Issue Summary:
- Before or after overhaul, vehicles equipped with the Chrysler 46RE may exhibit a recurring diagnostic trouble code P1740 (torque-converter-clutch or over-drive-solenoid performance) or P0740 (torque-converter slip).
- Vehicles equipped with the 4F27E may exhibit a neutral condition in 4th gear after the transaxle reaches normal operating temperature.
- Changes to the final-drive gears in the Ford 4F27E transaxle, beginning with December 2000 production, resulted in different gear ratios.
- After overhaul, a Ford CD4E transaxle may generate code P0741 after the engine reaches operating temperature.
Vehicles equipped with the 46RE may exhibit a recurring diagnostic trouble code P1740 (torque-converter-clutch or overdrive-solenoid performance) or P0740 (torque-converter slip) before or after over-haul.
The cause may be that the mating surface, as shown in Figure 1, between the pump body and the pump stator is not flat, causing a loss of line pressure and torque-converter apply pressure.
Refer to Figure 2 for port identification of the pump body and pump stator.
To determine whether the stator surface is flat, you can use Pressurex® film. This product from Sensor Products Inc. (www.sensorprod.com) uses microcapsules of a paint-like substance that changes color intensity depending on pressure. The higher the pressure, the brighter the color.
To correct this condition, have the face of the stator machined so that it is flat.
Vehicles equipped with the 4F27E transaxle may exhibit a neutral condition in 4th gear after the vehicle is hot.
The cause may be that the bonded solenoid gasket is leaking solenoid pressure that feeds shift solenoid A. This will cause the 3-4 shift valve not to stroke fully, creating neutral.
Replace the bonded solenoid gasket (see Figure 3).
Refer to Figure 4 for the location of the bonded gasket and Figure 5 for the remainder of the valve-body assembly.
- Bonded solenoid gasket (Ford part number) YS4Z-7Z490-AA
Beginning with December 2000 production, the 4F27E transaxle received a final-drive gear change. Tooth counts have changed, which also changes gear ratios.
These current gear ratios replace the previous gear ratios. The vehicle’s PCM also must receive a calibration update to accommodate these new gear ratios to avoid shift-timing concerns.
Locate the vehicle certification label (VCL) (refer to Figure 6) to determine which gear ratio the transaxle originally had.
Figure 7 shows an example of the VCL. It shows the location of the axle code and the previous and current axle codes and gear ratios. The previous gear ratios are no longer available.
Better engine performance.
The tooth count of the final-drive input gear has changed from 87 to 59. The tooth count of the transfer-shaft input gear has changed from 83 to 57. The final-drive ring gear and its mating gear on the input transfer gear have not changed, as shown in Figure 8.
Ford made a new PCM calibration available to accommodate the new gear ratio. An authorized PCM modification label (see Figure 9) should be placed near the vehicle emission label.
The new final-drive and transfer-shaft input gears or an exchange transaxle that contains the new gear sets can be used in any 2000 or 2001 vehicle with a previous gear ratio as long as the PCM calibration upgrade is installed.
- Transaxles that have a part number beginning with X (example: XS4P) contain the previous gear ratio.
- Transaxles that have a part number beginning with 1 (example: 1S4P) have been built with the new gear ratios.
- The part number is on the ID tag, which is on top of the transmission as shown in Figure 10.
Some vehicles equipped with the CD4E transaxle, after overhaul, may store trouble code P0741 in memory after the engine is up to operating temperature. You also should notice converter slippage when you monitor it on the scan tool.
One cause may be mistaken installation of a mismatched turbine shaft and torque converter. The turbine shaft and the oil-pump drive shaft for vehicles with the 2.0- and 3.0-liter engines are about 5/8 inch shorter than those for vehicles with the 2.5-liter engine (refer to figures 11 and 12). If you install the short turbine shaft in a vehicle with the 2.5-liter engine, the vehicle will exhibit the concerns mentioned.
Figure 13 provides torque-converter identification, and as you can see in the dimension chart, there is about 5/8 inch difference in converter heights.
Remove the transaxle and ensure that it has the proper turbine shaft and oil-pump drive shaft for the engine size that the vehicle has. Refer to Figure 11 to identify the turbine shaft, Figure 12 to identify the oil-pump drive shaft and Figure 13 for converter identification.
October 2005 Issue
Volume 22, No. 10
- Chrysler 46RE: Recurring P1740 or P0740 When Hot
- Ford 4F27E: Neutral in 4th When Hot
- Ford 4F27E: Gear-Ratio Change
- Ford CD4E: Code P0741 Stored After Rebuild: Updated Information
