Hi! workshop manual,service manual,repair manual [Sign in] [register]

HYUNDAI WHEEL LOADER HL730TM-3 TROUBLESHOOTING GUIDE

TRANSMISSION
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 :

1.TRANSMISSION

1).Problem : Transmission slippage

Cause: Low oil level. Wrong oil grade. Restricted transmission pump suction screen. Leak in transmission control valve or gasket. Low transmission pump flow due to worn pump. Weak or broken press

Remedy: Add oil. Change oil. Remove and clean screen. Remove valve and inspect gaskets. Do transmission pump flow test. Do transmission system pressure test.

2).Problem : Error code on display

Cause: Something wrong in transmission.

Remedy: Go to transmission error code group at page 3-17~3-19.

3).Problem : Error code on display

Cause: Something wrong in transmission.

Remedy: Go to transmission error code group at page 3-17~3-19.

4).Problem :  Machine will not move

Cause:  Low oil level. Applied park brake. No power to transmission controller. Malfunctioning parking brake solenoid valve. Restricted orifice of PPC valve. Excessive leakage in transmission element. Worn clutch disks. Low or no transmission pressure. Service brake will not release. Failed torque converter. Broken shafts or gears. Broken drive shafts. Broken ring or pinion gear.

Remedy: Add oil. Check parking brake fuse. Check continuity to parking brake switch. Check transmission controller fuse. Remove and inspect parking brake solenoid valve. Check for power to solenoid valve. Remove orifice and check for contamination and/or plugging. (Do not remove valve housing for this purpose.) Do transmission element leakage test using system pressure. Repair transmission. See transmission pressure is low in this group. Do brake pedal operational check. Do service and park system drag checks. Do torque converter stall test. If engine pulldown in normal, torque converter is good. Drain transmission to determine if large pieces of metal contamination are present. Inspect drive shafts and universal joints for external damage. Repair. If drive shaft rotate with transmission in gear but machine does not move, a differential failure is indicated. Repair.

5).Problem :  Machine does not engage in low gear

Cause: Malfunctioning transmission control solenoid valve. Stuck spool in transmission control valve. Stuck PPC valve. Malfunctioning transmission speed sensor.

Remedy: Check solenoid valve. Remove and inspect transmission control valve spools. Remove end cover to inspect PPC valve. Replace if necessary. Check speed sensor

6).Problem :Transmission pressure is low(All gears)

Cause: Low oil level. Failed transmission pressure switch. Plugged suction strainer. Stuck transmission pressure regulating valve or broken spring. Failed control valve gasket. Stuck PPC valve.

Remedy: Check transmission oil level and refill if necessary. Verify transmission system pressure. Do transmission system pressure test. Transmission pump may be noisy if transmission suction screen is clogged. Drain transmission. Remove and clean suction screen. Also, check condition of transmission filter. Remove transmission pressure regulating valve. Inspect for damage(See transmission control valve). Inspect transmission control valve for external leakage. Remove control valve. Inspect or replace gasket. Remove end cover to inspect modulation spool and check torque on cap

7).Problem : Transmission system pressure is low(One or two gears)

Cause: Failed transmission pump. Failed transmission control valve gasket. Leakage in clutch piston or seal ring.

Remedy: Do pump flow test. Inspect transmission control valve for external leakage. Remove control valve. Inspect or replace gasket. Disassemble and repair.

8).Problem : Transmission shifts too low

Cause: Low oil level(Aeration of oil). Low transmission pressure. Restricted transmission pump suction screen. Low transmission pump flow. Excessive transmission element leakage. Stuck PPC valve. Restricted PPC valve orifice. Restricted oil passages between control valve and transmission elements. Incorrect transmission oil

Remedy: Add oil. Do transmission system pressure test. Remove and clean screen. Do transmission pump flow test. Do transmission element leakage test using system pressure. Remove end cover to inspect modulation spool. Replace if necessary. Remove orifice and inspect for contamination and /or plugging. Remove control valve and inspect oil passage. Change oil(DEXRON єor DEXRON ѕ)

9).Problem : Error code on display

Cause: Something wrong in transmission.

Remedy: Go to transmission error code group at page 3-17~3-19.

10).Problem :Transmission shifts too fast

Cause: Wrong transmission controller. System pressure too high. Stuck PPC valve. Stuck or missing check valves. Missing O-ring from end of modulation orifice. Broken piston return spring. Incorrect transmission oil

Remedy: Check if transmission controller has been changed Do transmission system pressure test. Remove and inspect PPC valve. Replace if necessary. Also remove end cover to inspect PPC valve and control valve housing. Replace if necessary. Inspect transmission control valve. Remove orifice and inspect port for O-ring. Disassemble and inspect clutch. Change oil(DEXRON єor DEXRON ѕ)

11).Problem : Machine “creeps” in neutral

Cause: Warped disks and plates in transmission.

Remedy: Check transmission.

