while re-rigging my 98 253 checkmate, noticed my merc drive tank was full of green sludge !!! just wondering if anybody else seen this ??

I've owned 4 boats and on every one I had to occasionally remove the drive fluid reservoir and clean the sludge out of the bottom of it.

I found the same problem when a drive lost the bottom oil fill screw......the drive bottle still showed 1/2 full. Turns out the bottom of the bottle was sludged up to the point nothing would run down into the drive. Took it off and cleaned it all out....problem solved (not for the drive though)

cleaning mine out now...switching to royal purple as always run that...seems to to me merc is pretty much crap if thats what it turns to....

My boat was a 2002, I cleaned it out for the first time in 2009. I'm positive the previous owner never cleaned it out either. I'd assume any oil that sat in a marine environment for 7 years isn't going to be much good.

Called John at The BravoShop got some NEO OIL he's selling and works great ! less wear and still looks new.

don't care on the # of years, oil not being run in something should not turn to this crap if it were worth a crap.... merc get dop $$ for this junk...wonder how many drives bought it from them running low and tank looking full ?? could clog real easy and you would never know....mine looked fine and clean...till I emptied it out...

If you changed it out at the intervals that you are supposed to, you wouldn't have a sludge problem. You going to run your car oil for 5 years and expect it to look clean too?

well considering whats in the reservoir has never seen the drive would not consider the oil there used...so still think it should not break down to sludge from sitting in a container...I don't run their crap and was just bring to attention a possible problem...which there seems to be...

At least on my drive, the level in the bottle goes up around 3/4 inch when on long high speed runs. So, there is some interchange of the fluid with the drive. When I bought mine, the sludge was 1/2 inch deep. Cleaned it out, refilled with Merc HP lube and am now on my second season with no sludge.