After about a hour of running the drive oil reservoir empties out thru the vent on the reservoir cap into the bilge. I'm running XR's with Billet Marine top caps and showers. If I keep about a 2" of oil in the starboard reservoir it doesn't leak out, the port one empties. Using Merc High Per. synthetic drive oil.

Check the drive, you may have water in the oil from a bad seal or leaky top or front cap. I've seen this happen a lot when there is a leak.

If you're losing oil thru your resorvoir it is likely for one of two reasons:

#1. Like Panther said you may be leaking water into the drive, thus overpressuring the system
#2. And I just experienced this one, the pinion bearing came apart and the vertical shaft was rotating against the housing, not in the bearing, thus creating excessive heat buildup. This expanded the drive fluid and almost exploded the drive reservoir.

An easy check, if your boat is out of the water, is to drain a little drive fluid from ther suspect drive. If there is water, it will be the first out the drain. If you've got heat issues, the oil will have a pungent smell (Death oil). The magnet on the lower and upper oil drain plugs would also help to indicate if you have a drive failure in process.

You know saying that, just about every XR is a drive failure in process

SteveDavid,
could you expand on that second idea. Which pinion bearing are we talking about here? I have not seen that yet, would be nice to have the info..
Thanks
Dick

I remember this thread about the resevoir cap. BTW. I have switched my drive oil to Redline Heavy shockproof oil, seems like there is less variation in oil tank from cold to hot which must mean the drive oil is staying cooler than it was with the merc+ oil

Mark
http://www.offshoreonly.com/forums/s...ight=drive+oil

"must mean the drive oil is staying cooler than it was with the merc+ oil "...no it 'could' be...

you may have an internal mechanical issue...OR the original drive oil level was set too low....resulting in too much air in the drive,,,,air expands more with less heat than oil....and 2 fold the low oil level will also give you inadequate lubrication thus expanding that air even quicker....O, if this happened, you may have caused internal damage??? take the top and rear cap off REGUARDLESS of what you find outside the drive.

but hey. whata i know

[QUOTE=audacity]"must mean the drive oil is staying cooler than it was with the merc+ oil "...no it 'could' be...

I know it wasn't a very scientific test. but thru 5 changes with merc oil, 33 mile run oil started at low mark on bottle and ended run at high mark. Made this same run 3 times with the redline starts at low mark and is 1/4" short of high mark. Better lube should mean less friction?

Mark

Boat's coming out tonight, pull drive apart and check it out.
Is Merc drive oil really that good? What's everyone using?
Jamie

that level in that bottle could have more to do with cst numbers than anything else...

if ya want to talk tmps? then removed the oil level variable (it must be controlled) install a TC and remove other variables and run set parameters...

other than that you can NOT correlate 'friction' with oil level(s).

Joe,
TC= thermo couple? cst=?

As i said, not scientific, just observation.
Also noticed magnet was clean at first redline oil change. Based on that and the way that the redline sticks to the side of the bottle, I am happy with the switch despite twice the cost.

My thinking was more friction=more heat=bigger oil level change. But this would be far from the first time that I was wrong.

Mark