12).Problem : Transmission hydraulic system overheats

Cause: High oil level. Low oil level. Wrong oil grade. Park brake dragging. Pinched, restricted or leaking lube lines. Machine operated in too high gear range. Malfunction in temperature gauge or sensor. Restricted air flow through oil cooler or radiator. Failed oil cooler bypass valve(In thermal bypass valve). Failed thermal bypass valve. Internally restricted oil cooler. Leakage in transmission hydraulic system. Malfunction in converter relief valve. Low transmission pump output

Remedy: Transmission overfilled or hydraulic pump seal leaking. Add oil. Change oil. Check for heat in park brake area. Check cooler lines. Operate machine in correct gear range. Install temperature sensor the verify temperature. Do tachometer/temperature reader installation procedure. Do radiator air flow test. Disassemble and inspect. Remove thermal bypass valve and check to see if machine still overheats. Do transmission oil cooler thermal bypass valve test. Do oil cooler restriction test. Do transmission system pressure, element leakage test. Do converter out pressure test. Do transmission pump flow test.

13).Problem : Excessive transmission noise(Under load or no load)

Cause: Too low engine low idle. Worn parts or damaged in transmission. Warped drive line between engine and torque converter. Low or no lube.

Remedy: Check engine low idle speed. Remove transmission suction screen. Inspect for metal particles. Repair as necessary. Inspect drive line. Do converter-out and lube pressure test. Do transmission pump flow test.

14).Problem : Foaming oil

Cause: Incorrect type of oil. High oil level. Low oil level. Air leak on suction side of pump.

Remedy: Change oil. Transmission overfilled or hydraulic pump seal leaking. Add oil. Check oil pickup tube on side of transmission.

15.).Problem : Machine lacks power and acceleration

Cause: Engine high idle speed set too low. Incorrect transmission oil. Aerated oil. Low transmission pressure. Warped transmission clutch. Torn transmission control valve gasket. Brake drag. Failed torque converter. Low engine power.

Remedy: Check high idle adjustment. Change oil. Add oil. Do transmission system pressure test. Do transmission clutch drag checks. Inspect gasket. Do brake drag check. Do torque converter stall speed test. Do engine power test.

16).Problem : Machine vibrates

Cause: Aerated oil. Low engine speed. Failed universal joints on transmission drive shaft or differential drive shafts.

Remedy: Add oil. Check engine speed. Check universal joints

17.).Problem :Torque converter stall RPM too high

Cause: Aerated oil. Stuck open converter relief valve. Leakage in torque converter seal. Torque converter not transferring power(Bent fins, broken starter).

Remedy: Put clear hose on thermal bypass outlet port. Run machine to check for bubbles in oil. Do converter-out pressure test. Do converter-out pressure test. Replace torque converter

18).Problem : Torque converter stall RPM too low

Cause: Low engine power. Mechanical malfunction.

Remedy: Do engine power test. Remove and inspect torque converter.

19).Problem :Transmission pressure light comes ON when shifting from forward to reverse(All other gears OK)

Cause: Low oil level. Cold oil. Leak in reverse pack.

Remedy: Add oil. Warm oil to specification. Do transmission pressure, pump flow, and leakage check.

20).Problem : Transmission pressure light comes ON for each shift

Cause: Cold oil. No time delay in monitor. Restriction in modulation orifice. Stuck PPC valve. Low transmission pressure circuit. Leak in transmission pressure circuit. Failed transmission pump. Clogged filter

Remedy: Warm oil to specification. Do monitor check. Remove orifice and inspect for restriction and/or plugging. Remove and inspect. Do transmission system pressure test. Do converter out pressure test. Do transmission pump flow test. Inspect filter. Replace.

2.DIFFERENTIAL / AXLE

1).Problem : Differential low on oil

Cause: External leakage.

Remedy: Inspect axle and differential for leaks.

2).Problem : Excessive differential and/or axle noise

Cause: Low oil level in differential. Incorrect type of oil. Dragging brakes. Failed pinion bearing. Incorrect gear mesh pattern between ring and pinion gear. Failed differential pinion gears and/or cross shafts. Failed axle bearing. Mechanical failure in axle planetary.

Remedy: Check oil. Remove drain plug and inspect for metal particles in differential case. Disassemble and determine cause. Change oil Do brake check. Remove and inspect pinion. Check to ensure pinion housing was indexed. Remove pinion gear housing and inspect ring and pinion gear. Remove differential housing drain plug and inspect for metal particles. Disassemble and inspect. Do axle bearing adjustment check. Remove differential. Inspect, repair.

3).Problem : Oil seeping

Cause: Excessive end play in axle. Worn outer bearing and/or cup. Overfilled differential.

Remedy: Do axle bearing adjustment check. Disassemble and inspect outer axle bearing, cup, spacer, and seal. Replace, if necessary. Check differential oil return system for excessive internal restriction.

4).Problem : Axle overheats

Cause: Low differential oil. Overfilled differential. Brake drag.

Remedy: Add oil. See differential overfills with oil in this group. See brakes drag in this group.

3. DRIVE LINE

1).Problem : Excessive drive line vibration or noise

Cause: Yokes not in line on drive shafts. Worn front drive line support bearing. Bent drive shaft. Loose yoke retaining nuts(Drive shafts wobble at high speed). Rear axle oscillating support. Lack of lubrication

Remedy: Inspect. Align drive shaft yokes. Inspect, repair. Inspect all drive shafts. Replace. Inspect. Replace. Inspect, repair. Lubricate with proper grade of grease.

Related files:

468

Submit a Comment

Your email address will not be published.


*

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>