dallasmef
Active Member
- Joined
- July 9, 2008
- Messages
- 51
- Reaction score
- 0
- City, State
- Dallas, TX
- Year, Model & Trim Level
- 1997 Explorer XLT
Transmission Slippage
Problem Solution
Low fluid level Check and add fluid
Wrong fluid grade Check oil fluid
Loose drum bands, or Broken Check tension and tighten or replace as needed
Transmission pump suction restricted Remove and clean screen/filter
Faulty shift sensors Replace solenoids and related shift sensors
Transmission control valve body gasket leakage Remove valve body and inspect gaskets
Weak or broken pressure regulating valve spring Do Transmission System Pressure Test
Low transmission pump flow due to worn pump Do Transmission Pump Flow Test
Clutch cut-off valve sticking Remove and inspect clutch cut-off valve
Restricted modulation orifice housing orifices Remove control valve housing and check for restrictions in valve and valve
Excessive transmission element leakage Do Transmission Element Leakage Test Using System Pressure
Worn clutch disks/plates Replace clutch disks/plates
Unit Will Not Move
Problem Solution
Low or no transmission pressure See Transmission Pressure is low (all gears) or Transmission Pressure is low (one or two gears)
Service brakes will not release Do Brake Pedal Operational Check. Do Service and Park Brake System Drag Checks
Park brake applied or parkswitch misadjusted Adjust park brake switch
Stuck control valve spool Check shift linkage operation. Disconnect shift linkage from control valve spool and check linkage movement.
Failed torque converter Do Torque Converter Stall Test. If engine pulldown is 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 shafts rotate with transmission in gear but unit does not move, a differential failure is indicated. Repair
Transmission Pressure Is Low (All Gears)
Problem Solution
Low oil level Check transmission oil level and refill if necessary
Switch failure Verify transmission system pressure. Do Transmission System Pressure Test
Suction strainer is plugged Transmission pump may be noisy if transmission suction screen is clogged. Drain transmission. Remove and clean suction screen. Also, check condition of transmission filter.
Transmission pressure regulating valve is stuck or spring is broken Remove transmission pressure regulating valve. Inspect for damage
Control valve gasket failure Inspect transmission control valve for external leakage. Remove control valve. Inspect or replace gasket.
Transmission pump is failed Do pump flow test
Transmission System Pressure Is Low (One or Two Gears)
Problem Solution
Failed transmission control valve gasket Inspect transmission control valve for external leakage. Remove control valve. Inspect or replace gasket.
Clutch piston or seal ring leakage Disassemble and repair
Transmission Shifts Too Slow
Problem Solution
Low oil level (aeration of oil) Check and add oil
Low transmission pressure Do Transmission System Pressure Test
Transmission pump suction screen restricted Remove and clean screen
Low transmission pump flow Do Transmission Pump Flow Test
Excessive transmission element leakage Do Transmission Element Leakage Test Using System Pressure
Oil passages restricted between control valve body and transmission elements Remove control valve body and inspect oil passages
Clutch cut-off valve sticking Remove and inspect cut-off valve
Transmission Shifts Too Fast
Problem Solution
System pressure too high Do Transmission System Pressure Test
Stuck modulation valve Remove and inspect modulation valve
Stuck or missing forward/reverse check valve Inspect transmission control valve body
Broken piston return spring Disassemble and inspect clutch
Unit "Creeps" in Neutral
Problem Solution
Warped disks and plates in transmission Check transmission
Transmission Hydraulic System Overheats
Problem Solution
High oil level Check and adjust
Low oil level Check and correct
Wrong oil grade Check oil grade
Lube lines pinched, restricted, or leaking Check cooler lines
Unit operated in too high gear range Operate unit in correct gear range
Temperature gauge or sender malfunction Install temperature sensor to verify temperature. Do Tachometer/Temperature Reader Installation Procedure.
