Gear oil leak

[sbc385]

Hello,

I have a 2006 Qianjiang 50QT-2. It recently started to leak gear oil out of a hole on the bottom of the gear case. I removed the cvt cover and the gear case and from what I can see, oil is leaking past the axle seal and out this hole. I think this hole is supposed to be there so gear oil doesn't leak onto the brake shoes-maybe I'm wrong. I replaced the axle seal with the same one that was in there (I got the numbers off the old seal) and replaced the bearing with no luck. Its still leaking-bad. All 100ml of oil leaked out on a 20-30 minute ride. Disassembled again, I noticed that the seal moves back and forth between case and bearing, is It possible there is a washer/spacer  missing to take up some of the slack? I didn't see one the first time I disassembled it. I don't see how this seal is supposed to do its job with that much play between bearing and case. I've been trying to find a parts break down, or pictures, or even a video of the same model I have but I'm not having any luck.  The number stamped on the rear of cvt is QJ1E40QMB  63044852. 
Any help would be greatly appreciated.

Thanks

[90GTVert]

Usually the small hole on the bottom of the case is just an overflow/overfill hole. Known to weep some fluid during and after rides, especially if the level is too high, but generally just drops... not losing all of the oil.

There's a passageway that allows fluid to go in there. Maybe see if something is causing that not to be sealed so fluid at standard levels could leak.

If the axle seal is moving, that's a problem. Once driven in, it should stay put till driven out. Wrong seal or worn cases maybe. Bearing and seal info for Minarelli clones is here, with pics of it all :
49ccscoot.proboards.com/thread/6145/minarelli-clone-bearings-seals-torque

Video of a gearbox assembly here. Focused on gears, but maybe you can see something useful :
youtu.be/UXc93_RUTJ0

If it's leaking past the axle seal, maybe that's really the culprit? If the axle is worn, rough or damaged then it could leak even with a good new seal and damage the seal to make it worse.

[sbc385]

Thanks for the link on the Minarelli clone! Mine looks very similar to the short case. And excellent YouTube video!

I was hoping for a pic of the axle seal between the bearings. The outside diameter of my seal does not fit snug in the case. If it did, it would cover up the over fill hole in the bottom of the case. The inside diameter of the seal does fit snug on the axle shaft, but there seems to be an excessive amount of play between seal and bearing.
I've replaced the seal twice, and the bearing once. The first seal I replaced was the same seal that was in there numbers matching. After a short ride, all the gear oil leaked out. I replaced the seal again, this time with a slightly wider seal in hopes of taking up some of the excess gap between bearings. Again, no luck. All the oil leaked out. I will post some pics as soon as I figure out how to do it.

[oldgeek]

The seal should not contact the bearing. It should fit tight in the housing and snugly on the shaft. If it is loose in the housing possibly some RTV or other sealant may help retain it in the housing.

[sbc385]

Aug 7, 2023 20:41:41 GMT -5 oldgeek said:

The seal should not contact the bearing. It should fit tight in the housing and snugly on the shaft. If it is loose in the housing possibly some RTV or other sealant may help retain it in the housing.

I agree with you. I think it should fit snug in the housing. Im hoping to get back out there this weekend and do some more investigating.