GeorgeGhia

That is very interesting info, that would be set up for the heat exchanger temperature range I guess, can it be adjusted?, also interesting that the line below it says "Minimum temperature for activation is 20C'. Where did you get the info from?

Brilliant write up and excellent work, well done👏, El Andrew. Great taste in beer too I see🇦🇺👍 Cheers, George

http://www.fordforums.com.au/showthread.php?t=11441275

Hi jules_1972, As you can't go to Ford Forum here's copy of a post from my stream, includes extract from my Ford BF workshop manual. It has taken me a while to take in the significance of the call from ZF, I had emailed them about 2 weeks ago and received confirmation of my query, but was beginning to think that was all I would get, but Yes, the information received from the ZF tech is invaluable and I now feel we can be totally confident that the decision to remove the Ford heat exchanger and install an air/cooler was the right one. No risk of Milkshake and longer transmission/fluid life.My first thought was to share the info with my fellow forum members, and then armed with the new info I read through my Ford workshop manual transmission section again. I now have a much better understanding of how the ZF6 operates and have since done some more monitoring of my transmission temp and functions. I felt that the most important pieces of info to come from ZF was the minimum optimum operating temp of 30C for the ZF6, that ZF6 has a designed in strategy to bring the trans fluid up to that temp from a cold start, that ZF test run the ZF6 as low as minus 20C, and it is beneficial to the life of the trans and fluid to run at lower temps. As I have always said, the ZF6 is very smart.It is obviously desirable that we run our trans at optimum operating efficiency and so to this end it would be good to have it running at a minimum of 30C sooner rather than later. The ZF6 has a designed in strategy for this and we probably don't need to do anything, but, as I do a lot of short runs I thought I would try different strategies to help warm up the trans from cold starts, also thought our friends in colder climes would be interested to know.Here's the results of recent test runs on cooler MELBOURNE mornings.Strategy1:A/C on auto 21.5C, Manual shift for first 5mins then Auto.Ambient temp 16C, Start up engine temp 44C, trans temp 19C, after 5mins, engine temp 80C, trans temp 30C.after 10mins, engine temp 85-92C, trans temp 40-43C.Strategy2:A/C on auto 21.5C, Auto shift.Ambient temp 19C, Start up engine temp 43C, trans temp 21C,after 5mins, engine temp 85C, trans temp 30C.after 10mins, engine temp 85-92C, trans temp 39-42C.Not a lot in it really, think I will leave to the trans to look after itself,smarter than me I think.Here's an extract from my Ford BF Workshop Manual re the ZF6 transmission which explains among other things how the trans temp is monitored and regulated.DESCRIPTION AND OPERATIONTransmission Electronic SystemThe transmission control module (TCM) and its input/output network control the following transmission operations:Shift timing.Line pressure (shift feel).Torque converter clutch.In addition, the TCM receives input signals from certain transmission-related sensors and switches. The TCMalso uses these signals when determining transmission operating strategy.Using all of these input signals, the TCM can determine when the time and conditions are right for a shift, or when to apply or release the torque converter clutch. It will also determine the pressure needed to optimize shift feel. To accomplish this, the TCM uses six pressure control solenoids and one shift solenoid to control transmission operation.The following provides a brief description of each of the sensors and actuators used to control transmission operation.TCMCAUTION: Should you be required to reprogram the TCM the following criteria must be observed:-The transmission fluid temperature must be below 80°CPark (P) or Neutral (N) selectedThe handbrake firmly appliedThe TCM for the transmission is mounted on top of the main control valve body. The control module for the transmission has been designed to operate correctly in the environment in which the TCM is located.The transmission control module is activated and deactivated by the ignition supply and is connected to the transmission link harness by a 16-way connector.The TCM controls the operation of the transmission. The TCM processes information received in both analogue and digital form such as:Transmission input speedOutput speedThrottle pedal position Gear selector position Engine torqueEngine speed Transmission fluid temperatureBrake pedal statusEngine oil temperature Coolant temperatureABS wheel speedThis information is then used by the TCM to decide which shift pattern to select and for shift energy management. Electro-hydraulic solenoid valves and pressure regulators control the transmission gear changes.Five pressure regulators and one solenoid valve are used to control direct transmission fluid flow to select internal clutches and control the fluid pressure at the clutch. A separate pressure regulator is used exclusively for torque converter clutch control.The TCM monitors all TCM inputs and outputs to confirm correct system operation. If a fault occurs the TCMis able to perform default action and inform the driver of the problem, this is by the instrument cluster message centre.SolenoidsThe hydraulic module