Volvo Penta AQUAMATIC 280 Workshop Manual page 41

Repair instructions
NOTE! When calculating the shim thickness for the
forward and reverse gears, remember:
The upper gear housing nominal dimension has
two values.
If the stamped number is 50 or more, use the lower
nominal value, 61.00 mm.
If the stamped number is 49 or less, use the higher
nominal value, 62.00 mm.
Example:
"C" stamping: 78
Use Nominal Dimension = 61.00 mm
Example:
"C" stamping: 43
Use Nominal Dimension = 62.00 mm
Then follow the procedure in chapter Checking the
gear backlash and contact pattern .
Method 2
1
12. Insert a 0.2 mm (0.008") shim (1) under both for-
ward and reverse gears as a starting point. The shim
value is a number derived from experience.
Then follow the procedure in chapter Checking the
gear backlash and contact pattern .
38
Stamping 50 or more
= 00.78 mm
61.78 mm
Stamping 49 or less
= 00.43 mm
62.43 mm
Checking the gear backlash and
contact pattern
13. Install the forward gear with the calculated shims
into the gear housing. Insert the needle bearings and
the vertical shaft. Install reverse gear into the gear
housing using the needle bearings as a guide.
14. Install the washer (2) and the split locking ring (1)
and tighten the nut at the opposite end of the vertical
shaft.
1
2