Transmission problems
#1
11-18-2019, 09:19 AM
Transmission problems
Ill start by saying i have searched and cannot find the answer i am looking for, so some guidance would help.. thanks in advance.
My son has an 04 disco2.
A few months back he was driving and smelled transmission fluid... he immediately pulled over. I met him and took some tools. When i removed the transmission fill plug it was completely full of black fluid, I mean WAY overfilled...
We got it home and changed the fluid and filter a few times to try and flush it out... It never really drove right afterwards. shifted funny, felt like was jumping in and out of gear a little...
Two weeks ago it finally died. I ordered a used transmission that was from a wrecked disco2 that had 5K miles on a rebuild...
Shop that installed it said it looked great, fluid was perfect, etc... no signs of issues.
He drove it friday and it drove perfect. We went offroad friday night with friends and it was 100% fine.
I rode with him Saturday morning and it drove fine, Except for what i felt was high RPM at 50 mph.. He has 33' tires so at 50 i think 2300 rpm was a little high...but there was no slipping, funny shifts, etc...
We got back to the house and when he started it a few hours later it wouldn't move, it just revved.
the gear selector in the dash was working, and showing the correct gear so i dont think it was the XYZ switch.
after messing around with it for a few min it engaged. BUT it was acting funny so we immediately parked it.. the fluid level/color if fine.
My question is this:
can the trans computer cause this? the reason i ask is because a few months back he drilled a hole under the drivers seat for an AMP cable, but didn,t use it, and he has an amp on top of the trans computer.
SInce he was "wheeling through some deep mud/water ( he recently installed a snorkel), and it was pouring when we were driving saturday, could the trans computer have gotten wet. I know the water he went through was above the level of the computer, and with the 1/2" hole in the floorboard it very well could have gotten wet.
We pulled the codes and it showed a MAF low voltage code and p0758.
anything to check BEFORE i call the transmission supplier.... i paid for a shop to install is so there would be no warranty issues, but i will to do the next swap, as the shop will charge me labor again for the next one if the trans is bad... thanks
My son has an 04 disco2.
A few months back he was driving and smelled transmission fluid... he immediately pulled over. I met him and took some tools. When i removed the transmission fill plug it was completely full of black fluid, I mean WAY overfilled...
We got it home and changed the fluid and filter a few times to try and flush it out... It never really drove right afterwards. shifted funny, felt like was jumping in and out of gear a little...
Two weeks ago it finally died. I ordered a used transmission that was from a wrecked disco2 that had 5K miles on a rebuild...
Shop that installed it said it looked great, fluid was perfect, etc... no signs of issues.
He drove it friday and it drove perfect. We went offroad friday night with friends and it was 100% fine.
I rode with him Saturday morning and it drove fine, Except for what i felt was high RPM at 50 mph.. He has 33' tires so at 50 i think 2300 rpm was a little high...but there was no slipping, funny shifts, etc...
We got back to the house and when he started it a few hours later it wouldn't move, it just revved.
the gear selector in the dash was working, and showing the correct gear so i dont think it was the XYZ switch.
after messing around with it for a few min it engaged. BUT it was acting funny so we immediately parked it.. the fluid level/color if fine.
My question is this:
can the trans computer cause this? the reason i ask is because a few months back he drilled a hole under the drivers seat for an AMP cable, but didn,t use it, and he has an amp on top of the trans computer.
SInce he was "wheeling through some deep mud/water ( he recently installed a snorkel), and it was pouring when we were driving saturday, could the trans computer have gotten wet. I know the water he went through was above the level of the computer, and with the 1/2" hole in the floorboard it very well could have gotten wet.
We pulled the codes and it showed a MAF low voltage code and p0758.
anything to check BEFORE i call the transmission supplier.... i paid for a shop to install is so there would be no warranty issues, but i will to do the next swap, as the shop will charge me labor again for the next one if the trans is bad... thanks
Last edited by yardpro; 11-18-2019 at 11:38 AM.
#2
11-18-2019, 12:02 PM
when you say that the transmission was "WAY overfilled," were you checking it with the engine running? if you check the level with the engine off, you should get fluid pouring out. the fluid level is supposed to be up to the bottom of the filler hole when the engine is running.
if your new transmission is underfilled, that may be the cause of your problem.
if your new transmission is underfilled, that may be the cause of your problem.
#3
11-18-2019, 12:17 PM
yes, it was checked with the engine running.
when we had the issue with the old trans, it looked like black water pouring out, so i immediately thought that trans cooler was integral with the radiator and there was a leak letting water into the trans fluid. But that's not the case with the disco's.