contains one solenoid valve. The solenoid valve is actuated by the TCM and has two positions of open or closed, it is used to switch the position valve.There are six electronic pressure control valves, these convert an electric current into a proportional hydraulic pressure. They are energized by the TCM and actuate the valves belonging to the relevant switching elements.Controller Area Network (CAN) InterfaceFor the TCM to be able to perform shift point and shift quality management a number of external signals are required. For shift point management alone the TCM requires output speed sensor, throttle pedal position, brake pedal status and gear selector position. The controller area network (CAN) bus is used to share information between control modules. The TCM obtains most of its required data over the CAN bus from the electronic engine controls, Sequential Sport Shifter and ABS, Instruments pack and diagnostic tools.Brake Pedal Position (BPP) SwitchThe brake pedal position (BPP) switch tells the TCM when the brakes are applied, and disengages the torque converter clutch. The BPP switch closes when the brakes are applied and opens when they are released. The BPP is also used to disengage the brake shift interlock and stops gradient calculations.Engine Coolant Temperature (ECT) SensorThe engine coolant temperature (ECT) sensor detects engine coolant temperature and supplies the information to the TCM. The ECT sensor is used to control the torque converter clutch (TCC) operation.Accelerator Pedal Position (APP) SensorThe accelerator pedal position (APP) sensor is a potentiometer mounted on the accelerator pedal. The APP sensor detects the position of the accelerator pedal and sends this information to the electronic control module (ECM). The APP sensor is used for shift scheduling and TCC lock-up.Input Shaft Speed (ISS) SensorThe input shaft speed (ISS) sensor is a Hall Effect type sensor.The ISS sensor is mounted internally on the transmission and is located on the TCM and main control valve body unit.Output Shaft Speed (OSS) SensorThe output shaft speed (OSS) sensor is a Hall Effect type sensor.The OSS sensor is mounted internally on the transmission and is located on the TCM and main control valve body unit and is used for shift scheduling.Transmission Fluid Temperature (TFT) SensorThe TCM utilizes one transmission fluid temperature sensor located on the main control valve body. The TCMuses the sensor input to activate various shift strategies. The sensor is in the form of a temperature dependent resistor.The temperature sensor performs plausibility checks on each sensor reading. Obviously, the transmission oil temperature should not jump in value excessively between sensor readings. If the inputs from the temperature sensor are outside the working range it possible that the sensor is short or open circuit.Position sensorThe TCM uses the position of this switch housed on the TCM and main control valve body, to determine the selected gear range on the Automatic side of the selector lever. The selector lever is connected to the transmission by a cable, which operates the transmission selector shaft between positions Park, Reverse, Neutral and Drive. The TCM detects the driver’s choice of manual range selection (+ or -) by means of a 3-bit code generated by the printed circuit board (PCB) housed within the selector assembly. This 3-bit code is then transformed in to a CAN message by the PCB and transmitted on to the CAN bus where it is detected by the TCM.The TCM uses this information to generate the CAN message "Gear Position Selected", which must not be confused with the similar message "Gear Position Actual" indicating the current mechanical gear ratio activated by the TCM.Movement of the lever between Park, Reverse, Neutral and Drive manually controls the flow of transmission fluid, the TCM having control of the forward gear selected in Drive. Additional movement of the lever to 5, 4, 3 and 2 positions does not manually modify the fluid flow, the TCM detects these positions, and controls the gear selected electronically.Sport mode shifter positionThe sport mode:Allows the driver to select or de-select the automatic transmission sport mode.Allows the automatic transmission to operate normally when the sport mode is selected, but under acceleration the gear shift points are extended to make full use of the engine’s power reserves.Allows the driver to drive the vehicle in the "D" position with the full automatic transmission shift or manually shift the gears through 2nd, 3rd, 4th, 5th and 6th gear by using the + and - positions."S" is illuminated when Sport mode is selected.Communicates with the TCM through the CAN network to show the sport mode switch status.TCM Monitoring FunctionsAs explained above the TCM monitors all input and outputs to identify possible failures. If a fault is detected the TCM takes the appropriate action to ensure the transmission enters a safe mode of operation, without sacrificing transmission durability or driver safety.Supply MonitoringIf the battery voltage is either too great or too low, the TCM will detect a fault condition. For the TCM to be able to identify this fault the engine must be running and the transmission fluid temperature sensor must be functioning correctlyDESCRIPTION AND OPERATION (Continued)monitoring function evaluates the voltage characteristics during the switch on process checking for the