Here's another twist , mine was foaming and filling up ,do to a drive overheating. The oil was expanding threw the c.v. back into the bottle. Merc. high per. oil /w around ten hours on it. When I drained the drive,. the oil it was black with alot of brass looking particals .

Could it be getting hot?
Lower drives are new Imcos, and they feel pretty tight.
Just drained oil, looks new.

P.S. Thank you bcfountain, I didn't know about paste.
Might have to give it a try

Hey guys, could C V be bad ?

What's c v?

DMAX mentioned it,
I'm assuming its a little check valve in uppercase?
I think thats what that is?
In oil passage where upper joins to
drive shaft housing.
Someone enlighten me here?

That check valve cant get to the bottle. At least I dont see how it could. If heat is an issue, it shows up in several places. Are you running a shower? Do you see white on the sides of the upper? If you run it long enough, hot, the oil does turn black.
The lowers should start to loosen up after about 10hrs of running. Spin the props and see if they move freely? After about 20hrs they should spin without too much force.
Brass particles would indicate misadjusted shift linkage, holding the shift fork against the brass rings.. but your not seeing that.
If it isnt water, I would look at temps next. A tight drive would cause excess heat, for sure. One of the preloads on the tapered bearings could be too tight?. Keep with the info.. we'll figure this out..

Dick

Im assuming preload is correct,
Lowers are new from Imco. They both feel exactly the same, but are fairly tight,(I'm also comparing them to my old Bravo's that had some time on them)
Yes, I'm running drive shower, and no other signs of heat or brass particles.
Also I didn't run them very long.

Approximately how many hours?

H-O-T, had one do this and the guy puked the upper gears after 15 hours.Somone had put a newer style x gear set in a older upper and put the .060 series shims instead of the .050 series shims.A tooth broke,then it wiped out the race tower.Did you get the entire lower from Imco or did you get an empty lower w/ vertical and assemble it?

Had a couple on my old 32 Velocity that did a similiar deal. Brand new uppers, one lasted 2-3 hours and chit, when we pulled the back cap to take a look the Merc lube was like whipped cream, failure was heat related and took out the tower, gears, cone clutch, and the case. Replaced that one, back in the water and another hour or so the other one went, same deal with the lube and internals. Have never run the Merc lube in a drive since, I broke more drives after these, but never saw the whipped cream deal again, just the broken parts.