TOPIC: Shift linkage cover

So what's the story behind drilling holes in this? Is it to get water into the housing to keep exhaust gases from eating the housing? If that's the case you wouldn't need to do this on the updated systems right? Just curious!

Good question.
Was to relieve exhaust gas pressure inside the leg, such that the water level would remain above the impeller, to keep the pump primed.
On the recirculating style cooling systems the pump would get water returned from the block in addition to pulling water up from inlet.
Was found that by drilling those holes the pump could stay primed especially while not underway.
However, I have seen a couple cases where the holes needed to be in there to keep an F model primed.
THere were plates with no holes, plates with 6 holes, plates with a big downward spout (all blue, sometimes on 85's).
So from my experience the general rule is the holes serve a purpose, best to have them.
Usually where you see this problem is running the motor in a barrel, the water needs to be up ABOVE the impeller. I get calls every year and guys will not have water flow and only have water up to the cavitation plate or barely above same.
And usually where you see problems are on the E model Gran Prix. Some of them don't have holes in the plate, and some of them had an extra drain tube from the manifold in addition to telltale hose.
Hope this helps.

Interesting. You bring up a good point for all outboards to make sure the pump is submerged not just the pickup. I understand what you are saying about priming the pump but I'm also wondering if a contributing problem to this being the drain holes getting plugged with sand and dirt. I've seen this on quite a few of mine. I've replaced the shift covers with the holes to ones without and haven't had any problems. This was after cleaning the drain holes in the gearcase.