- In the General Motors THM 4L80-E/4L80-EHD, no converter clutch, trouble code 68 in Overdrive and trouble code 39 in Drive 3 may be caused by an incorrectly installed TCC enable valve.
- A blown fuse in 1991-95 Cadillacs equipped with the THM 4T60-E can cause 3rd-gear starts before or after overhaul.
- In Saturn MP6/MP7 units, delayed or harsh reverse engagement and repeat failures of the external filter seal may be caused by a broken spring or bore wear.
- The new center support for the Ford A4LD will retrofit as long as the new selective No. 4 and No. 3 thrust bearings are used.
After rebuild, the vehicle has no converter clutch, stores trouble code 68 when driven in the Overdrive gear-selector position and stores trouble code 39 when driven in the D3 gear-selector position.
Many electrical and mechanical reasons can cause these codes to be stored. After all possible electrical reasons have been eliminated, the cause may be that the TCC enable valve in the pump cover has been installed backward.
Remove the pump assembly and install the TCC enable valve in the direction shown in Figure 1, and ensure free movement after installation.
Before or after overhaul, 1991-95 Cadillac Deville, Concours, Eldorado and Seville may exhibit a 3rd-gear start in the Drive position along with Diagnostic Trouble Code P040 (power-steering pressure-switch circuit open).
The cause may be a blown fuse in the circuit that supplies battery voltage to the solenoids in the transmission and the power-steering pressure switch.
In some model years the transmission solenoids, EGR solenoid, brake switch, canister-purge solenoid, power-steering pressure switch and air-conditioning relay are all on the same circuit. A short or wiring problem on any or all of them may cause the fuse to blow.
Locate terminal E on the harness connector, shown in Figure 2, and check for battery voltage with the ignition on.
If there is NO voltage at terminal E, see Figures 3 and 4 for fuse location and vehicle application, and replace the fuse.
The fuse in question is highlighted for identification purposes.
1993-up Saturns equipped with MP6 or MP7 automatic transaxles may exhibit delayed and/or harsh engagements into Reverse after the vehicle is at operating temperature. There also may be repeat failures of the external filter seal, which will cause fluid loss.
The cause may be:
- A broken cushion spring in the line-pressure regulator valve.
- Side-to-side wear in the pressure-regulator-valve bore.
Warm vehicle to operating temperature. Remove temperature sensor and install a 0- to 300-psi pressure gauge, as shown in Figure 5.
Remove 7.5-amp line-pressure-actuator fuse shown in Figure 6.
Place selector in Reverse at idle and ensure that line pressure is not less than 175 psi. If the pressure gauge indicates low pressure, remove the valve body and disassemble the pressure-regulator-valve lineup (See Figure 7a).
Locate the cushion spring in the line-pressure regulator valve and inspect it for breakage. If the spring is not broken, re-install the pressure-regulator valve, place a flashlight over the valve body as shown in Figure 7b, and look for light between the valve and its bore.
If you see light or the cushion spring is broken, replace the upper valve body with Saturn upper-valve-body kit, part No. 21005813.
- Saturn Upper-Valve-Body Kit…..21005813
Includes upper control valve body, both spacer-plate gaskets, valve-body cover gasket, spacer plate, and actuator-retainer exhaust diverter.
The part number for the late-model snap-design center support has been changed to OEM part No. F5TZ-7A130B, and the early non-snap-design center support no longer is available from Ford Motor Co.
Creates a common part that will retrofit to 1985. Parts Affected:
- No. 4 Thrust Washer – Was replaced by a new selective No. 4 thrust bearing, as shown in Figure 8.
The late-model snap-design center support will retrofit to early-design units as long as the new selective No. 4 and No. 3 thrust bearings are used (See Figures 8 and 9).
The No. 5 thrust bearing is not used on early non-snap-design models (See Figure 8).
- Center Support (Snap Design)……….F5TZ-7A130-B
- No. 3 Thrust Bearing ……………………..F3TZ-7L326-A
- No. 4 Thrust Bearing (Selective 0.110 in.) ………………..F3TZ-7L326-A
- No. 4 Thrust Bearing (Selective 0.120 in.) …………………F5TZ-7L326-A
- No. 4 Thrust Bearing (Selective 0.125 in.) …………………F5TZ-7L326-B
- No. 4 Thrust Bearing (Selective 0.130 in.)…………………F5TZ-7L326-C
If rear endplay is too tight with the thinnest of the four selective bearings, which is the F3TZ-7L326-A 0.110-in. thrust bearing, remove the No. 14 thrust washer, which is the steel shim on the rear of the sungear shell, and recheck the rear endplay. If end-play is now OK, leave out the No. 14 washer.
August 2001 Issue
Volume 18, No. 8
- THM 4L80-E/4L80-EHD: Trouble Code 68 in Overdrive Trouble Code 39 in Drive 3 All Electrical OK
- THM 4T60-E (Cadillac): 3rd-Gear Starts
- Saturn MP6/MP7: Delayed or Harsh Reverse Engagement
- Ford A4LD: Interchangeability of Center Support