above faults.All solenoid outputs are fully protected. The processor and the appropriate fail-safe action taken can quickly identify open and short circuit faults.Sensor Supply MonitoringThe sensor supply voltage is a stabilized supply. This supply is monitored by the micro-processor by an Analogue to Digital Converter (ADC). If the voltage is out of the valid tolerance a raise a diagnostic trouble code (DTC) is set and the appropriate fail-safe action is performed.Electronically Erasable Program Read Only Memory (EEPROM) MonitoringCAUTION: Should you be required to reprogram the TCM the following criteria must be observed:-The transmission fluid temperature must be below 80°CPark (P) or Neutral (N) selectedThe handbrake firmly appliedTo diagnose errors with the electronically erasable program read only memory (EEPROM) the TCM calculates 4 checksums continuously: If the processor identifies discrepancies in any of the four checksums the TCMwill engage mechanical limp-home mode.The TCM can diagnose errors within the EEPROM. Diagnosis is only performed during TCM initialization. There is no fail-safe mechanism associated with this function as the EEPROM is mainly used for the storage of fault codes and transmission calibration adaptations. If a fault occurs the TCM is able to perform default action and inform the driver of the problem, this is by the instrument cluster message centre.Watchdog MonitoringThe watchdog monitoring function has two functions. Firstly it checks that it is possible to inhibit output control by the activation of the solenoid supply transistor. Secondly the watchdog checks that the safety circuit is functioning correctly.During initialization the watchdog checks that it is possible to inhibit control of the pressure regulator and solenoid valves by switching the solenoid supply transistor. There is a fault if activation of the solenoids cannot be inhibited by the watchdog (NB. The supply to the solenoids can still be inhibited by the high side switch responsible for control of each solenoid I.e. One safety path is lost).Monitoring the Substrate Temperature SensorThe TCM is situated within the transmission on the valve body. As the TCM controls a number of high power solenoids and is surrounded by ATF, the TCMcan obviously get very hot. If the temperature of the hardware rises above a pre-determined level the TCMwill be shut down. Prior to the TCM shutting down the TCM will log a fault code, during shutdown the transmission will enter mechanical limp-home mode. Monitoring of the substrate temperature is performed by a temperature dependent resistor mounted on the processor.Plausibility CheckingThe TCM detects a fault if an excessive voltage jump is identified between any two consecutive measurements. Also, with the engine started from cold the transmission fluid temperature will start to rise. Therefore the substrate or fluid temperature will also start to rise because the TCM is surrounded by transmission fluid. If the engine and output shaft speed is higher than a set threshold for a predetermined length of time without the substrate temperature rising above a set threshold a fault will be detected.Pressure Regulator/Solenoid MonitoringEach pressure regulator and solenoid is monitored for open circuits and short circuits. The TCM also checks that the current being delivered to each solenoid valve or pressure regulator is within valid limits. When each solenoid is being driven with minimum current the TCM checks that the current is not above a threshold value. If a solenoid is being driven with maximum current, it checks that the current is not below a valid threshold. If either of these two errors occur, a plausibility error is logged and the appropriate fail-safe action is performed.Output Speed MonitorIt is possible for the TCM to diagnose electrical errors associated with the output speed sensor while the vehicle is stationary as well as moving. Plausibility monitoring is performed on the sensor output when the vehicle is moving.Input Speed MonitorIt is possible for the TCM to diagnose electrical errors associated with the input shaft speed sensor while the vehicle is stationary as well as moving. Plausibility monitoring is performed on the sensor output when the vehicle is moving.Transmission Fluid Temperature Sensor MonitoringThe TCM monitors for faults associated with the transmission fluid temperature sensor in the following ways:1. Open and short circuit fault detection.2. The temperature cannot alter by more than a predefined differential between any two consecutive measurements.3. The transmission fluid temperature must rise after the engine has been started provided that the fluid temperature was low enough to begin with (The vehicle must be driven and the diagnostic test condition met). Torque Converter Lock-up ControlThe TCM controls how the torque converter clutch is engaged as a function of the accelerator pedal position, output speed, transmission fluid temperature, gear selected and shift program. Lock-up is possible in all forward gears, but usually it is restricted to fourth, fifth and sixth gears. To make use of the comfort enhancing effect of the torque converter, the converter clutch can be disengaged prior to a downshift or up-shift. The torque converter lock up clutch is always modulated to allow for controlled slip, to further improve the shift quality. "Let's eliminate the Milkshake"Regards, George

