15 M8000 Chain Case Leak

[bowhunter11199]

About a week ago I bought a 15 M8000 with 1600 miles. Today during a ride I noticed the chain case was leaking oil. The previous owner said they replaced the chain case fluid by sucking out the old oil and then putting in a new bottle. Did they didn’t crack the case. As far as I could tell, it doesn’t leak when the sled is not being used


It looks to be leaking from the filler cap(first picture) but I’m not sure that’s the only spot (second pic is below the fill plug where it looks to have a small crack but it could be just how the part was cast when new). I’ve put about 60-70 miles on the sled in two trips since I’ve owned it. The chain case oil level is 3/4-7/8 full on the sight glass.

Is it common for just the full plug to leak? Should I break the case apart?

 

[summ8rmk]

Fill plug leaking is expected. Pull it out and look at it, u will see why.
The case has a rubber gasket, I doubt it's leaking. But it could....

Sent from my SM-G998U using Tapatalk

 

[bowhunter11199]

I used to ride an M series and I went down the mod route. I later upgraded to an XM (14 and then 16) and it was a night and day difference.

Get the new sled.

Fill plug leaking is expected. Pull it out and look at it, u will see why.
The case has a rubber gasket, I doubt it's leaking. But it could....

Sent from my SM-G998U using Tapatalk

Thanks for the info. I found a post about someone using g a 1” boat drain plug. Think I’m gonna fill the chain case back up and try the not plug and see if it still leaks

 

[summ8rmk]

Thanks for the info. I found a post about someone using g a 1” boat drain plug. Think I’m gonna fill the chain case back up and try the not plug and see if it still leaks

Make sure there's a vent on the back of that case up by the jackshaft, if not that filler plug may also be the vent

Sent from my SM-G998U using Tapatalk

 

[bowhunter11199]

There is a small aluminum 90 degree angle vent at the top font of the chain case. I could also just try some grease on the original plug and see if that works?

Make sure there's a vent on the back of that case up by the jackshaft, if not that filler plug may also be the vent

Sent from my SM-G998U using Tapatalk

 

[bowhunter11199]

Update, after the sled has set for two days, the oil level is up to within 1/32” of the top of the sight glass. So I haven’t lost much oil. I cleaned the case off to see if it continued to leak and it hasn’t. I’m thinking it was leaking out of the plug and running down the case. Considering putting a little bit of grease on the plug and reinstalling to see if that keeps the chain case fluid from getting past the full plug and leaking

 

[sno*jet]

I think you're overfilling it. 1/2 to 2/3 up the sight glass is full on my model. The seeping plug is annoying but not bad at 1/2.

 

[Old & slow]

The plug was updated in 2021,
3602-305 plug
0830-185 o-ring x2
Under 10 bucks and doesn't leak

 

[Joe.G]

Put a little grease on the Plug, That should stop it. I run mine about a 1/16th from the top.