Shaft-Transmission Alignment; Checking Alignment; Shaft Log Stuffing Box Packing - Bayliner 3388 Owner's Manual Supplement

14 CHAPTER 3: COMPONENTS / SYSTEMS

Shaft-Transmission Alignment

• Alignment between the engine transmission output shaft
and the propeller shaft is critical. This alignment has
been performed at the factory, and was rechecked by the
dealer after the boat had been in the water for 48 hours.
• An alignment inspection should be performed as part of
the routine maintenance program (after the initial 30
hours of operation, then every 60 hours) and whenever
unusual noise or vibration is noticed.
• To insure proper alignment after a hallout or dry storage,
wait 48 hours after launching before making final align-
ment adjustments.

Checking Alignment

Engine alignment requires moving the engine and should be
performed by a marine mechanic. However, checking the
alignment is relatively simple when these steps are followed:
1. Remove the flange bolts at the transmission-to-shaft
coupling and slide the shaft aft until the flanges are about
1/4" apart.
2. Rotate the shaft to see if there is obvious "wobble" of the
shaft flange. If there is, it may indicate that the shaft has
been damaged and should be inspected by a marine
mechanic as soon as possible.
3. Move the shaft up and down and from side to side to
determine, as closely as possible, the central position
where the shaft is normally located. At this position, the
transmission flange should align with the shaft flange without moving the shaft more than 1/8". If this is not the
case, a misalignment condition exists.
4. Move the shaft flange into contact with the transmission flange.
5. Check the gap between flange faces by attempting to insert a 0.003" feeler gauge at the top, bottom and each side.
6. Repeat this operation after rotating the shaft flange 1/4 turn (3 times). If the feeler gauge can be easily inserted at
any point, a misalignment condition exists.
If a shaft misalignment exists, have a qualified marine mechanic per-
form an alignment as soon as possible. Continued use may lead to pre-
mature engine, transmission, shaft, shaft seal and/or hull damage.
7. Reinstall the flange bolts, nuts and lock washers (if provided) and torque
to the specifications listed to the right. Replacement bolts, nuts and wash-
ers must be corrosion resistant and grade 8 or better.

Shaft Log Stuffing Box Packing

The propeller shaft emerges from the bottom of the yacht through an opening called the shaft log. The shaft stuffing
box is connected to the shaft log by a short length of special flexible hose. Packing rings are compressed around the
shaft by the packing gland. The stuffing for the box prevents excessive amounts of water from leaking around the
shaft and into the boat. Normal wear can cause stuffing box leakage to increase. Excessive leakage can usually be
stopped by tightening the packing gland nuts slightly. DO NOT over tighten the packing gland nuts. A slight leak (up
to 10 drops per minute while running) is normal and helps lubricate the packing and is therefore NECESSARY.
When stuffing box leakage becomes excessive, even after following the above steps, packing replacement can be per-
formed as follows;
1. Remove the yacht from water.
2. Loosen the packing gland nuts and back the packing gland from the sleeve. Remove the old packing.
3388 Motoryacht • Owner's Manual Supplement
CAUTION
!
TYPICAL TRANSMISSION-TO-PROP SHAFT COMPONENTS
TRANSMISSION-TO-PROP SHAFT COMPONENTS
NOTE:
VARY DEPENDING ON ENGINE TYPE AND SIZE.
BOLT SIZE
3/8" - 24
7/16" - 20
1/2" - 20
5/8" - 18
M16 x 1.5
TORQUE
40 +/- 7 lbs.
65 +/- 10 lbs.
95 +/- 15 lbs
200 +/- 30 lbs
175 +/- 25 lbs