The "new" trans was also checked with the engine running.
it went from seemingly driving fine to nothing after being parked for a few hours.
when we had the issue with the old trans, it looked like black water pouring out, so i immediately thought that trans cooler was integral with the radiator and there was a leak letting water into the trans fluid. But that's not the case with the disco's.
The "new" trans was also checked with the engine running.
it went from seemingly driving fine to nothing after being parked for a few hours.
#4
11-18-2019, 01:00 PM
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#5
11-18-2019, 01:14 PM
when you rev it in gear, it feels like its in gear, it will rock forward a little, but not move... when it did finally engage it moved normally..
also i was wrong on the codes... sorry,
codes were 0734 and 0741
the guy that sole me the trans told me to check the XYZ and the brake switch...
i just spoke with my son and he did say the brake light is on on the dash and the parking brake is fully disengaged.
#7
11-18-2019, 04:32 PM
Rock Crawling
Generally speaking, incorrect gear ratios are 99% of the time a bad transmission.
The logic behind a gear ratio fault means that the car is logging input to the transmission, but the output speed is not matching up, so the clutches are slipping.
Are you sure fluid level is correct?
Fault diagnosis for p0734
DTC P0734
Gear ratio monitoring (4th gear).
Possible causes by suggested order of priority:
^ Output shaft signal not to specification.
^ Engine management ECM faults present.
^ Open circuit C243/E (K) to C193/42 (R).
^ Open circuit C243/F (B) to C193/14 (B).
^ Shaft speed electrical interference.
^ connectors C243,EAT C193.
^ Open circuit shaft speed sensorC193/14 (B) to C193/42 (R).
^ Shaft speed sensor fault.
^ Torque converter mechanical fault.
^ Gearbox mechanical fault.
Output Shaft Signal Not To Specification.
^ If using TestBook, the display shows the output shaft speed as measured by the transmission ECU and the engine speed as measured by the engine management ECM.
^ (If TestBook not available, use Live Data reading function on Scan Tool. [See Scan Tool manufacturers handbook for detailed instruction]).
CHECK THE FOLLOWING:
^ Check the gearbox specifications and ensure that the ratio of the engine speed against output shaft speed while in 4th gear is correct (drive vehicle on rolling road or road test).
^ At constant road speed with no gear changes both TestBook readings should be stable.
^ The two readings should also maintain the same ratio so long as no gear changes take place.
^ If the output shaft signal is unstable there may be a problem with the output shaft sensor circuit.
^ If the engine speed signal is unstable there may be a problem with the ECM or its sensors.
^ If the gear ratio is not to specification there may be a problem with the gearbox.
^ (If TestBook not available, use Live Data reading function on Scan Tool. [See Scan Tool manufacturers handbook for detailed instruction]).
POSSIBLE FAULTS
^ Output shaft sensor fault.
^ ECM or ECM sensors fault.
^ Gearbox mechanical fault.
Engine Management ECM Faults Present.
CHECK THE FOLLOWING:
^ Read ECM fault codes and check if any crankshaft sensor, engine speed, engine load/airflow or engine torque measurement faults are set.
^ Any faults present should be rectified.
POSSIBLE FAULTS
^ Faults set in ECM.
Open Circuit C243/E (K) To C193/42 (R).
CONNECTOR
^ Check for connector not correctly latched, backed out pins, damaged pins, corroded pins.
Open Circuit C243/F (B) To C193/14 (B).
OPEN_CIRCUIT
^ Check resistance > 1M Ohm
Shaft Speed Electrical Interference.
OPEN_CIRCUIT
^ Check resistance > 1M Ohm
Connectors C243,EAT C193.
OPEN_CIRCUIT
^ Check resistance > 1M Ohm
Open Circuit Shaft Speed SensorC193/14 (B) To C193/42 (R).
^ Use Live Data reading to display the output shaft speed as measured by the transmission ECU.
CHECK THE FOLLOWING:
^ With the engine running and the position switch in 'P' the shaft speed should measure 0 RPM.
^ If the reading is not 0 RPM then there may be a problem with electrical interference.
^ Check the connections to the screen around the output shaft sensor wiring.
POSSIBLE FAULTS
^ Faulty output shaft sensor wiring.
^ Faulty output shaft sensor.
Shaft Speed Sensor Fault.
^ Use Live Data reading to display the output shaft speed as measured by the transmission ECU.
CHECK THE FOLLOWING:
^ Monitor the road speed (from the vehicle speedometer) and the output shaft speed while driving on the road or on a rolling road.
