Help: Leaking Driveshaft?

[Ourokaven]

Howdy, People! Can anyone tell me how this is leaking and what I need to replace? This is my ‘99 ST1100. There’s a very minor buildup of a thick black liquid that leaks from this area. This is the rear wheel, left side. Driveshaft. I think it’s Gear oil, because it’s coming from the location where you put in the gear oil, but it doesn’t smell like that pungent rot that gear oil tends to be. Also, it’s black. Is it potentially wheel bearing grease? This is concerning me and I’d love to know what I’m dealing with.

 

[Sunday Rider]

Welcome!
Have you owned the bike for long? Has the final drive fluid just been replaced and perhaps overfilled? Also after a high speed run on a very hot day, I had that happen. Only once though and I had just changed the fluid.

 

[FastST]

Replace the oil and torque the bottom nut firm enough. Upper one not too strong or you'll break it. After a ride check again.

 

[SMSW]

Replace the oil and torque the bottom nut firm enough. Upper one not too strong or you'll break it. After a ride check again.

I believe there is an o ring on the upper bolt. It's metric and you can probably find it at a good hardware store - or maybe even Hopot or Lowes.

 

[Ourokaven]

Replace the oil and torque the bottom nut firm enough. Upper one not too strong or you'll break it. After a ride check again.

This is exactly what I did, and I’m still getting that small amount of seepage. I can’t tell if it’s gear oil or something from the wheel bearing

Welcome!
Have you owned the bike for long? Has the final drive fluid just been replaced and perhaps overfilled? Also after a high speed run on a very hot day, I had that happen. Only once though and I had just changed the fluid.

Howdy! Thanks for the welcome. Yes I just replaced it. Gear oil smells putrid, I’ll never forget it lol. When I wipe my finger on it and smell, it doesn’t *smell* like that same putrid gear oil, which makes me worry that it’s something else. But if not the final drive oil, then what? Wheel bearing grease?

 

[Uncle Phil]

Could something been applied to the splines that wasn't the speced moly?

 

[Sunday Rider]

Howdy! Thanks for the welcome. Yes I just replaced it. Gear oil smells putrid, I’ll never forget it lol. When I wipe my finger on it and smell, it doesn’t *smell* like that same putrid gear oil, which makes me worry that it’s something else. But if not the final drive oil, then what? Wheel bearing grease?

I know what you mean about that smell of gear oil. But the fact you just replaced it raises a flag. Did you do anything else to the splines as Uncle Phil suggests?

The pic you took is of the right side of the bike. Right and left is determined as you are sitting in the seat.

 

[Ourokaven]

I know what you mean about that smell of gear oil. But the fact you just replaced it raises a flag. Did you do anything else to the splines as Uncle Phil suggests?

The pic you took is of the right side of the bike. Right and left is determined as you are sitting in the seat.

For as long as I owned it, which is since March, I haven’t messed with the that region at all other than changing the gear oil.

Howdy, People! Can anyone tell me how this is leaking and what I need to replace? This is my ‘99 ST1100. There’s a very minor buildup of a thick black liquid that leaks from this area. This is the rear wheel, left side. Driveshaft. I think it’s Gear oil, because it’s coming from the location where you put in the gear oil, but it doesn’t smell like that pungent rot that gear oil tends to be. Also, it’s black. Is it potentially wheel bearing grease? This is concerning me and I’d love to know what I’m dealing with.

Note: I’m aware that this pic is actually on the right side. I knew right, but somehow-.. *said* left. This is the right side of the bike on the final drive. Apologies.

 

[ST1100Y]

Could something been applied to the splines that wasn't the speced moly?

Was also my first suspicion...
But it could as well be the seal on the ring-gear, or the one on the forward/prop-shaft adapter...
One needs to remove the wheel and locate the root-cause...

GF's NT700VA had a slightly leaking f/drive seal; no biggie, was able to pull it from the outside (punch a hole in the metal part and "install" a sheet-metal screw to grapple it), clean all, inspect sealing surfaces, insert new seal...
Didn't even spill any f/drive oil during the process...



fully dry ever since...
Hint: the P/N shown in the photo is for an NT700VA; an ST1100 requires P/N 91265-MY3-003 instead!

 

[Sunday Rider]

I am thinking if there is a leak from the spline area the residue would be on the left side of the wheel.
Did you check to see if there is sign of leakage at the breather tube on the top of the final drive?
Open up the filling bolt and see if any oil drains out. Have some rags ready just in case.