NOTE: A light coating of vaseline on clay surface will prevent clay
____
pickup on moving parts.
(8)
Check for latches being out of time with handle cam. When closing door, door body should drop back in 0.015 inch as latches go 10 degrees overcenter. Gates should just stop and not go back in. Check alignment of push rod and crank that operates gate when door is closed. These should have dead center alignment with latching torque tube with door closed.
(9)
Snubber may be bottoming out. Check travel of snubber piston.
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737-300/400/500MAINTENANCE MANUAL
(10) Binding of guide arm in guide cams at upper hinge may be due to misaligned cam plates. Check by moving guide arm (one end removed from door) through cams and check for alignment of guide arm with centerline of hinge plane. Misaligned cam plates can cause guide arm to work hard on one cam plate and force cam plate to come loose. Cam plates may be aligned but rotated. This will cause door to have extra travel in either cocked position or open position. It may not cause handle loads to be high.
NOTE: Misaligned guide cams would probably only occur after cam
____ replacement due to tolerances in cam installation boltholes.
E. Excessive torque problems (Ref 52-41-00, A/T, for door operating torque limits).
(1)
Operate door and check for interference with body structure. Look for scraped paint as an indication. To verify, place a strip of paper over suspected area and close door. Paper should pull out without tearing.
(2)
Check seal plane for smoothness and excessive buildup.
(3)
Check stop gaps. If there is evidence of excessive bottomong out, adjust. Also check gate stops.
(4)
Make sure the bearings in the upper and lower gate pushrods move freely.
(a)
Lubricate the bearings if they cannot move (AMM 12-25-41/301).
(5)
Check snubber for bottoming out.
(6)
Check for door entering opening evenly at forward and aft latches during last inch of travel. Adjust guide arm if required.
(7)
Check misfair. If a latch cam can be moved inboard without exceeding misfair tolerances, torque can be reduced. Stops must be reset if adjustment is made. Also, shortening gate control rods will reduce torque.
(8)
Check for latch cam rollers entering latch cams before roller arms begin to rotate. Adjustment to horizontal control rod at handle cam can reduce torque. Check exterior handle stowage force.
(9)
If lining is installed, check for interference of lining and body structure or trim. Check with a strip of paper as in step (1).
(10)
Check for smooth operation, without jerks or bumps, at handle cam. High spot in cam can cause excessive torque.
(11)
Check for clearance between latch cam rollers and outboard face of cam. Throughout operation of normally operating door, roller should not touch outboard face of cam. This contact can cause high torque.
F.
Check for excessive misfair (Ref 52-41-00, A/T for allowable misfair).
(1)
Excessive misfair will often result from adjustments to lower torque tube. If adjustments to latch cams or gate rods to improve fair result in excessive torque, trouble shoot per step A.
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ALL ú ú B02 Page 102 ú Jul 12/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
737-300/400/500MAINTENANCE MANUAL
G. Trouble shoot problem of door handle not staying latched in flight or handle moves during taxi:
(1)
Check for clearance between latch roller and bottom of latch cam. Improper clearance indicates door overcenter out of adjustment. Adjust for soft unlatching per 52-41-00, A/T.
H.
Trouble shoot excessive handle stowage force (Ref 52-41-00, A/T for allowable handle stowage force):
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