Instructions / Assembly

ManualsBrandsChamberlain ManualsDoors & WindowsHeavy Duty Chain Drive Rail Extension Kit for 10 ft. Garage Doors

To avoid possible SERIOUS INJURY from a falling garage door opener,

fasten it SECURELY to structural supports of the garage. Concrete

anchors MUST be used if installing any brackets into masonry.

ADD AN ADDITIONAL SUPPORT BRACKET:

Cut the enclosed support bracket to fit across the installed support

brackets. Fasten the cross brace to the top and bottom hole of the support

brackets using 5/16" -18x7/8" hex bolts, 5/16" lock washers and 5/16" -18

nuts.

IF THIS IS AN EXISTING INSTALLATION (CONTINUED):

9. Install idler pulley assembly (Figure 7).

10. As a temporary stop, insert a screwdriver into the hole near the rail

tab. Slide the trolley to this point.

11. Use a flathead screwdriver to lift the rail tab until the tab is vertical (90°)

(Figure 8).

12. Pull the chain around the idler pulley. Connect the chain to the

retaining slot on the trolley with master link, as shown.

13. With the trolley against the screwdriver, pull the chain along the rail

toward the motor unit around the sprocket to the trolley assembly. The

sprocket teeth must engage the chain (Figure 9).

14. Connect the chain extension piece to the full chain with the master link.

15. Check to make sure the chain is not twisted, then connect it to the

threaded shaft with master link.

16. Insert the trolley threaded shaft through the hole in the trolley. Be sure

the chain is not twisted. Loosely thread the outer nut onto the trolley

threaded shaft. Remove the screwdriver.

17. Tighten the outer nut until the chain is approximately 1/4" (6 mm)

above the base of the rail at it's midpoint. Tighten the inner nut to

secure the adjustment (Figure 10).

18. Replace the old emergency release rope with the new, longer

replacement rope using overhand knots.

19. Refer to Installation Step 5 in your owner’s manual to complete the

re-installation and adjustment of your garage door opener. NOTE: After

hanging the opener, add the additional support bracket for stability.

See Add An Additional Support Bracket below.

20. Reconnect door control and sensor wires.

21. Reconnect power.

22. Program travel limits and test the safety reversal system according to

the owner's manual.

Lock Washer 5/16"

Nut 5/16"-18

Lock Washer 5/16"

Nut 5/16"-18

Hex Bolt 5/16"-18x7/8"

Support Bracket

Trolley

Threaded

Shaft

Outer Nut

Retaining Slot

Chain Extension

Piece

Idler Pulley

Master Link

Trolley

Rail Tab

Master Link

Inner nut

Mid length of RailBase of Rail

Chain

1/4" (6 mm)

Figure 7

Figure 8

Figure 9

Figure 10

REPLACEMENT PARTS

Part No. Description

041B1986-10 Ten-Foot Chain

41A3021 Emergency Release Rope

4A1008 Master Links (2)