^ The two readings should maintain the same ratio. If one reading doubles so should the other reading.
^ If the readings do not maintain a fixed ratio the output shaft sensor may be faulty.
POSSIBLE FAULTS
^ Faulty output shaft sensor
Torque Converter Mechanical Fault.
^ Use Live Data reading to display the output shaft speed as measured by the transmission ECU.
CHECK THE FOLLOWING:
^ Monitor the road speed (from the vehicle speedometer) and the output shaft speed while driving on the road or on a rolling road.
^ The two readings should maintain the same ratio. If one reading doubles so should the other reading.
^ If the readings maintain a fixed ratio the torque converter may be faulty.
POSSIBLE FAULTS
^ Transmission torque converter mechanical fault.
Gearbox Mechanical Fault.
CHECK THE FOLLOWING:
^ Ensure none of the electrical faults described in this section of the diagnostic are present.
^ Road test the vehicle. Ensure all gears are engaged during testing.
^ If the gearbox and vehicle behave abnormally there may be a mechanical problem with the gearbox.
POSSIBLE FAULTS
^ Gearbox mechanical fault.
P0741
DTC P0741
Lock-up clutch monitoring.
Possible causes by suggested order of priority:
^ Gear ratio fault present.
^ Engine Speed signal fault present (N_MOT invalid).
^ Solenoid lock-up clutch S/C or O/C fault present
^ Transmission mechanical fault (torque converter).
Gear Ratio Fault Present.
CHECK THE FOLLOWING:
^ Check if any gear ratio faults are present.
^ Diagnose the gear ratio faults and re-test the vehicle.
POSSIBLE FAULTS
^ Gear ratio fault is present.
Engine Speed Signal Fault Present (N_MOT Invalid).
CHECK THE FOLLOWING:
^ Check if an engine speed fault is present. This is indicated by a CAN message (N_MOT invalid).
^ Diagnose the fault and re-test the vehicle.
POSSIBLE FAULTS
^ Engine speed fault is present.
Solenoid Lock-up Clutch S/C Or O/C Fault Present.
CHECK THE FOLLOWING:
^ Check if a solenoid lock-up clutch S/C or O/C fault is present.
^ Diagnose the fault and re-test the vehicle.
POSSIBLE FAULTS
^ Solenoid lock-up clutch S/C or O/C fault is present.
Transmission Mechanical Fault (torque Converter).
CHECK THE FOLLOWING:
^ Carry out service procedure on the gearbox torque converter.
POSSIBLE FAULTS
^ Mechanical fault with transmission.
The logic behind a gear ratio fault means that the car is logging input to the transmission, but the output speed is not matching up, so the clutches are slipping.
Are you sure fluid level is correct?
Fault diagnosis for p0734
DTC P0734
Gear ratio monitoring (4th gear).
Possible causes by suggested order of priority:
^ Output shaft signal not to specification.
^ Engine management ECM faults present.
^ Open circuit C243/E (K) to C193/42 (R).
^ Open circuit C243/F (B) to C193/14 (B).
^ Shaft speed electrical interference.
^ connectors C243,EAT C193.
^ Open circuit shaft speed sensorC193/14 (B) to C193/42 (R).
^ Shaft speed sensor fault.
^ Torque converter mechanical fault.
^ Gearbox mechanical fault.
Output Shaft Signal Not To Specification.
^ If using TestBook, the display shows the output shaft speed as measured by the transmission ECU and the engine speed as measured by the engine management ECM.
^ (If TestBook not available, use Live Data reading function on Scan Tool. [See Scan Tool manufacturers handbook for detailed instruction]).
CHECK THE FOLLOWING:
^ Check the gearbox specifications and ensure that the ratio of the engine speed against output shaft speed while in 4th gear is correct (drive vehicle on rolling road or road test).
^ At constant road speed with no gear changes both TestBook readings should be stable.
^ The two readings should also maintain the same ratio so long as no gear changes take place.
^ If the output shaft signal is unstable there may be a problem with the output shaft sensor circuit.
^ If the engine speed signal is unstable there may be a problem with the ECM or its sensors.
^ If the gear ratio is not to specification there may be a problem with the gearbox.
^ (If TestBook not available, use Live Data reading function on Scan Tool. [See Scan Tool manufacturers handbook for detailed instruction]).
POSSIBLE FAULTS
^ Output shaft sensor fault.
^ ECM or ECM sensors fault.
^ Gearbox mechanical fault.
Engine Management ECM Faults Present.
