Final drive gear oil change, did I wait too long?

[KrisZ]

Decided to replace the final drive gear oil on my Honda Valkyrie. The bike has almost 25k miles and apparently the final drive was serviced just before I bought it at 9k miles.
This is my first drive shaft bike so I don’t know if this looks normal or not. Honda calls for 24k mile change interval, but I’m not sure about that.

But aside from the color, the drain plug magnet had very little deposits on it and the oil didn’t have sparkles in it under direct light.

 

[Merek]

It looks fine and just like what used gear oil looks like. The shaft drive typically on motorcycles don't really hold that much oil so if anything you can try changing it out a bit more often.

 

[Merek]

The Honda's are practically bulletproof, how many miles are you running for oil changes? I'd probably change the final drive every 3-4 changes.... maybe 12-15k miles. This is BITOG afterall so what is the oil that you're using?

 

[KrisZ]

I’m running 3-5k OCIs on this bike with Mobil Super 15w40. 10k for final drive is probably a good nominee to remember and it only holds 150ml of gear oil, so not much at all.

 

[Ride_Red]

I use Mobil1 synthetic 75-90 gear oil in the final drive of my Honda ST1300. The manual says 20K mile change interval. I usually change it every other oil change, since I have the pan and tools already out.

 

[Overfill]

Pics of the Valkyrie? I love those bikes

I would base it first on what is shown on the magnet.
Then, how dark it is on a sample (finger/glove/paper towel/ect.)
Your report and images would have me satisfied.
Being Hypoid, it deserves GL-5 level of protection.
You could probably go a much longer interval on a boutique like Shockproof, but I don't figure many people would value that

 

[KrisZ]

It got the GL5 hypoid 80w90 oil from Amazon, Quicksilver is the brand, never heard of it, but should do just fine.

Here it is in all its glory

 

[barryh]

Being Hypoid, it deserves GL-5 level of protection.

Is it really hypoid as in the pinion offset from the crown wheel. I thought most shaft drive motorcycles would have gone for a simpler spiral bevel with the pinion in line with the crown wheel axis like my BMW. It's more efficient too. BMW still calls for GL5 though.

 

[Overfill]

Is it really hypoid as in the pinion offset from the crown wheel. I thought most shaft drive motorcycles would have gone for a simpler spiral bevel with the pinion in line with the crown wheel axis like my BMW. It's more efficient too. BMW still calls for GL5 though.

That's an interesting point, for sure. If anyone can say, it might open GL-4 options up. But, without knowing, I'm more tentative given that they ask for GL-5. I'm not sure what advantages those GL-4 options would provide in this service.

 

[barryh]

That's an interesting point, for sure. If anyone can say, it might open GL-4 options up. But, without knowing, I'm more tentative given that they ask for GL-5. I'm not sure what advantages those GL-4 options would provide in this service.

Doesn't GL5 just contain double the same anti wear additives that are in GL4. As you say I don't know what practical advantage using GL4 would bring over GL5 even if it was permissible.

The only thing I wonder about and this is just speculation on my part, is that anti wear additives are about protecting wear at the gear tooth high pressure contact points. What would be the preference between the two for lubrication of the bearings. My BMW also specifies GL5 for the gearbox with very frequent change intervals but even then it's not especially durable with bearings failing relatively early compared to a car manual transmission that will do very high miles on the original factory fill of what by comparison is very thin MT oil.

 

[BigCahuna]

Years back, there was discussion about the difference between the gl-4 and gl-5 oils. it was said that Gl-5 is for transmissions or rear ends, that do not contain brass parts in them, like syncros. And that Gl-4 doesn't have the same corrosive chemical that causes the corrosion, and turns brass parts black. And could cause premature failure. If the rear end of your bike doesn't contain any brass parts in it, you could probably use either oil and be just fine. I would check a service manual to see what type the maker recommends.,,