Issue Summary:
- After overhaul, Ford and Mazda vehicles equipped with the 4F27E/FN4A-EL transaxle may exhibit a delayed engagement or a low-pressure condition.
- Before or after overhaul, a Ford vehicle equipped with the 4F27E transaxle may exhibit a complaint of a sliding or flared 2-3 upshift.
- A 2005-2006 Dodge truck or Jeep with a 42RLE has a lack of power when backing up an incline while loaded or pulling a trailer.
- A new governor-solenoid conversion kit is available for the RE-series transmission to improve reliability and performance.
After overhaul, Ford and Mazda vehicles equipped with the 4F27E/FN4A-EL transaxle may exhibit a delayed engagement or a low-pressure condition.
Note: Pressure will be normal in the Park position but when the selector is moved to Reverse or any forward range, the gauge will drop to 25-35 psi, producing the delayed engagement.
The cause may be that during valve-body overhaul, the solenoid-body to spacer-plate gasket with screens was assumed to be the updated bonded-gasket and plate assembly because with the incorporated screens in the gasket it becomes much stiffer. When a rebuilder uses this gasket alone, thinking it is the bonded plate, there is not enough support in the gasket with the absence of the small spacer plate. As a result, it cannot seal off the D, Second, Low and Reverse circuit from an exhaust port in the solenoid body (Figure 1).This condition will allow for normal line pressure in Park but low pressure in Reverse and all forward ranges.
Install the missing spacer plate with new individual gaskets (Figure 2). If the valve body came with the bonded solenoid-gasket assembly, replace it with the part number in service information, as aftermarket kits do not supply the updated bonded plate, only the individual gaskets.
Refer to Figure 3 for the remainder of the valve-body assembly.
- Bonded solenoid gasket (Ford part number) . . . . . . . .YS4Z-7Z490-AA
Before or after overhaul, a Ford vehicle equipped with the 4F27E transaxle may exhibit a complaint of a sliding or flared 2-3 upshift. The direct clutches or band may show signs of slipping by being darkened or burned.
One cause may be a worn servo bore in the case.
The partial hydraulic schematic in Figure 4 illustrates that during the 2-3 upshift, shift solenoid E (PWM) is pulsed off by the PCM. When this occurs, line pressure from the manual valve is not exhausted at the solenoid. Instead, it travels through the solenoid and is directed to the L/R shift valve. The fluid passes through the L/R shift valve and is then directed to the clutch control valve (passes through the clutch control valve as direct-clutch oil to apply the direct clutch) and the 3-4 shift valve (passes through the 3-4 shift valve as servo-release pressure to release the 2-4 band).
When this transmission is commanded to make an upshift into 3rd gear, servo-release pressure is fed to the spring side of the 2-4 band servo and direct-clutch pressure is fed to the direct clutch. If the case is worn in the servo bore where the servo-piston pin travels, a leak will occur. If the leak becomes great enough, a reduction in direct-clutch pressure may occur, allowing the band to release before the direct clutch is fully applied and causing an over-speed condition, or the band may not release completely when the direct clutch is applied, creating a slight tie-up and causing the band to burn.
Repair the case servo bore using the reamer tool and bushing kit from Northland Transmission.
Installing the bushing in the case will require removal of the oil pan, valve-body assembly and internal shifter linkage. The servo can then be removed and the boring tool installed to perform the fix. Refer to Figure 5 for an exploded view of the servo and internal linkage parts.
- Northland Transmission Inc. 105 E. Poplar Ave. Cameron, WI 54822
- Phone: 715-458-2617
- Fax: 715-458-2611
- Web site: www.servobore.com
A 2005-2006 Dodge truck or Jeep equipped with the 42RLE transmission comes in with a complaint of a lack of power when backing up an incline with the vehicle loaded or when pulling a trailer. A scan of the PCM may produce Code P1713 Restricted Manual Valve in T2 Range or P1776 Solenoid Switch Valve Latched In The L/R Position.
Incorrect PCM software hinders hill-climb capability in reverse.
Selectively erase and reprogram the PCM with new software revision level 63.3 or higher (Figure 6).
This kit was specifically designed to improve the reliability of the governor solenoid in normal use and to handle higher base pressure in high-performance applications.
Refer to Figure 7 for the contents of the new governor solenoid and manifold.
Refer to Figure 8 for a view of the previous-design governor solenoid and its components.
Refer to Figure 9 to see that the new manifold can be used with both the early and late transducers.
Refer to Figure 10 for a view of the new manifold and solenoid installed.
July 2010 Issue
Volume 27, No. 7
- Ford/Mazda 4F27E/FN4A-EL: Delayed engagement/low pressure
- Ford 4F27E: 2-3 upshift concerns
- Dodge/Jeep 42RLE: Low power in reverse
- Chrysler/Dodge/Jeep RE-Series Transmission