The color of oil?

[willowstreetguzziguy]

Just changed my rear gear oil and transmission oil yesterday. I had the bike serviced 11,000 miles ago. All the fluids were changed, at least I thought. When draining the rear gear oil it was dark but the tranny oil was like new. So... two questions... 1.) Was the rear gear oil  dark because it gets a lot of wear in 11,000 mile, or maybe because it wasn't changed when I thought it was supposed to have been changed.?  2.) The transmission oil was like new after 11,000 miles because it doesn't get much wear?   

[fotoguzzi]

The rear drive has molly added so it looks black.

[John A]

Dow Corning Gear guard  M gear oil additive is the real stuff. 1 liter will last you thru a couple bikes if you put 100K miles on them. don't want to start an oil thread so look it up yourself :Beating_A_Dead_Hors e_by_liviu

[BRIO]

Dow Corning Gear guard  M gear oil additive is the real stuff. 1 liter will last you thru a couple bikes if you put 100K miles on them. don't want to start an oil thread so look it up yourself :Beating_A_Dead_Hors e_by_liviu

The Carc manual states that both gearbox and final drive oil should be changed every 10.000km or 12 months which sounds ridiculous. I can't figure out why any final drive oil should be changed so often in non racing applications.

[Triple Jim]

I can't figure out why any final drive oil should be changed so often in non racing applications.

I can't either, but I can think of a reason why a manufacturer would say you should.

[Ncdan]

How often do you change the rear end lubes  in your cars and trucks in a hundred thousand miles? That's right 0. Myself, years ago I got tired of draining out perfectly clean clear and no burnt smell, rear end and trans lubes and stopped the madness. I've put 50+ thousand miles on bikes with no changes and no issues. It's fine if other folks feel better when they change like the factory recommends but I'm past that.
No arguments, just my point of view:)

[willowstreetguzziguy]

BTW, when I changed it, I put Spectro SAE 85 W 90 Hyploid Gear Oil GL-5 in both the Transmission and Final Drive.

[Mike Tashjian]

Rear drive is ring and pinion which is different than most transmissions. Both the transmission and rear drive oil will become contaminated at some point whether you can see it or not. Regular maintenance is cheap insurance for the long haul. I want my days on the bike to be as trouble free as possible.   Mike 

[SmithSwede]

My two cents, after 50,000 miles on my V7. 

The transmission oil always comes out looking brand new.

The final drive oil always comes out looking beat up.    Black and gnarly is the best.   At its worst, it's  puke green due to gross water contamination.

I think I've fixed the issues with the rubber boot on swing arm causing non-trivial water contamination at final drive.   

Anyway, these are small volumes of oil.   This oil is vented directly to the atmosphere (not to a bellows or air cleaner box).  So even if you don't have gross leakage of water into these systems, you are still picking up some amount of ambient humidity, condensation, dust, road grime, spider legs and other crap.

I'd change it regularly.  Cheap insurance.     

[Muzz]

I think the Baby B holds 170ml in the rear. 20mls of moly and something like 80/140 in the rear. If you use full synthetic in the rear you evidently don't need moly, however, I still use dino after some reported leaks using synthetic.