M/T - New Synchromesh Parts

87saab02

FILE IN S.I. VOL. Man I

SEC. A-4 PG. 102

Service Information

SUBJECT: NEW SYNCHROMESH PARTS FOR ISSUE: 12/87-1016
5-SPEED GEARBOXES SUPERSEDES: 04/83-622


APPLICATION: 900 MODELS



Running changes were made to gearboxes during 1983 model production which affect replacement parts for all early 5-speed gearboxes. From gearbox number 480053 and 523814 a new synchromesh design was introduced to improve shift quality. This Service Information identifies the new design and corrects a part number error from S.I. 04/83-622.

See the footnotes below. Old-design synchromesh sleeves are no longer available for older gearboxes. If a newer style sleeve must be used, a multiple supersession has been created to supply the proper accompanying parts. Do not install old design parts into gearboxes built after the gearbox numbers given above.
* Part number correction. ** No longer available. Use new-design synchro sleeve and new-design synchro rings together (see parts system multiple supersession MS221). *** No longer available. Use new design gears which are compatible with old-design synchro rings and sleeves.

Note: Old design synchro rings are still available for repairs where the old-design synchro sleeve may be re-used.

FIGURE 1 - SYNCHROMESH COMPONENTS CROSS SECTION.:

FIGURE 2 - SQUARES (THREE PAIRS). INDICATES TAPER ANGLE OF 6~. SEE ITEM 1.:

Parts Identification:

To prevent confusion between old and new parts, six squares (three pairs) have been provided on the inside surface of the new synchromesh rings and a groove has been turned on the outside circumference of the sleeves. The difference between the old and the new gearwheels may be seen clearly by the asymmetrical tips on the new engagement teeth (Figure 1).


NOTE

Synchromesh sleeve 87-20-419 must always be installed with two synchromesh rings of the new design (87-19-916 and 87-19-924) and vice versa.
Turned groove Taper angle Synchromesh sleeve Synchromesh ring
Gearwheel Symmetrical Tip angle Asymmetrical