CHECK THE FOLLOWING:
^ Read ECM fault codes and check if any crankshaft sensor, engine speed, engine load/airflow or engine torque measurement faults are set.
^ Any faults present should be rectified.
POSSIBLE FAULTS
^ Faults set in ECM.
Open Circuit C243/E (K) To C193/42 (R).
CONNECTOR
^ Check for connector not correctly latched, backed out pins, damaged pins, corroded pins.
Open Circuit C243/F (B) To C193/14 (B).
OPEN_CIRCUIT
^ Check resistance > 1M Ohm
Shaft Speed Electrical Interference.
OPEN_CIRCUIT
^ Check resistance > 1M Ohm
Connectors C243,EAT C193.
OPEN_CIRCUIT
^ Check resistance > 1M Ohm
Open Circuit Shaft Speed SensorC193/14 (B) To C193/42 (R).
^ Use Live Data reading to display the output shaft speed as measured by the transmission ECU.
CHECK THE FOLLOWING:
^ With the engine running and the position switch in 'P' the shaft speed should measure 0 RPM.
^ If the reading is not 0 RPM then there may be a problem with electrical interference.
^ Check the connections to the screen around the output shaft sensor wiring.
POSSIBLE FAULTS
^ Faulty output shaft sensor wiring.
^ Faulty output shaft sensor.
Shaft Speed Sensor Fault.
^ Use Live Data reading to display the output shaft speed as measured by the transmission ECU.
CHECK THE FOLLOWING:
^ Monitor the road speed (from the vehicle speedometer) and the output shaft speed while driving on the road or on a rolling road.
^ The two readings should maintain the same ratio. If one reading doubles so should the other reading.
^ If the readings do not maintain a fixed ratio the output shaft sensor may be faulty.
POSSIBLE FAULTS
^ Faulty output shaft sensor
Torque Converter Mechanical Fault.
^ Use Live Data reading to display the output shaft speed as measured by the transmission ECU.
CHECK THE FOLLOWING:
^ Monitor the road speed (from the vehicle speedometer) and the output shaft speed while driving on the road or on a rolling road.
^ The two readings should maintain the same ratio. If one reading doubles so should the other reading.
^ If the readings maintain a fixed ratio the torque converter may be faulty.
POSSIBLE FAULTS
^ Transmission torque converter mechanical fault.
Gearbox Mechanical Fault.
CHECK THE FOLLOWING:
^ Ensure none of the electrical faults described in this section of the diagnostic are present.
^ Road test the vehicle. Ensure all gears are engaged during testing.
^ If the gearbox and vehicle behave abnormally there may be a mechanical problem with the gearbox.
POSSIBLE FAULTS
^ Gearbox mechanical fault.
P0741
DTC P0741
Lock-up clutch monitoring.
Possible causes by suggested order of priority:
^ Gear ratio fault present.
^ Engine Speed signal fault present (N_MOT invalid).
^ Solenoid lock-up clutch S/C or O/C fault present
^ Transmission mechanical fault (torque converter).
Gear Ratio Fault Present.
CHECK THE FOLLOWING:
^ Check if any gear ratio faults are present.
^ Diagnose the gear ratio faults and re-test the vehicle.
POSSIBLE FAULTS
^ Gear ratio fault is present.
Engine Speed Signal Fault Present (N_MOT Invalid).
CHECK THE FOLLOWING:
^ Check if an engine speed fault is present. This is indicated by a CAN message (N_MOT invalid).
^ Diagnose the fault and re-test the vehicle.
POSSIBLE FAULTS
^ Engine speed fault is present.
Solenoid Lock-up Clutch S/C Or O/C Fault Present.
CHECK THE FOLLOWING:
^ Check if a solenoid lock-up clutch S/C or O/C fault is present.
^ Diagnose the fault and re-test the vehicle.
POSSIBLE FAULTS
^ Solenoid lock-up clutch S/C or O/C fault is present.
Transmission Mechanical Fault (torque Converter).
CHECK THE FOLLOWING:
^ Carry out service procedure on the gearbox torque converter.
POSSIBLE FAULTS
^ Mechanical fault with transmission.
#8
11-18-2019, 04:50 PM
Rock Crawling
#9
11-18-2019, 05:56 PM
Camel Trophy
#10
11-19-2019, 07:16 AM
This is what i am thinking.
It feels like there is not enough fluid pressure to "close" the clutch bands. it happened VERY suddenly. Usually when i have had an issue with transmission clutches they slowly get worse... This one went from working to the next time it started nothing..
This is why i was looking at electrical causes.. but pump failure makes sense.