Thrust Bearing and Shim Replacement - SB-764

February 11, 1960. Upper gearcase pinion bearing and shim service for Johnson 50 and 75 HP engines.

Service Bulletin

DEALER
SERVICE MGR.
SALES MGR.
PARTS MGR.
SERVICE MGR.
February 11, 1960Bulletin No. SB-764

Subject: THRUST BEARING AND SHIM REPLACEMENT - UPPER GEARCASE, 50 and 75 H.P.

Original factory Figures 1 and 2: 75 HP and 50 HP upper gearcase exploded views identifying thrust bearing and shim locations

When replacing pinion bearing and shim sets, be sure not to lose the shim as it has been gaged to close tolerances with the bearing. The shim which comes with the bearing, or one of exactly the same size, must be used. If too thick a shim is installed, the pinion gear will mesh too tightly with forward and reverse gears which can result in noisy gears. Conversely, if too thin a shim is used, the pinion gear will not mesh sufficiently which causes excessive backlash. Either condition results in premature wear of the gears and is to be avoided.

If a new shim is necessary because of slight damage or other reason, use a micrometer to measure the thickness of the old shim and order a new one of exactly the same size from the following lists. Order according to horsepower and engine model.

75 H.P.

.002"307104
.003"307105
.004"307106
.005"307107
.006"307108

50 H.P.
V4 & V4S-10 and 11 / V4 & V4S-11B

.006"305162 / 306287
.008"305163 / 306288
.010"305164 / 306289
.012"305165 / 306290
.0135"305166 / 306291
.015"305167 / 306292

If the shim is inadvertently lost, a new bearing and shim set must be ordered and installed. Again order according to horsepower and engine model, as follows:

75 H.P. - #377887 Bearing and Shim Assy. (Fig. 1)

Over

- 2 -

Original factory Figure 3: 75 HP pinion thrust bearing with Thrust Here marking and arrow

Fig. 3
Pinion Thrust Bearing - 75 H.P.

50 H.P. - (See also Service Bulletin No. SB-717 dated 5/5/59.)

V4, V4L, V4S, & V4SL-10, 10H & 11: order #377138 Bearing and Shim Assy. (Fig. 2)

V4, V4L, V4S, & V4SL-11B order #377658 Bearing and Shim Assy. (Fig. 2)

When the thrust bearing is pressed into place on the 75 H.P. gearcase, be certain the face containing the words "Thrust Here" is down! (See arrow, Fig. 3).

Also, on the 75 H.P. engines, be sure the flat face of tru-arc retaining ring, part #307081, is toward the thrust bearing.

JOHNSON MOTORS
W. W. DeWees
W. W. DeWees
Service Department

WWD:eb

NOTE: Post on V4 Series Index.

Related bulletin: SB-717 - Pinion thrust bearing and shim service.