1976 - 1977 Corvette: Service Bulletin: Thawing Frozen Door Locks and Preventing Future Freezing

Subject:   Thawing Frozen Door Locks and Preventing Future Freezing
Model and Year:   1976 - 1977 Passenger Models
Source:  Chevrolet Dealer Service Technical Bulletin
Bulletin No:   77-T-58
Section:   I
Date:    Dec., 1977

TO:  ALL CHEVROLET DEALERS

This bulletin is being reissued to correct bulletin number from 77-I-63 to 77-T-58.  Please destroy previous copies of bulletin 77-I-63 with subject indicated above.

A temporary condition may exist on some of the above models as a result of washing the vehicles in extremely cold weather (near or below 0° F) whereby it could be difficult to unlock the front doors; or if opened and equipped with electric door locks, it may be difficult to latch beyond the secondary latch position.

If experienced, the following procedure applied to the door lock system (after opening and thawing) should prevent recurrence of the subject condition.

1. If door cannot be opened, heat lock and lock cylinder area with heat guy; or pour luck-warm water into lock area of door thru door outer belt sealing strip.
2. Lubricate lock cylinder(s) with a liberal application of WD-40 Spray Lubricant or 3M "4-Way" Spray #8902.
3. Prepare a slurry (Solution) of lock lubricant; mixing one part of Lubriplate Autolube "A" lubricant, GM P/N 1052196 (14-ounce can) to 1 to 1-1/2 parts oleum solvent.  Mix a sufficient quantity of this solution to completely submerge lock.
   
   NOTE : Slurry must have a runny or "soupy consistency to penetrate and lubricate all lock components.
4. Remove affected door lock(s) from door as described in Fisher Body Service Manual, then immerse lock in lubrication slurry for approximately 5 minutes.
5. Drain lock of excess lubricant and reinstall into door.
6. If unit is equipped with power door lock system using solenoid actuator as shown in Figure #1 (all 1976 styles and 1977 "f" and "X" styles), inspect rubber boot at top of solenoid for tears or cuts.  If boot is intact, lubricate solenoid shaft with lock lubricant slurry.  Take care not to damage solenoid boot during removal for inspection and shaft lubrication.
   
   NOTE: Do not lubricate solenoid below boot area of solenoid shaft.
   
7. Reinstall all previously removed components and trim, then check lock cylinder, solenoid and lock assembly for proper operation.

Recommend .3 hour to make slurry and lubricate parts. Use published times for door lock and/or actuator R & R.