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Discussion Starter · #1 ·
Hi All,

Looks like I've developed a small oil leak on the drive-shaft "breather cap".

How difficult is this to fix? DIY? Or should I find a mechanic? Any parts I need to get?

Found 3 drips on garage floor about the size of a quarter (each).

thanks in advance,
~Lou
 

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You sure it is the breather? Usually it is the drain plug or the bearing seal, you need to remove the wheel and check the seal. Oil is not at the breather unless the bike is on it's side.
 
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Discussion Starter · #4 ·
You sure it is the breather? Usually it is the drain plug or the bearing seal, you need to remove the wheel and check the seal. Oil is not at the breather unless the bike is on it's side.

Hey Brother,

yes - definitely the breather cap.
You sure it is the breather? Usually it is the drain plug or the bearing seal, you need to remove the wheel and check the seal. Oil is not at the breather unless the bike is on it's side.
Hey Brother.... yeah, def the breather. I cleaned that whole area last night. This was after coming home for lunch. You can see the drip trail.

What causes these to leak if they're press-fit?
Tire Wheel Automotive tire Light Motor vehicle
 

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Ok, Did you fill the differential off the bike? You refill on the bike and you only fill to the bottom of the fill hole. Do you see how high above the fill hole the breather is? The level of the oil should only be to the fill hole , that is why I said it won't leak unless on it's side.
 

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Discussion Starter · #6 ·
Ok, Did you fill the differential off the bike? You refill on the bike and you only fill to the bottom of the fill hole. Do you see how high above the fill hole the breather is? The level of the oil should only be to the fill hole , that is why I said it won't leak unless on it's side.
Ok, Did you fill the differential off the bike? You refill on the bike and you only fill to the bottom of the fill hole. Do you see how high above the fill hole the breather is? The level of the oil should only be to the fill hole , that is why I said it won't leak unless on it's side.
I have not filled or refilled the rear diff. I'm at work now. I just came back from outside and with a fellow biker employee, we tapped on the cap with a rubber mallet VERY gently. Looked like it was slightly cocked so I gave it a few taps. Will check for drips again when I get home.

The only work I had done recently was valves replaced. The certified Yamaha mechanic did have to remove the rear wheel and take engine off frame. The ONLY thing I can thing of is perhaps when he laid the rear wheel down, something or somehow the breather cap got bumped...probably without him even knowing it. When I get home, I'm going to check the level of the diff.

You're spot on: everything I've read says to fill rear diff with approx. 200ml of 80W90 gear oil, or.... up to the bottom of the threads of the fill hole.

I'll be checking level when I get home. My mechanic says he didn't mess with any of that when he did the valves....

More to come - I'll update this thread after I get home and do those checks. Let's hope giving it a few taps has helped it seat more properly.

thanks brother....
V/R,
ICCS(SS)
 

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clymers says to check the level with the bike upright, to the bottom of the threads. if they filled it upright rather than on the kickstand i'm guessing there would be more than on its side.possibly overfilled. i don't know now which is right.
 

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Discussion Starter · #9 ·
clymers says to check the level with the bike upright, to the bottom of the threads. if they filled it upright rather than on the kickstand i'm guessing there would be more than on its side.possibly overfilled. i don't know now which is right.
Thx Nick. Well, I just got home from work and the entire diff exterior is oil free. 馃槈

Below pic is after I just got home. Looks exactly the way it did after a few gentle taps with rubber mallet at work a couple hours ago.

Tire Wheel Automotive tire Motor vehicle Tread

I've got it propped upright now....Will check the level in the morning.

Stay tuned....:)
 

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Discussion Starter · #11 ·
UPDATE Saturday 11.19.22*

Well, it sat all nite and no drips. I checked level with the bike upright and it was just to the top of the fill hole threads.

My mech didn't change or refill the diff when he had the bike but, he said sometimes those "breathers" can become stuck. He believes tapping it with rubber mallet (yesterday) probably freed it up so it's doing its job again.

Alls well with the world once again. 馃憤

Thx to those who chimed in.

Ride Safely...
~Lou
 

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Discussion Starter · #14 ·
Rear Diff has not be changed in 3 years I've owned the bike.
Thanks. As mentioned above, the rear diff has not been changed or topped off in the 3 years I've owned the bike.

I'm gonna chaulk this issue up to the idea the breather has just become stuck somehow.

I've ordered an OEM replacement breather and will change it AND the gear oil (80W90) next week when it arrives.

Thanks,
~Lou
 
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