SUBJECT: Modification of gearcase #378611;
35 h.p. RDS(L)-20 thru RD(SL)-21 series.
40 h.p. RD(SL)-22 thru RD(SL)-24 series.
Figure 1 illustrates a slight change made to gearcase 378611 used on the subject engines. The spray plate has been lowered slightly, arrow "A", figure 1, on the new style unit which in turn requires a longer screw to insure adequate thread engagement. Six of these long screws, part #309244, are included with each new style gearcase and will be automatically shipped with each order.
Although the gearcase has been modified, the part number remains unchanged. To assist in identifying the new style from the old, note that the new unit can be identified by the cast letter "Z" while the old unit contains the cast letter "T", figure 2.
This change does not affect interchangeability of the two gearcases except that the old, short screw, part #308429, MUST NOT BE used under any circumstances, with new style gearcase "Z". The longer screw, part #309244, MUST be used with gearcase "Z", and may also be used with gearcase "T". Use the old style gearcase until distributors' stocks are exhausted.
Service Department
WWD:eb
NOTE: Post on your RD indexes (35 & 40 h.p.).