A/T - 4T60/3T40 Grinding/Growling On Incline

90pontiac25
Bulletin Number: 91-7-17
Reference Number: 077133R
Publish Date: 11/90
Subject: INFORMATION ON GRINDING/GROWLING NOISE IN PARK ON AN INCLINE

Models

Affected: 1980-91 6000, BONNEVILLE, SUNBIRD, GRAND AM, FIERO, LEMANS, GRAND PRIX, PHOENIX AND TRANS SPORT MODELS W/3T40 OR 4T60
Owners of some vehicles equipped with HYDRA-MATIC 3T40 and 4T60 transaxles may comment on a grinding and/or growling noise that is noticeable when standing in "Park" on a hill or slope with the engine running and the parking brake not applied. Under these conditions, the weight of the vehicle puts a load on the parking pawl which can create a "ground-out" path through the drive axles front struts, springs and spring towers. Normal engine noise can be transmitted to the passenger compartment through the "ground-out" path.

Owners concerned about this condition should be advised to apply the parking brake prior to shifting into "Park". This is the recommended procedure described in the owner's manual. Applying the parking brake first will put the load of the vehicle on the rear brakes rather than on the parking pawl.

Refer the owner to the appropriate owner's manual for additional details and instructions.