Air flow through oil cooler or radiator restricted Do Radiator Air Flow Test
Oil cooler thermal relief bypass valve stuck Bypass thermal bypass valve and check to see if unit still overheats. Do Transmission Oil Cooler Thermal Bypass Valve Test
Oil cooler internally restricted Do Oil Cooler Restriction Test
Warped disks and plates in transmission Do Transmission Clutch Drag Check
Leakage in transmission hydraulic system Do Converter-Out Pressure Test. Do Transmission Element Leakage Test
Low transmission pump output Do Transmission Pump Flow Test
Excessive Transmission Noise (under load or no load)
Problem Solution
Engine slow idle too low Check engine slow idle speed
Parts worn or damaged in transmission Remove transmission suction screen. Inspect for metal particles. Repair as necessary
Low or no lube Do Converter-Out and Lube Pressure Test. Do Transmission Pump Flow Test
Incorrect type of oil Change oil
High oil level Drain some oil
Low oil level Add oil
Air leak on suction side of pump Check oil pickup tube on side of transmission
Unit Vibrates
Problem Solution
Aerated oil Check and add oil
Failed universal joints on transmission drive shaft or differential drive shafts Check universal joints
Unit Lacks Power And Acceleration
Problem Solution
Engine fast idle speed set too low Check fast idle adjustment
Incorrect transmission oil Check oil
Aerated oil Check and add oil
Low transmission pressure Do Transmission System Pressure Test.
Warped transmission clutch Do Transmission Clutch Drag Checks
Brake drag Do Brake Drag Check
Clutch cut-off valve sticking Remove and inspect clutch cut-off valve
Low engine power Do Engine Power Test
Torque Converter Stall RPM Too High
Problem Solution
Aerated oil Put clear hose on thermal bypass outlet port. Run unit to check for bubbles in oil
Converter relief valve stuck open Do Converter-Out Pressure Test
Torque converter seal leakage Do Converter-Out Pressure Test
Torque converter not transferring power (bent fins, broken stator) Remove and inspect torque converter
Torque Converter Stall RPM Too Low
Problem Solution Low engine power Do Engine Power Test
Mechanical malfunction Remove and inspect torque converter
Problem Solution
Low fluid level Check and add fluid
Wrong fluid grade Check oil fluid
Loose drum bands, or Broken Check tension and tighten or replace as needed
Transmission pump suction restricted Remove and clean screen/filter
Faulty shift sensors Replace solenoids and related shift sensors
Transmission control valve body gasket leakage Remove valve body and inspect gaskets
Weak or broken pressure regulating valve spring Do Transmission System Pressure Test
Low transmission pump flow due to worn pump Do Transmission Pump Flow Test
Clutch cut-off valve sticking Remove and inspect clutch cut-off valve
Restricted modulation orifice housing orifices Remove control valve housing and check for restrictions in valve and valve
Excessive transmission element leakage Do Transmission Element Leakage Test Using System Pressure
Worn clutch disks/plates Replace clutch disks/plates
Unit Will Not Move
Problem Solution
Low or no transmission pressure See Transmission Pressure is low (all gears) or Transmission Pressure is low (one or two gears)
Service brakes will not release Do Brake Pedal Operational Check. Do Service and Park Brake System Drag Checks
Park brake applied or parkswitch misadjusted Adjust park brake switch
Stuck control valve spool Check shift linkage operation. Disconnect shift linkage from control valve spool and check linkage movement.
Failed torque converter Do Torque Converter Stall Test. If engine pulldown is 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 shafts rotate with transmission in gear but unit does not move, a differential failure is indicated. Repair
Transmission Pressure Is Low (All Gears)
Problem Solution
Low oil level Check transmission oil level and refill if necessary
Switch failure Verify transmission system pressure. Do Transmission System Pressure Test
Suction strainer is plugged Transmission pump may be noisy if transmission suction screen is clogged. Drain transmission. Remove and clean suction screen. Also, check condition of transmission filter.