Sorry, it's not an issue to answer anyone with sensible questions/comments, some people annoy me with their stupid comments, am too old for that. From what I can tell from my FORScan monitoring of the trans the torque converter slip appears to be less once the fluid temp gets above 30C and only happens in 1,2 and 3 gears. Gets to 30C within 3-4 mins of start up regardless of the ambient temp and gets there before the engine reaches its normal running temp. The ZF6 monitors its internal temp and looks for an increase in fluid temp from start up, and then looks for a steady running temp, (not fluctuating greatly from one reading to the next) with a max of 120C, provided those requirements are met it will run happily from minus 20C to 120C. Since fitting the cooler my trans is running in 40C range on short runs and 50-60C range on longer runs. Cooler running temps are better for the trans and its fluid, and extend the life of the fluid. Regards,George

Simply put - Torque converter slip is used to heat the trans fluid. For those who are prepared to take the blinkers off and spare us from inane comments read here: http://www.fordforums.com.au/showthread.php?t=11441275

The warm up strategy has got nothing to do with the heat exchanger, it is designed into the ZF6 programming, I have been monitoring my trans temp for some time now since removing the heat exchanger and fitting the air/oil cooler, trans gets up to its optimum minimum operating temp before the engine gets to its operating temp in ambients of 5-43C. The ZF6 has been test run at minus 20C and will run happily at temperatures below its optimum minimum temp of 30C. The optimum temp range is for max efficiency. I am averaging trans temp of 55-60C and warms up to 30C after 3-4mins driving, The cooler running temps extend the life of the trans and its fluid. Take a look here for full story and lots of qualified info on ZF6: http://www.fordforums.com.au/showthread.php?t=11441275 The primary reason for fitting the cooler was to totally eliminate the risk of a "Milkshake".

Hi All, I have been asking the question, "what is the recommended operating temperature for the ZF6?", for some time, today I received a personal phone call from a ZF technical representative in answer to my question. I was driving my car and was also monitoring my transmission temperature at the time so his timing could not have been better, we had a very interesting discussion. Here's the gist of what was discussed by phone and later email. We discussed the details of my car, the fact that I had removed my heat exchanger from my car and had had installed a suitably sized PWR air/oil cooler mounted in front of the a/c condenser, connected to the trans with 12mm hose, without thermostat, and was averaging trans temp of 58C after ½hr driving, warm up period of 5mins to approx 35C from 23C on average. Provided the cooler and connecting hoses are correctly sized, the fitting of an air/oil cooler to a ZF6 is not detrimental to the operation of the ZF6, and will extend the life of the transmission and fluid. Lower running temperatures are beneficial to the life of the transmission and fluid. ZF6 transmissions are test run at start up temperatures as low as -20C. It is critical that ZF6 Lifeguard fluid is used. The ZF6 generates its own heat at start up to attain minimal running temperature of 30C. By Email: Hi George, Normal transmission operation for ZF 6HP26 is between 30 – 120 degrees C. Before 30 degrees C we have warm up strategy and after 120 degrees C the transmission will enter high temperature strategy (Hot mode). Oil checking overflow level is a 40 degrees C and depending on climate normal transmission oil sump temperatures can vary between 60 and 100 degrees C. I don't see any issues with the temperatures you are talking about providing the oil flow to the transmission has not been restricted. As your operation temps are lower I see this as a benefit for extending the service life of the oil. Kind regards Your ZF Service Desk ZF Friedrichshafen AG 88038 Friedrichshafen,Germany So in the opinion of a qualified ZF technical representative a correctly installed air/oil cooler is beneficial to life of a ZF6 transmission and its fluid. Cooler running temperatures as low as 30C are within the recommended operating temperatures and better for the ZF6 and Lifeguard fluid. Very pleased to have finally got some qualified answers, thanks ZF. Hope this information helps all my fellow forum members. Regards, George Also take a look here:http://www.fordforums.com.au/showthread.php?t=11441275 "Let's eliminate the Milkshake" __________________ 2007 Ford Fairmont BF Mk11 Sports Ghia 4L ZF 6 Auto in Ego/Warm Charcoal Leather, PWR Air/Oil Tran's Cooler, Formula 1 Tint, Parrot CK3000: Transmission service Trevor, Transdoctor 372a Settlement Rd Thomastown,Victoria 3074 T: 0435-928-517 transdoctor@hotmail.com Previous : 1997 Ford Fairmont Ghia EL Tickford 4L 3 Speed Auto Heritage Green 1995 Ford Falcon XL GL 4L 3 Speed Auto Silver 1979 Ford Fairmont Ghia 4L 3 Speed Auto Arctic Blue