(c)
Put the .500 x 20 jam nut on the cam axle shaft.

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A 737-300/400/500MAINTENANCE MANUAL
 (d)  Tighten the jam nut until it is against the nut that is already on the cam axle shaft.
 NOTE: If you use two jam nuts, align the flats on the
____ nuts and put small washers between them to make sure a wrench will not slip.
 WARNING:_______HOLD THE WRENCH SECURELY. IF THE WRENCH SLIPS IT CAN CAUSE DAMAGE TO EQUIPMENT OR INJURY TO PERSONS.
 (e)  Use a wrench on the jam nuts to turn the cam axle shaft clockwise 90 degrees. Hold it in this position.
 NOTE: This compresses the springs in the counterbalance
____ mechanism. This will make the guide pin extend out of the adjustment fitting.
 (f)  
Remove the sleeve from the guide pin.

 NOTE: There may not be a sleeve on all guide pins.

 (g)  
Put the nut and washer on the guide pin until they touch the adjustment fitting.

 NOTE: This will keep the counterbalance springs compressed
____
 when you release the wrench.

 (h)  
Slowly release the cam axle.

 (i)  
Turn the cam axle again to compress the counterbalance springs until it is possible to remove the counterbalance mounting bolt that is under the springs.

 (j)  
Move the nut and washer on the guide pin until they touch the adjustment fitting.

 (k)  
Slowly release the cam axle again.

 (l)  
Remove the five bolts that hold the counterbalance to the door.

 (m)  
Remove the counterbalance from the door.

 (n)  
Remove the screw, washer and clip from the cable drum.

 (o)  
Remove the broken cable from the counterbalance and the door.

 (p)  
Replace the bearing in the idler before you install the counterbalance again. 1) Remove the twelve bolts that hold the sides of the

 counterbalance to the block. 2) Remove the bolt that is the pivot for the idler link. 3) Remove the spring cartridge and the idler link from the
 counterbalance.
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737-300/400/500MAINTENANCE MANUAL
 4) Replace the idler bearing.
 5) Install the spring cartridge in the counterbalance.
 6) Install the bolt that is the pivot for the idler link.
 7) Install the twelve bolts that hold the sides of the

 counterbalance to the block.
 S 428-003-B00
 (3)  Do the task that installs the counterbalance on the door (AMM 52-31-12/401).
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A 737-300/400/500MAINTENANCE MANUAL
PULLEY
COUNTERBALANCE ASSEMBLY
SEE A
IDLER LINK PIVOT
CAM AXLE
SHAFT

CABLE DRUM  BLOCK 
WASHER SLEEVE GUIDE PIN 
FITTING ADJUSTMENT  SCREW 
CARGO DOOR 
1  SOME AIRPLANES DO NOT HAVE SLEEVE, SCREW AND WASHER ON GUIDE PIN.  COUNTERBALANCE ASSEMBLY A 1 
Figure 801 Cargo Compartment Door Balance Mechanism

 E30371
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