Inspect the propeller shaft for correct phasing. Correct
phasing means that the front and the rear U-Joint are directly in line or
parallel with each other so that proper cancellation takes place.
One Piece Propeller Shaft Phasing Inspection
- Rotate the propeller shaft
so that the propeller shaft rear U-Joint bearing cap is vertical.
- Inspect the front propeller
shaft bearing cap to ensure that it is also vertical.
- Place the inclinometer on the propeller shaft rear U-Joint bearing
cap, installing it 90 degrees (perpendicular) in relation to the propeller
shaft.
- Set the indicator line above the sight glass on 15 (the horizontal
reference). Rotate the propeller shaft until the bubble centers in the sight
glass. This action brings the rear Joint to vertical.
- Remove the inclinometer without disturbing the prop shaft. Leave
the setting on 15.
- Install the inclinometer on the front Joint. The bubble should
remain centered plus or minus 3 degrees if the shaft is properly phased.
The out of phasing of the single-piece propeller shaft is very unusual.
If the shaft is visibly out of place, the end yokes are welded on in the wrong
position or the shaft is damaged due to twisting. In either case, replace
the propeller shaft before continuing with this procedure.
Multiple-Piece Propeller Shaft Phasing
The setup and measurement techniques are identical to that of a the
one-piece propeller shaft system. First, check for proper phasing, using the
following procedure:
- Turn the rear propeller
shaft so that the rear Joint is straight up and down. Verify that the front
Joint of the rear propeller shaft is also straight up and down.
- Rotate the shafts 90 degrees so that the front propeller
shaft front Joint is straight up and down. Ensure that the front propeller
shaft is also straight up and down (actually part of the slip yoke on the
rear shaft).
If the 2 U-Joints of the front propeller shaft are not in this phase,
the 2 halves of the propeller shaft may have been assembled incorrectly.