38415A.S - Chain Sprocket Installation Instructions
Chain Drive Sprocket 38415A.S Replacement
BE SURE ELECTRICAL POWER HAS BEEN DISCONNECTED FROM THE INPUT POWER LINES PRIOR TO REMOVING THE MOTOR COVER.
ANY AND ALL REPAIRS MADE TO THIS UNIT MUST BE PERFORMED WITH THE DOOR DISCONNECTED FROM THE OPENER AND IN THE CLOSED POSITION.
1. Pull emergency release cord on the carriage to disengage opener to close the door if necessary. (If unable to lower door using an opener, use extreme caution manually closing the door. Before pulling the emergency release cord, make certain people and objects are clear of the door opening.)
2. Unplug the garage door opener power cord from power receptacle.
3. Open lens cover by pressing outer tabs on both sides of the motor and swing down to remove light bulbs. FIG. 1.
4. Remove wall control and Safe-T-Beam wires from the terminal block located on the rear of opener FIG. 1A. Use a small common screwdriver to press in on orange tabs while gently pulling wires from the block. Mark wires to help facilitate replacement.
5. Remove the cotter pin & clevis from door arm to separate door from the opener. FIG. 2.
6. Remove motor head and rail assembly from mounting brackets/hardware and set on a clean work surface or floor.
7. Remove the 3-5/16” bolts from rail to motor mount to remove the chain rail. FIG. 3.
8. Loosen 1/2” tension nut at header end of the rail to create slack in the chain/belt. FIG. 4.
9. Place scrap block of wood under the sprocket assembly and drill out the rivets holding the sprocket bracket to the rail with a #7 (.201) drill bit.
10. Remove screws from upper and lower brackets to separate the sprocket bracket assembly and remove the old sprocket.
11. Install replacement chain sprocket 38415A.S, with bushing to lower bracket.
12. Wrap chain/belt around the new sprocket.
13. Install sprocket guard and reinstall lower bracket screws.
14. Align bushing into the upper bracket and assemble over the sprocket.
15. Reinstall screws into sprocket guard through upper bracket.
16. Use the supplied nuts and bolts to fasten bracket assembly to the rail.
17. Tension the chain/belt with the 1/2” tension nut. FIG. 4.
NOTE: Refer to the manual for proper tension. (1/8” gap between chain/belt and rail)
18. Assemble rail to the motor head. FIG. 3.
19. Install operator to mounting hardware. Refer to owners manual for reassembly if necessary.
20. Reinstall wall control and photocell wires. FIG. 1.
21. Reinstall Light Bulbs and close lens cover(s) and rear cover. FIG. 1.
22. Reattach door arm to the carriage with clevis and hairpin. FIG. 2.
23. Move door up or down to reengage carriage into chain/belt.
24. Refer to owners manual to reset up and down limits.
25. Perform complete safety check per owners manual.