Vertical Drive Maintenance

[Newby]

I have a Cobra outdrive unit and want to do my own maintenance on the gimbal bearing and universal joints. Does anyone have experience in removing and reinstalling the vertical drive unit after lubricating these components? Is there a gasket involved? Special Tools? I'm told this maintenance should be done every 50 hrs or so, especially if the boat is used to troll as the lubrication will work its way out of the spline shaft. Any advice would be helpful/appreciated.

[perchjerker]

I have done volvo pentas and merc's, but not omc. I beleive its very similar to the merc setup. If so, you will need an alignment tool to make sure the outdrive is lined up properly to the engine, otherwise, you will ruin the gimbal bearing. What it looks like is a dummy driveshaft. Do yourself a favor, get a manual for this unit. Its worth the investment. Another thing. older OMC's were known to have problems with the shift cable stretching, causing the clutch dog to were prematurely, and the drive pops out of gear under load. Something to do with when the drive tilted, it streched the cable, if memory serves me. Dont know if that applies in your case, though.

[Gary B]

I highly recommend that you get a manual. If nothing else, Clymers manuals are available through many sources for approx $25-30. I know that on my '95 Cobra/Volvo drive there is one specially formed "O"-ring that is usually re-usable. Do yourself a favor and get some type of hoist or stand to lift and support the drive. It will probably weigh 70-100 lbs, and you don't want to wrestle it on and off. Besides, you need a way to support it while you have it off. I made a little wood stand with four casters that supports the drive by slipping under its anti ventilation plate. Removal is the only way to grease the u-joints. Most manufacturers recommend this annually. Get or make an alignment tool to check engine position. It is not a difficult job. Just follow the book and be careful. Good luck.

[Newby]

Thanks for the advice Gary B.
I got a manual covering the unit (1989 OMC Cobra), but I don't recall reading about an alignment tool. What does the alignment tool look like and how do you use it?

[Gary B]

The Manual should address this. The alignment tool goes through the gimbal bearing into the drive coupling to see if the engine is lined up with the gimbal bearing. Misalignment can cause noise and excess wear, even premature failure. This can only be checked when the drive is removed.