How to Fill an OMC Cobra & OMC / Volvo Cobra SX Outdrives with Gear Oil
How to Fill an OMC Cobra and OMC / Volvo Cobra SX Outdrives with Gear Oil.
Repair Time: 1 to 2 hours
Repair Difficulty: Easy
For this job, you will need:
- Oil pump
- 2 or more quarts of oil
- Large flathead screwdriver
- Rags
- Replacement oil draining screw gaskets
1. Place the Outdrive in a Vertical Position.
Start by tilting the outdrive vertically to drain the oil from top to bottom.
2. Locate the Lower Drain Plug on the Lower Gearcase.
(It is on the starboard side of the lower unit on the cone, as shown in the photo.)
Remove this drain plug using the largest flathead screwdriver available.
It is best to replace the drain plug gaskets: https://www.obparts.com/new-emp-volvo-penta-sx-drain-screw-gasket-oem-3852105/
3. Insert an Oil Pump as Snugly as Possible into the Drain Hole.
Use a universal gearcase oil pump like this: https://www.obparts.com/new-sierra-universal-oil-pump-18-9781/
3. Fill the Lower Gearcase with 80/90 Weight Gearcase Oil.
Fill the drive 80/90 weight gearcase lubricant. Begin pumping oil into the lower drain hole, and carefully watch the upper drain hole until you see the oil reach this level. When the oil reaches the upper drain hole, close it up by inserting the upper drain screw.
Fill the drive slowly to allow air to purge. Filling the drive too quickly may form air pockets, causing an inaccurate oil level reading.
Running a drive with an improper oil level will result in immediate internal damage.
Marine Parts Warehouse offers a high-quality outboard gear oil made by Volvo: https://www.obparts.com/new-oem-volvo-penta-80w-90-api-gl-5-outboard-gear-oil-part-1141676/
4. Locate the Upper Dip Stick Location.
(The upper dipsticks will look different on a Cobra SX, but the oil change process is the same.)
https://www.obparts.com/new-pro-marine-omc-cobra-1986-1993-3-0-5-8l-upper-sterndrive-top-cover/
On the top side of the upper gearcase is a cover with four large bolts. In the center of this cover or cap, you will see a 3/4" diameter flathead dipstick. Remove the cover and note the oil level.
The oil level on a Cobra should be at the dipstick's line.
Again, remove the drain screw from the upper portion of the lower gearcase, and quickly insert the oil pump into the upper drain hole.
Begin pumping oil to the proper level on the upper gearcase dip stick.
5. Frequently Check the Dip Stick Gauge While Filling.
When oil reaches level line, stop filling and screw in upper dipstick. This will create an airlock to prevent oil loss when installing the fill plug. Tighten the fill plug to a torque of 60-84 in-lbs. (7-9 N.m). Finish procedure by tightening the level indicator to a 10-12 ft—lbs torque. (14-16 N · m).
6. After the outdrive has been run, recheck the oil level.
After the outdrive has been run, recheck the oil level. Fill the drive-through upper dip stick opening to bring the oil up to the level line on the dip stick gauge.
Marine Parts Warehouse has a full selection of OMC Cobra replacement parts available here: https://www.obparts.com/omc-1/
We also proudly offer OEM & aftermarket replacement parts for Volvo SX drives: https://www.obparts.com/volvo-penta-2/
Posted by John McClane
