Ford vehicles equipped with the 5R110W transmission may have numerous diagnostic trouble codes set for the transmission-range sensor, including P0706, P0708 and P1705; speed-sensor faults ranging from P0715 to P0722; and/or a no-start condition.
The cause may be a shorted electronic-fan-clutch speed sensor (Figure 1) drawing down the reference voltage to the transmission-range sensor and the turbine-and output-speed sensors, which are indirectly connected through the PCM. This may cause these sensors to provide inaccurate information to the PCM and, of course, a no-start situation if the transmission-range sensor is not operating.
Refer to Figure 2 for a connector identification for PCM Connector C, the connector to which the electronic-fan-clutch speed sensor is wired, also shown in the partial schematic in Figure 3.
Terminal 46 is the reference voltage to the speed sensor, which is housed inside the fan clutch. Refer to Figure 4 and note that terminal 1 of PCM connector B is the reference voltage for the transmission-range sensor and the turbine-, intermediate- and output-speed sensors, also shown in the partial schematic in Figure 5. These circuits are connected internally in the PCM, and if there is a short it can affect the reference voltage to all.
To correct this condition, locate the connector for the electronic fan clutch (Figure 6), which is on the driver side of the fan shroud, and simply disconnect it. Clear all DTCs and drive the vehicle again to see whether the codes reset and/or see whether the vehicle starts. If all is well, replace the fan-clutch speed sensor as necessary.
A complaint of a flared 2-3 shift may occur before and/or after over-haul.
One cause may be excessive band clearance. This will affect the shift overlap during the release of the 1-2 reverse clutch (B5) and the apply of the third-gear band (B4) during the 2-3 shift process. If band travel is excessive, the B5 clutch releases before the B4 band applies, causing a flare.
Band travel should be between 1/8 (0.125) inch and 3/16 (0.1875) inch. If the travel is greater, the band’s pin length will need to be extended. There are two different styles of servos being used in the AW five-speed front-wheel-drive transmission, which is called the AW55-50SN in Saab and Volvo, RE5F22A in Nissan and AF33-23 in Saturn.
Figure 7 illustrates the Saab-, Volvo- and GM-style servo on the left and the Nissan-style servo on the right. Five different pin lengths are available for either style of servo, each identified by the number of ring grooves found at the tip of the pin.
Saab, Volvo & GM (GM part number)
- 0 ring grooves (3.000 inches) . . . . . . . . .24220756
- 1 ring groove (3.019 inches) . . . . . . . . .24220757
- 2 ring grooves (3.039 inches) . . . . . . . . .24220758
- 3 ring grooves (3.059 inches) . . . . . . . . .24220759
- 4 ring grooves (3.078 inches) . . . . . . . . .24220760
- 0 ring grooves (2.508 inches) . . . . . .31615 8Y005
- 1 ring groove 2.528 inches) . . . . . .31615 8Y004
- 2 ring grooves (2.548 inches) . . . . . .31615 8Y003
- 3 ring grooves (2.568 inches) . . . . . .31615 8Y002
- 4 ring grooves (2.588 inches) . . . . . .31615 8Y001
Regardless of new or remanufactured valve bodies, new or rebuilt solenoids and/or shift-adapt resets, the transmission continues to experience various shift bumps and clunks, especially on downshifts.
One cause can be attributed to opposing forces between the drive transfer gear and the driven transfer gear causing case wear (Figure 8). As the side loading continues, excessive clearance is created between the bearing support and the case, causing excessive lateral movement. This will spin the two bushings in the rear carrier, which are poorly supported to begin with, and cause the failure of various other bushings.
As bushing wear develops, lube pressure drops. Lube pressure is supplied between clutch-apply and counterbalance pistons to assist in clutch application and release.
Between excessive gear-train clearances and a loss of lubrication, various clunks and bumps occur during upshifts and, most notably, coast downshifts.
Lube pressure can be checked at the lube-pressure service port in the end cover (Figure 9). Lube pressure can be high as 30 psi when temperature is -10° F, but at 150° F normal lube pressure is about 5 psi in Drive and 8 psi in Reverse. If you observe 0-3 psi at operating temperature, the bushings are worn. If the valve body has not been replaced, a loss of lube pressure may also be attributed to worn main or secondary pressure-regulator valves.
The bushing-wear issue can be corrected by installing a bushing kit available from Omega Machine & Tool.
The rear carrier with the two-piece bushing has to be sent to Omega, which will machine the carrier and install a one-piece bushing (Figure 10).
The case can be corrected by Omega as well as by having it re-sleeved (Figure 11).
Omega Machine & Tool
800-601-7722 or omegamachine.com
May 2011 Issue
Volume 28, No. 5
- 5R110W: Transmission-range-sensor/speed-sensor faults or no start
- AW55-50SN/RE5F22A/AF33-23: Flared 2-3/servo differences
- AW55-50SN/RE5F22A/AF33-23: Clunks and bumps