Blueband Merc 800 - Simple Gear Lube Questions

Replacing the gear lube, first time dealing with this old Merc - called local shop to verify how I'm replacing the lube... drained the old, then filling and draining to flush it, then filling again.

My understanding is to remove the Vent and the Fill plugs, fill until lube comes out the top (vent), close that off, then close off the fill.

This guy just told me I also have to open up the 'flush' plug, and after the vent is reached and capped, to keep adding fluid until it reaches the flush...????????? WTF is that true? I thought the flush was for flushing the motor with water - like if we took it through salt water... if someone could let me know I'd appreciate it.

One last thing - the shop gave us QuickSilver Premium (gold in color) but I now understand that what was in it must have been the high performance cuz it's blue - so that's why I'm flushing it out and filling a second time, I hope that's the right way to do it & that the premium will be OK for this motor??

Thanks

Re: Blueband Merc 800 - Simple Gear Lube Questions

You had it right till you mentioned the flush plug.

The flush plug has nothing to do with the oil, and is almost never used for flushing the cooling system.

Re: Blueband Merc 800 - Simple Gear Lube Questions

So bottom line is: leave the flush plug alone! - which was my intention until this yuck started talking about using it to cap off the oil - even *I* knew that didn't sound right!

If you have any thoughts on premium vs. high performance lube please feel free - I could always flush it out next time and go back to high performance on the next change if it would benefit this old beast....

Thanks!

Re: Blueband Merc 800 - Simple Gear Lube Questions

If I have a lower unit that leaks, gets changed often, or I don't really care about I use the cheap stuff.

But anything else gets the High performance Mercury stuff.