Transmission pressure regulating valve is stuck or spring is broken Remove transmission pressure regulating valve. Inspect for damage
Control valve gasket failure Inspect transmission control valve for external leakage. Remove control valve. Inspect or replace gasket.
Transmission pump is failed Do pump flow test
Transmission System Pressure Is Low (One or Two Gears)
Problem Solution
Failed transmission control valve gasket Inspect transmission control valve for external leakage. Remove control valve. Inspect or replace gasket.
Clutch piston or seal ring leakage Disassemble and repair
Transmission Shifts Too Slow
Problem Solution
Low oil level (aeration of oil) Check and add oil
Low transmission pressure Do Transmission System Pressure Test
Transmission pump suction screen restricted Remove and clean screen
Low transmission pump flow Do Transmission Pump Flow Test
Excessive transmission element leakage Do Transmission Element Leakage Test Using System Pressure
Oil passages restricted between control valve body and transmission elements Remove control valve body and inspect oil passages
Clutch cut-off valve sticking Remove and inspect cut-off valve
Transmission Shifts Too Fast
Problem Solution
System pressure too high Do Transmission System Pressure Test
Stuck modulation valve Remove and inspect modulation valve
Stuck or missing forward/reverse check valve Inspect transmission control valve body
Broken piston return spring Disassemble and inspect clutch
Unit "Creeps" in Neutral
Problem Solution
Warped disks and plates in transmission Check transmission
Transmission Hydraulic System Overheats
Problem Solution
High oil level Check and adjust
Low oil level Check and correct
Wrong oil grade Check oil grade
Lube lines pinched, restricted, or leaking Check cooler lines
Unit operated in too high gear range Operate unit in correct gear range
Temperature gauge or sender malfunction Install temperature sensor to verify temperature. Do Tachometer/Temperature Reader Installation Procedure.
Air flow through oil cooler or radiator restricted Do Radiator Air Flow Test
Oil cooler thermal relief bypass valve stuck Bypass thermal bypass valve and check to see if unit still overheats. Do Transmission Oil Cooler Thermal Bypass Valve Test
Oil cooler internally restricted Do Oil Cooler Restriction Test
Warped disks and plates in transmission Do Transmission Clutch Drag Check
Leakage in transmission hydraulic system Do Converter-Out Pressure Test. Do Transmission Element Leakage Test
Low transmission pump output Do Transmission Pump Flow Test
Excessive Transmission Noise (under load or no load)
Problem Solution
Engine slow idle too low Check engine slow idle speed
Parts worn or damaged in transmission Remove transmission suction screen. Inspect for metal particles. Repair as necessary
Low or no lube Do Converter-Out and Lube Pressure Test. Do Transmission Pump Flow Test
Incorrect type of oil Change oil
High oil level Drain some oil
Low oil level Add oil
Air leak on suction side of pump Check oil pickup tube on side of transmission
Unit Vibrates
Problem Solution
Aerated oil Check and add oil
Failed universal joints on transmission drive shaft or differential drive shafts Check universal joints
Unit Lacks Power And Acceleration
Problem Solution
Engine fast idle speed set too low Check fast idle adjustment
Incorrect transmission oil Check oil
Aerated oil Check and add oil
Low transmission pressure Do Transmission System Pressure Test.
Warped transmission clutch Do Transmission Clutch Drag Checks
Brake drag Do Brake Drag Check
Clutch cut-off valve sticking Remove and inspect clutch cut-off valve
Low engine power Do Engine Power Test
Torque Converter Stall RPM Too High
Problem Solution
Aerated oil Put clear hose on thermal bypass outlet port. Run unit to check for bubbles in oil
Converter relief valve stuck open Do Converter-Out Pressure Test
Torque converter seal leakage Do Converter-Out Pressure Test
Torque converter not transferring power (bent fins, broken stator) Remove and inspect torque converter
Torque Converter Stall RPM Too Low
Problem Solution Low engine power Do Engine Power Test
Mechanical malfunction Remove and inspect torque converter