Black O/D oil

[MotorheadTed]

Drained the oil from my DP-C drive so I could remove top gear box. (see other thread)
This boat (1992 Sportcraft 232, VP 430A, duoprop) is new to me, have not even run it, going directly to "Restore/Repair mode. The boat was freshwater (great lakes) one owner boat until 2008, then brought here to florida, used a few times , then sat from 2010 till now.
The oil came out BLACK, I mean COAL black ! some spilled on the floor and you could see what looked like black power falling out of suspension and separating from the oil, which was light brown in color.
Anyone seen this before and might know where the black whatever might have come from?

 

[Bondo]

Re: Black O/D oil

Ayuh,.... I'd think it's just dirty oil...

 

[billbayliner]

Re: Black O/D oil

The dark gear oil does not sound good. I would pull the prop shaft bearing carrier and take a look inside of the lower unit.
Here is a link to a thread that will show you a puller that works and that can be made easily.

http://forums.iboats.com/showthread.php?t=376848&p=2523476#post2523476

All you'll need is two new O-rings and there is no change to any shimming if just pulling the carrier out.
Be very careful with the seals when removing. Wrap a thin layer of tape over the splines to protect the seals.

I'd also pull the transmission down and look inside that, especially the main drive gear bearings.
The transmission will require any O-rings or top cover gasket to be replaced.
Remember that the DP requires GL5 gear oil... not motor oil.

 

[erie_guy]

Re: Black O/D oil

MotorHead Ted,

Definitely drain, do a pressure test, and install fresh gear oil. I had a similar problem two years ago, and felt the black-dark oil was caused by a failed raw water pump that caused the engine to overheat several times. The other drive (twins) on the boat had clean and clear oil with no discoloration. Check your cooling system to make sure the engine and exhaust are not running hot.

erie_guy
Port Clinton, OH

 

[Don S]

Re: Black O/D oil

Since it's shiny black, it doesn't have water in it, so not sure what good a pressure check would be. My guess is the previous owner just never changed it. At least change the gear lube and run it and see what it does before you take the drive all apart.

 

[billbayliner]

Re: Black O/D oil

What if the oil had turned dark due to water contamination and or carbon steel oxidation?
If he pulls the carrier out, he can take a look at all three gears and get a pretty good look at several bearings.
He can also remove the shift mechanism and peek inside the upper unit.
Cost to do this is making the puller tool and three Orings.