Gen2 weeping from top of differential

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TheFleshRocket

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My '14 has about 9K miles on it, bought new in '15. I did the 600-mile differential fluid change with the right Yamaha fluid. I followed whatever procedure was posted on starvmax.com at the time. I've periodically noticed a slight weep from the top of the differential, apparently coming from the fill hole. I haven't taken the cap off to see what's up. Did I just overfill it? Should I just suck a little out? I still have the rest of the differential fluid, so I could do another change, too.

I found this thread: I say huh? (Diff oil change)

It lists this as the procedure. Is it still accurate?

So after a few changes there is definitely a preferred method to changing the diff oil. Keep in mind that this is GEN2 only. GEN1 has a different method (outlined below the GEN2 method) The problem is that if you just put oil in until it starts seeping out the hole, your pumpkin will spew sauce after a hard ride...

GEN2:
---------------------------
01. Pull the breather cover, fill plug, and drain plug (in that order)
02. Drain the oil.
03. Spin the tire.
04. Let it sit for a while.
05. Spin the tire again.
06. Let it sit for a while again.
07. Put the drain plug back in.
08. Pull the weep plug.
09. Pour a little oil in.
10. Spin the tire.
11. Check the weep hole.
12. Repeat the steps 09 through 11 until the oil barely starts down the threads in the weep hole.
13. Put the weep plug, fill plug, and breather cover on.
---------------------------

The slower you go with steps 09 through 11 the less likely you will spew oil out the breather on a hard ride.
 

ShawnD

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My '14 has about 9K miles on it, bought new in '15. I did the 600-mile differential fluid change with the right Yamaha fluid. I followed whatever procedure was posted on starvmax.com at the time. I've periodically noticed a slight weep from the top of the differential, apparently coming from the fill hole. I haven't taken the cap off to see what's up. Did I just overfill it? Should I just suck a little out? I still have the rest of the differential fluid, so I could do another change, too.

I found this thread: I say huh? (Diff oil change)

It lists this as the procedure. Is it still accurate?
No need to 'suck a little out'...just remove the 6mm bolt that sits at about the 3:00 position, with the bike upright & any excess will flow out.
 

TheFleshRocket

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No need to 'suck a little out'...just remove the 6mm bolt that sits at about the 3:00 position, with the bike upright & any excess will flow out.
Will do.

Thinking back, I bet I did the differential fluid change with the bike on a stand.. which would have kept it properly centered upright, but which would have also made it tilted forward slightly, so I probably overfilled it.
 

ShawnD

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You could get someone to open the bleed screw while you straddled the bike.
 

2017VMax

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I went through the same exact issue on my 17 when I 1rst bought it. I had mine on double jack stands. I actually found oil on rear tire. I'm not sure what I'd do differently but I also followed the procedure to a T.
 

ShawnD

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Seems logical that if it's weeping oil it's overfilled...maybe lean the bike slightly & let more run out. I've not experienced it on mine. Is it something that happens only with high speed runs?
 

2017VMax

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Happened to me on a 3 hour tour from PA to NJ. I was getting it in... Vroom... Vroom... Used to take that ride alot to visit family. Next time I will measure exactly what comes out and put that back in.
 

02GF74

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First photo shows rear axle comprising axle casing, differential, two half shafts and what appears to be swivel joints.

Below is a photo of a differential.

Confusion arises ad they both have a crown wheel driven by a pinion. A differential has clever shit inside that allow the two half shafts to turn at different speeds.

Screenshot_20210702-205016.jpg
 

02GF74

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Apologies, FRONT axle as the bits on the end swivel to for steering. (unless it is from 4WD 4WS vehicle which is less likely)
 
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