The Yamaha Road Star Warrior Forum

1) Remove the muffler
2) Remove rear head pipe assembly
3) Loosen the drain plug but do not remove
4) Put a piece of cardboard between the frame and the
transfer case underneath the drain plug to channel
the oil into the drain pan
5) Remove the drain plug and lean the motorcycle to the
right to fully drain the case
6) Reinstall and torque the drain plug
7) Remove the oil level check bolt and the oil fill plug
With the motorcycle in the level position, fill the transfer
case with SAE 80 API "GL-4" Hypoid Gear Oil
until it just starts to pour out of the level check hole
9) Reinstall and torque the level check bolt and the filler bolt
10) Reinstall the rear head pipe and muffler

Drain
Fill Hole

Hey Carknee, great instructions and pics. Beats the heck out of the manuals suggestion to bring to the dealer. [8D]
I thought I would add, for any newbies, that it only takes .42 quarts, so don't expect much lube.
Also, as an alternative, when filling through the fill hole with the bike level, using a flashlight you can easily see when the lube level reaches the center of the level check hole without removing the bolt. No biggie, just saves trying to plug the hole before any lube escapes, maybe a little less wipe up.

Good job, CarKnee, as usual.
So what you think about using synthetic in this application? Red Line has a GL-4 70W80 lubricant called "MTL." Amsoil has a GL-4 80W90. What we think?

folks, you dont have to remove the muffler for transfer case service. i made a tool from a piece of plastic that resembles a cut down butter knife. the hardest thing was starting the threads on the filler plug because of the strange angle & limited space, but it is easier than removeing the exhaust. hope this helps

Great instructions nice pics too

Great job, Carknee. I'll be changing mine tomorrow, as usual your directions were right on time!

Best instructions I've seen. Much better than the Yamaha service manual...

I can't find any straight 80 weight oil even on the yamaha website all I see is 80W90. Will the 80W90 work? I would much rather use what the manual calls for. Got any suggestions on were I might find a straight 80 weight. Already tried all the parts stores in my area. Tried the amsoil and valvoline web sites too and no luck.

Redline makes a 75W80W GL-4 oil that is commonly used in T-5 Mustang manual transmissions. Another option is a fluid that meets John Deeres J20 specifications or Ford MC 134 Tractor Hydraulic Fluid specs. Chevron calls these THF 1000. Other majors have their own names for these driveline oils. When I worked with Amoco, we had these fluids running in bothe Nascar and Busch cars with literally NO WEAR anywhere in the driveline. Best part of these is the fact that they don't have the super high sulfur phosphorous content of the GL-5 lubricants, which can cause seal and metal corrosion at high temperatures. Also, the 75/90 or 80/90 are too high in viscosity. Yamaha recommends a 80W GL4 which is more like a SAE 20 motor oil in viscosity. Plus the GL4 does not have the extensive additive treat rate so it won't eat up the soft components. If you need more detail, email me at SDVA@Chevrontexaco.com I'm a lube engineer with almost 30 years experience in product formulation and will be glad to help you with your concerns.

Sam Vallas
Lubrication Specialist, CLS
Orange City, Florida
386-775-9309
sdva@chevrontexaco.com

Thanks Carknee for the instructions. Just finished this job, and thought I would add a couple of notes. First, I tried to do this maneuver without removing the muffler and header, and it was a pain in the butt. I managed to completely munge the oil filler plug with various utensils and ended up ordering a new one ($11.50 from Yamahahahaha). Removing the muffler and header may seem like a bigger pain, but after doing the job this way it was worth it. Second, the rear header is easier to get back on if you loosen the front header nuts just a tad. This gives you a little "wiggle room" to make sure everything mates back together without undue force. Further (FYI), I did this without a bike jack, and it worked just fine.

Thanks again!

-M

Should the transfer case oil be red like a auto trans fluid?
Looks thicker than trans fluid.
What do you guys think?

As I recall, I used Mobil one synthetic gear oil.

Thanks for the instructions CarKnee, they worked perfectly even with the chrome cover installed instead of the stock one.

This is great! I have to do this in couple of months. Great job CarKnee!! I'm a fan of your howto threads!!! []

how much gear oil is needed?