cooler Do oil cooler restriction test Leakage in transmission Do transmission system pressure, element hydraulic system leakage test Malfunction in converter relief Do converter out pressure test valve Low transmission pump output Do transmission pump flow test 3-36 Problem Cause Remedy Excessive transmission Too low engine low idle Check engine low idle speed noise(Under load or no Worn parts or damaged in Remove transmission suction screen load) for metal particles transmission Repair as necessary Inspect Warped drive line between Inspect drive line engine and torque converter Foaming oil Low or no lube Do converter-out and lube pressure test transmission pump flow test Do Incorrect type of oil Change oil High oil level Transmission overfilled or hydraulic pump seal leaking Low oil level Add oil Air leak on suction side of Check oil pickup tube on side of transmission pump Oil ejected from dipstick Plugged breather Inspect breather on top of transmission Replace Machine vibrates Aerated oil Add oil Low engine speed Check engine speed Failed universal joints on Check universal joints transmission drive shaft or differential drive shafts Machine lacks power Engine high idle speed set too Check high idle adjustment and acceleration low Incorrect transmission oil Change oil Aerated oil Add oil Low transmission pressure Do transmission system pressure test Warped transmission clutch Do transmission clutch drag checks Torn transmission control valve Inspect gasket gasket Brake drag Do brake drag check Failed torque converter Do torque converter stall speed test Low engine power Do engine power test Put clear hose on thermal bypass outlet port Run machine to check for bubbles in oil Torque converter stall Aerated oil RPM too high Stuck open converter relief Do converter-out pressure test valve Leakage in torque converter Do converter-out pressure test seal Replace torque converter Torque converter not transferring power(Bent fins, broken starter) 3-37 Problem Cause Remedy Torque converter stall Low engine power RPM too low Mechanical malfunction Do engine power test Transmission pressure Low oil level light comes ON when Cold oil shifting from forward to reverse(All other gears Leak in reverse pack OK) Add oil Remove and inspect torque converter Warm oil to specification Do transmission pressure, pump flow, and leakage check Transmission pressure Cold oil Warm oil to specification light comes ON for each No time delay in monitor Do monitor check shift Restriction in modulation orifice Remove orifice and inspect for restriction and/or plugging Stuck modulation valve Remove and inspect Low transmission pressure Do transmission system pressure test circuit Leak in transmission pressure Do converter out pressure test circuit Failed transmission pump Do transmission pump flow test Clogged filter Inspect filter Replace 3-38 2) DIFFERENTIAL / AXLE Problem Insufficient braking Cause Remedy Incorrect adjustment Inspect disc thickness and if discs are usable readjust brakes to the specifications in page 3127 Brake discs worn out Inspect disc thickness and replace if necessary Incorrect brake fluid Replace all seals in axle that have made contact with the incorrect fluid and all brake hoses If incorrect fluid leaked into axle oil, seals and Orings in axle must be replaced Loss of brake fluid Inspect for and repair any leaks in outside circuit If caused by incorrect brake fluid see correction No.3 If leak is to the outside replace the O-rings between the center and intermediate housings If leak is to the inside replace above O-rings and brake piston O-rings Overheated axle causing See Overheating problem brake fluid to vaporize (Brake return when axle cools) Soft brake pedal Air in brake circuit Bleed brakes as described in page 4-30 Overheating Oil level wrong Drain, flush and refill oil to proper level Too small of a brake gap Readjust brakes to the specifications in page 3127 Incorrect brake fluid in system See correction No.3 10 Restriction in brake lines Inspect for and replace damage lines 11 Restriction in return line of Inspect for and replace damaged return line Inspect for and remove any filter, tee'd in line or brake Servo system any other source of back pressure from the return line Diff-lock inoperative 12 Incorrect lubricant Change the retaining rings of the brake circuit and brake pump 13 Worn discs Replace discs Oil coming out of 14 Leak in internal brake See correction No.2 and breather system NoSpin indexing noise 15 Unequal tire pressure left when driving straight and right ƓWith NoSpin, fatigue 16 Different style, size or brand damage can occure on of tires between left and right the side with the larger tire hand side Inflate tires to the recommended pressure, or until the rolling radius is equal Noise during coast and 17 Wheel bearings damaged under power the same Replace and adjust 3-39 Change tires to make the rolling radius equal Vary the tire pressure within the specifications until the rolling radius is equal Problem Cause Remedy Noise under power 18 Low oil level greater than during 19 Incorrect lubricant coast 20 Ring and pinion worn Refill oil to proper level See correction No.12 Inspect through top cover Replace and adjust 21 Worn ring and pinion Replace and adjust bearings 22 Worn planetary gears or Replace bearings Noise during coast 23 Loose pinion nut greater than under power 24 Only pinion damaged Noise during turn (Without Nospin) Inspect ring, pinion and pinion bearings If undamaged, retighten nut bearing See correction No.21 25 Worn spider and/or side Replace gears 26 Worn or cardanshaft damaged Inspect and replace 27 Loose wheel Inspect for wheel and wheel stud damage Replace if needed and retorque lugnuts 3) DRIVE LINE Problem Cause Remedy Excessive drive line Yokes not in line on drive Inspect Align drive shaft yokes shafts vibration or noise Worn front drive line support Inspect, repair bearing Bent drive shaft Inspect all drive shafts Replace Loose yoke retaining nuts(Drive Inspect Replace shafts wobble at high speed) Rear axle oscillating support Inspect, repair Lack of lubrication Lubricate with proper grade of grease 3-40 ... lubricant coast 20 Ring and pinion worn Refill oil to proper level See correction No. 12 Inspect through top cover Replace and adjust 21 Worn ring and pinion Replace and adjust bearings 22 Worn planetary... correction No .21 25 Worn spider and/ or side Replace gears 26 Worn or cardanshaft damaged Inspect and replace 27 Loose wheel Inspect for wheel and wheel stud damage Replace if needed and retorque... must be within the following range Stall rpm : 22 50 ~ 23 50rpm Move gear selector control lever to neutral "N" position and run for 15 seconds 3- 32 TROUBLESHOOTING 1) TRANSMISSION Ɠ Diagnose malfunction