Milky Final Drive Fluid

[Steve Kolenda]

Putting my 2011 1200RT up for the season and have changed the final drive fluid only to find the fluid looking a bit milky. Not sure where the moisture could be coming from as there is no leakage of fluid anywhere. I have changed this fluid several times in the past and the fluid has not been milky. Any chance that moisture is entering through the vent? Any suggestions?

[lawnchairboy]

can't imagine why you would have changed this fluid several times already on a 2011, how many miles are ya' piling up?

[BrianM]

Driven in much rain lately? The newer FDs have a vent in them. It may be possible that water has leaked in.

[dirtrider]

Morning Steve

 

A few possibilities:

 

Have you used the exact same brand/ type/ color of gear oil at each final drive change? If you changed gear oil brand, or type, or color, sometimes you end up with a strange looking mixture at next change.

 

If it's not a gear oil mixing issue then it could be a moisture issue possibly entering through the vent or from the R/H seal. Has the bike ever been pressure washed or ridden through deep water? If a ridden-hot final drive enters or encounters cold water it can cool quickly therefore sucking in some moisture. (circumstances have to be just right for this to happen though)

 

Or possibly bearing grease bleeding into the main cavity from a crown bearing leaking grease.

 

If you still have some of that removed gear oil you might send a sample to Blackstone labs for analysis. If it is good-to-go you will have a better winter without worry. If there is/was a moisture problem you still have time to deal wit it before the final drive sits stationary all winter (if it had moisture in it I would bet you didn't get it ALL out with just a single gear oil change).

 

If you don't have any oil left to send out then personally I would spin the rear wheel a revolution or two every week or two over the winter just to keep the bearings from sitting still with the possibility of moisture between the balls/rollers & races. A little moisture in the gear oil doesn't hurt much if the thing is ridden regularly but is the kiss of death to the bearings if it sits for extended periods.

 

[Steve Kolenda]

lawnchairboy,

 

I change it every 6000 miles when I change the motor oil. Fairly inexpensive and easy to do.

[Steve Kolenda]

dirtrider,

 

Gear oil brand and type has not changed. No pressure washing or riding through deep water. I think I have a Blackstone container around somewhere. Will they be able to detect the moisture or presence of grease? If it is moisture will the oil that I've drained out eventually separate from the water? Greatly appreciate you taking the time to respond.

[dirtrider]

Afternoon Steve

 

You should probably call BlackStone for their opinion of what they can & can't tell you from an oil sample.

 

If only a little moisture in the gear oil I doubt it will separate into water & oil.

 

One thing you can try if you have any (new) gear oil left is to start with plain gear oil in a jar, then add a little water & shake the jar. Keep adding a little water & shaking to see if you can match the color of what you drained out. If you can get close to what you drained out that might tell you if you in fact had a moisture issue & maybe how much.

 

[Steve Kolenda]

dirtrider,

 

Unfortunately I just finished off a bottle and the newer oil that the dealer sold me has a Castrol label and I think it is green and not red. Although I have the oil from my previous change and I will try adding a drop or two at a time to see what it takes to match my current oil. I will also call Blackstone. Thanks again for your time.

[Norm 427]

Being a 2011 you've still got warranty on it, so maybe let a dealer look at it.

 

 

[Steve Kolenda]

Norm,

Thanks for taking the time to post. Bike is put up for the winter however I will be at the dealers in a couple of weeks and will discuss my findings with the service manager. I even have a sample to bring with me.

[racer7]

The rear diff gets pretty warm in normal use- maybe 130 or so depending on ambient temp and speed. And if you suddenly cool a hot diff with water it would certainly be possible for the resulting vacuum in the diff to pull in any water around a vent UNLESS the vent is one with a built in hydrophobic membrane like many industrail tank vents. Haven't looked at the vent part on a camhead so don't know the answer about a membrane- but one could be added if not there and you wish- sinple machine job.

 

If what you're seeing is white, its probably water. Gray fuzzy stuff is just normal wear suspended and grease would probably produce an intermediate brownish color.

 

Anybody ever seen water get in through the front of the FD after getting trapped in the shaft boot?? Is yours tight and water free??

 

FWIW, I do FD lube changes when I do a rear tire change- have to have the wheel off anyway....