MTU Input Queue Detent Mechanism Adjustment

Parts and Materials Required

  • Proper PPE
  • Standard screwdriver
  • Teflon-based grease
  • 13 mm combination wrench or a crescent wrench

Time Required

  • 15 minutes

Procedure

  1. Put on proper PPE.
  2. Before making any adjustments to the Input Queue mechanism, ensure that the spring plunger has been adequately lubricated. Lubrication of the detent system usually is sufficient to improve the drawer opening and closing action. Ideally, use a Teflon-based grease, although other greases may suffice; silicone grease has been found to be inadequate.
    1. Thoroughly lubricate all surfaces of the spring plunger.
    1. Open and close the drawer several times to test.
  3. ClosedFully open the Input Queue drawer. It is not necessary to remove any MTUs from the module.
  4. Open the right side access panel.
  5. Fully open the Universal Fluids Drawer.
  6. ClosedLocate the Input Queue spring plunger mechanism. Locate the thin 13 mm nut that fastens the spring plunger to the rest of the module.
  7. ClosedUsing a 13 mm combination wrench or crescent wrench, loosen the 13 mm nut.
    Caution—Do not loosen the nut more than 1/2 turn.
  8. ClosedWhile holding the 13 mm nut stationary, use a standard tip screwdriver from underneath the detent mechanism to adjust the height of the spring plunger. Turn the spring plunger counterclockwise to lower the height of the detent ball. Turn the spring plunger clockwise to raise the detent ball. Turn the plunger in increments of about 1/8 of a turn before testing.
  9. Tighten the 13 mm nut to lock the spring plunger at the new height.
  10. Apply grease to the adjusted detent mechanism.

Verification

  1. Open and close the Input Queue drawer repeatedly to check whether it is at the desired opening force.
    • The Input Queue drawer should be able to be opened using one finger. It should not be necessary to yank the drawer in order to open it.
    • The spring plunger should be high enough so that it engages with the detent recess in the drawer. When closed, the end of the drawer should be partially supported by the spring plunger ball.
  2. If necessary, repeat steps 6–8 to adjust the drawer opening force.