A 1984 through 1987 vehicle equipped with a THM 440-T4 transaxle may have an intermittent no reverse or locking in reverse condition un-til shifted to a forward range prior to shifting into reverse (“un-loading” the parking pawl). This condition may be caused by a “dent” on the parking paw1 that does not allow the paw1 to release until “un-loaded”. You can get more obd code scanners for help.
Date of Production Change: (Figure 1)
Effective May 1, 1987 (Julian Date 121) all 1987 THM 440-T4 transaxles were produced with parking paw1 assemblies not having a “dent”.
Service Action: (Figures 2 and 3)
If this condition is encountered, remove transaxle and replace the final drive internal gear/parking paw1 assembly (No. 673) and actuator guide, plunger and spring assembly (No. 709 – No. 711). Also inspect the parking gear for wear or damage and replace if necessary.
Service Parts Information:
Part Number Description
8656372 Final Drive Internal Gear/Parking Paw1 Assembly
8656689 Actuator Guide, Plunger and Spring Assembly
8644238 Parking Gear
Service Notes: (Figure 2)
Before installing the replacement parts , inspect the new final drive internal gear/parking paw1 assembly to make sure it does not have a “dent”. Some hot car tools like Launch CR-HD and SKT100 may bring you more information.