Chamberlain 8587W Manual page 8

Assembly
2 Attach the Chassis Support Bracket
To avoid possible SERIOUS INJURY to finger from moving garage door opener:
• ALWAYS keep hand clear of sprocket while operating opener.
• Securely attach sprocket cover BEFORE operating.
1. Position the chassis support bracket on the unit.
2. Attach the bracket to the rail with 1/4"-20 x 5/8" hex bolts and lock washers. Do not
overtighten.
3. Attach the bracket to the opener by inserting a 5/16"-18 x 1/2" washered screw through a
hole in each side flange and a matching hole in the bracket. Complete the connection by
inserting the #8-32 x 3/8" screw through the back flange and the hole in rail support.
Hex Bolt
Lock
1/4"-20x5/8"
Washer
Screw
#8-32x3/8"
Washerd Bolt
5/16"-18x1/2"
3 Tighten the Chain
1. Loosen the inner nut and lock washer on the trolley threaded shaft.
2. Tighten the outer nut until the chain is a 1/2" above the base of the rail at the midpoint
of the rail.
3. Re-tighten the inner nut.
Slack in the chain is normal when the door is closed. No readjustment is necessary.
Sprocket noise can result if the chain is too loose. During future maintenance, ALWAYS pull the
emergency release handle to disconnect the trolley before adjusting the chain.
Sprocket noise can result if the chain is too loose. During future maintenance, ALWAYS pull the
emergency release handle to disconnect the trolley before adjusting the chain.
8
1/2" (13 mm)