Oil Leak from the Final Drive.

[10éréRider]

I went out to the bike to take it for a ride and discovered a puddle of oil under the pumpkin. See photo for where the leak is coming from.

What am I in for? Just a gasket or seal, or is there something more sinister lurking inside there? Anyone with some experience on this have any advice?

10éréRider

 

[steve68steve]

BT, DT.

There's a seal on the wheel side of the drive unit which is a common culprit. I had one fail. After a few weeks of sticky crud on the drive side of my back wheel, I still didn't figure it out. It took trailering the bike and finding a puddle of oil under the pumpkin to realize it. I had the same wet spot right on the bottom of the pumpkin.

I obviously can't guarantee that's what your problem is, but it's a strong possibility. If that's what it is, the seal is cheap and relatively easy to replace DIY with a few tricks.

 

[Karl]

I just disassembled that seal and cleaned it and have had no leak since. Don't worry, your final drive is fine, even with a huge amount of oil in the drive and the wheel, the oil level only drops a fraction. In saying that, it is easy to check the level is OK until you get it fixed.

K

 

[Cycledude]

So far the leak looks VERY small.
Did you maybe happen to overfill the final drive ?
When you fill the final drive do NOT spin the wheel during the filling process because the oil that sticks to the gear will cause it to be overfilled. That’s a little lesson I learned many years ago with a Honda motorcycle, thought I was doing a good thing getting that extra oil in there, when we got out to Montana where there was no speed limit we ran all the way across Montana at over 100 mph , at one gas stop the final drive was leaking so we stopped at a car wash to wash it off then drained the old oil and refilled it without overfilling it and it never leaked again.

 

[10éréRider]

So far the leak looks VERY small.
Did you maybe happen to overfill the final drive ?
When you fill the final drive do NOT spin the wheel during the filling process because the oil that sticks to the gear will cause it to be overfilled. That’s a little lesson I learned many years ago with a Honda motorcycle, thought I was doing a good thing getting that extra oil in there, when we got out to Montana where there was no speed limit we ran all the way across Montana at over 100 mph , at one gas stop the final drive was leaking so we stopped at a car wash to wash it off then drained the old oil and refilled it without overfilling it and it never leaked again.

I haven't added oil for a while as it's not at a service interval. I did about 700km last weekend and no sign of a leak. I did about 50 on Saturday and when I went out today I noticed the leak. I went for a short ride today but because I was unsure how much leaked out perhaps while riding, I topped it up till it ran out the filler hole. I didn't take very much at all so I think it just started leaking.

Any special tools required to replace the seal? I've had the rear wheel off a number of times so is it just the bolts on the back side that need to be removed?

10éréRider

 

[jrusell]

There are 2 ways to replace the seal.
1- self tapping screw into the existing seal and then pull it out. Lube new seal and push into place.
2- remove cover on pumpkin, replace seal and o-ring, reinstall cover.

Personally I would just use the screw method. Here are 2 links to the different methods.
https://thetenerist.wordpress.com/2014/09/28/yamaha-st12-inner-shaft-seal-replacement/

Scroll down to post #38252 for pics and instructions.
https://advrider.com/f/threads/the-yamaha-super-tenere-xt1200z-big-thread.545850/page-1913

I would try a seal saver before I replaced the seal. Could just be a bit of grit/dirt that can be easily removed with seal saver.

 

[LostDonkey]

I recently replaced my seal. Here's a tip or seating the new one. Take a lead pencil (I 'borrowed' one from my daughter's school bag) and using a blade, trim one end so that it fits within the gap (against the seal) and square it so that there is no pointed or rounded end to it. Then use a rubber or wooden mallet to tap the seal home. You'll know it seated when you tap it and it gives a 'solid feel' feedback. The pencil wood is soft so there is little chance of damaging or marking the seal if you hit it too hard.

 

[10éréRider]

Update to my seal leak. Since a replacement seal was backordered and probably 2 weeks out, I decided to give cleaning a try. I didn't have a Seal Mate and it was a lot to ship a tiny piece of plastic,No one had one in stock that I could find. I tried something I saw in the reviews of the Seal Mate. One guy mentioned using a feeler gauge which I had. I put a gentle curve in it so the edging would stay tight to the inner steel. It sounded gritty as I carefully slid it around and I cleaned it frequently. It eventually sounded nice and clean. After 4 days and a few hundred kilometers of riding,,,NO LEAKS!!!

I did order up a new seal so I will have it on hand if needed.

Curve on the feeler gauge using a AA battery. Also attached a picture of how I level my wheel to reinstall. Crude but easy to line things up.

Thanks for all the advice. Saved me some time and money.

10éréRider

 

[LostDonkey]

Thanks for the update. That was a great idea! (Wish I'd thought of that before replacing my seal.) Nice use of wedges too.

 

[Checkswrecks]

Glad it worked out.
While I do keep a couple of SealSavers around, most any piece of thin plastic cut from trash works for this and you won't risk cutting the seal or scratching the face.

 

[jrusell]

Old piece of film negative works great as a seal saver.
I am sure some of you have a few pieces in an album somewhere.

 

[Madhatter]

who uses film these days ?

 

[regder]

Thanks for all the advice. Saved me some time and money.

10éréRider

Good job on jimmy rigging something. Just in case you ever need one again, I think I bought my Sealmate from Royal Distributing.