Gray matter in final drive

[Jim/Maine]

Just finished my 10K service. All went well but, in a addition to Moly 60 the spline, we drained the final drive unit and it was totally saturated opaque light to medium gray color. Gary at Street Cycles Maine has always been great and was once again. He thought it might be condensation which seemed a reasonable guess. I was wondering if anyone has seen this. I had done a rather "interesting" 8 foot drop off a dirt road and kept upright and had a hard run back up and continuing on a dirt trail. I remember the rear drive sounding odd and it was hot. I am going to run her for a few hundred miles and flush and refill again. Any thoughts?

 

[tdragger]

"Gray matter in final drive" sounds like my brain as I age.

First thought was that water got into the drive somehow. Possibly through the vent cap.

 

[Navigator]

"Gray matter in final drive" sounds like my brain as I age.

First thought was that water got into the drive somehow. Possibly through the vent cap.

No that's "gray matter in final stages"

 

[Paul Bryant]

Why do you say this IDK ? "if you drain it with the drain bolt then be very careful when replacing it"

 

[tdragger]

A couple of Captains have stripped out the threads as they are somewhat delicate. Use a torque wrench to set the proper twist and don't go any further!!

The Drain Plug should be tightened to 15 Nm (11 lb-ft).

The Fill Plug should be tightened to 60 Nm (44.25 lb-ft).

 

[Jim/Maine]

Interesting thought about it seeping from the spline. I also thought about the vent cap and tried to have a look at it in the maintenance manual but found no reference. I had thought about analyzing a sample but will wait to see if it continues to present itself. Will probably drain it in a week or so and will report my findings. I too will be changing it out more regularly in the future.

 

[Willtill]

I have seen grayish fluid in both my previous Honda VTX; and the second time that I changed the final drive oil in my Rocket.

 

[Willtill]

I use Mobil 1 synthetic 75w90 gear oil

I use the same.

 

[Jim/Maine]

I have seen grayish fluid in both my previous Honda VTX; and the second time that I changed the final drive oil in my Rocket.

This sounds like a more common issue. Question is: Is it ok for the gears?

 

[Willtill]

This sounds like a more common issue. Question is: Is it ok for the gears?

I'm sure it's fine. Any minute amounts of water in the final drive from condensation is going to be emulsified in the final drive fluid; and if you ride your Rocket enough; it's not going to have a chance to damage anything.

If you let your Rocket sit for a couple of years and rusty colored fluid drained out.... yea... that would be an issue. Never heard of that even happening though.