New Parts: Gears (drive / driven), water pump shaft / drive shaft and 4 Bearings
Oil seals, o-rings and gaskets and
water pump assembly (impeller housing and impeller)
Ball gear, plug, shims and nut. For a complete list of new parts
installed, please see: OMC 800 outdrive rebuild page
Machined parts: Pinion drive shaft*
*If drive shaft groves from seal wear requires machining of more
than .010 of an inch or water pump shaft splines male or female are more than 20% worn, new shafts will be installed into
the upper housing
Upper gearcase gears
Different size engines require different gear ratios in the drive.
The manufacturer changes these ratios with different gear sets.
The ratio change is in the upper housing. All
1973 - 1985 upper housings are identical* except for the tooth count on the gears and left or right steering worm.
Below is a chart showing the tooth count for the different size engines used with sterndrives.
All lower housing
ratios are either 2.0:1 for the four-cylinder engines or 1.83:1 for the six,, and eight-cylinder engines. *The original driven
gears in 1970 - 1974 upper housings are not machined for a centering cone.
All 1975 and newer driven gears and
all GLM replacement driven gears are machine for a centering cone.
A new drive shaft with shorter splines and
a centering cone must be installed when replacing the original (non-centering cone) driven gear.
Low profile case
Gear Ratio
Left hand steering
Right hand steering
4 Cylinder engines with 120 hp. Years 1970 to 1977 will have used set installed in rebuild units
16 / 20
Call to order
4 Cylinder engines with 140 hp. Years 1970 to 1977 will have used set installed in rebuild units
19 / 20
Call to order
4 cylinder engines 1978 and up $1699.89 *after trade in
21/ 18
P/N 27500R OEM 982486
4 cylinder engines 1978 and up $1699.89 with used gears *after trade in
21/ 18
P/N 27500U OEM 982486
3.8 Liter 229 cubic inch V6 $1645.95 *after trade in
21 / 20
P/N 27400R OEM 982739
3.8 Liter 229 cubic inch V6 $1699.89 with used gears *after trade in
21 / 20
P/N 27400U OEM 982739
165 to 190 hp. with inline 6-cylinder years 1972 to 1977 and 4.3 Litre 262/264 cubic inch V6 $1655.95
21/ 19
P/N 27300R OEM 981229
165 to 190 hp. with inline 6-cylinder years 1972 to 1977 and 4.3 Litre 262/264 cubic inch V6 $1699.89
with used gears
21/ 19
P/N 27300U OEM 981229
5.0 Liter 302 Ford or 305 Chevy V8 $1699.89*after trade in
21/17
P/N 27200R OEM 982487
5.0 Liter 302 Ford or 305 Chevy V8 *after trade in $1699.89 with used gears
21 / 17
P/N 27100U OEM 982488
5.7 liter 350 Chevy V8 and 5.8 liter 351 Ford V8 $1699.89 *after trade in
21 / 16
P/N 27100R OEM 982488
5.7 liter 350 Chevy V8 & 5.8 liter 351 Ford *after trade in $1699.89 with used gears
21 / 16
P/N 27100U OEM 982488
High profile case
Rebuilt high profile upper case $1699.09 *after trade in
