Driveshaft Pinion Bearing Inspection; Upper Driveshaft Bearing Inspection - Mercury 25 EFI Service Manual

Gear Housing
7. Inspect the area of the propeller shaft where the forward gear bushing contacts to determine the condition of the forward
gear bushing. Replace the propeller shaft and forward gear assembly if the surface is discolored from lack of lubricant,
pitted, or worn.

Driveshaft Pinion Bearing Inspection

IMPORTANT: Do not remove the lower driveshaft pinion bearing from the gearcase unless replacement is necessary. The
removal process may damage the bearing.
1. Inspect the pinion bearing surface on the driveshaft. Replace the driveshaft and the pinion bearing if it is pitted, grooved,
scored, worn unevenly, discolored from overheating, or has embedded particles.
a
2. Use the Bearing Installation Tool to remove the pinion bearing.
Bearing Installation Tool
IMPORTANT: The gear housing must be replaced if the forward gear tapered bearing race, upper driveshaft bearing, or pinion
bearing appear to be spinning in their respective bores.

Upper Driveshaft Bearing Inspection

IMPORTANT: Do not remove the upper driveshaft tapered bearing from the driveshaft unless replacement is necessary. The
removal process may damage the bearing.
1. Inspect the upper driveshaft tapered bearing for rust, roughness, or excessive wear.
Page 6A-26
a
a -
17009
b
a
c
b
g
© 2016 Mercury Marine
Forward gear bushing surface
a - Pinion bearing surface
b - Oil slinger spring
17010
a - Puller shaft
b - Nut (part of Bearing Installation Tool)
c - Washer (part of Bearing Installation Tool)
d - Flange (part of Bearing Installation Tool)
d
e - Guide
f - Pinion bearing
g - Retainer (part of Bearing Installation Tool)
e
f
16251
91‑895195001
90-8M0105568 eng MARCH 2016