Mueller Roll-Up Door L250 - Manual (Page 13)

WWW.MUeLLeRinC.CoM 13
step 13: aDJUst spRing tension
lOSS OF SPRINg
TENSION wIll CAUSE
DOOR CURTAIN TO
DROP RAPIDlY.
a Open door fully with the bottom bar resting against
the head stops.
B At dual tensioner end, place ½ inch ratchet into
tensioning hub and hold the ratchet firmly. Have
someone else loosen the square red headed 3/8
inch set screws on the dual tensioner and mounting
bracket.
C To increase spring tension, pull down on ratchet
1/4 turn. The dual tensioner will automatically
grip the axle and help hold the new tension setting.
Have someone else tighten all square red headed
3/8 inch set screws in dual tensioner and axle
support bracket at both ends of the door.
DOOR MUST BE IN FUllY OPEN POSITION TO ADJUST SPRINg.