Pumpkin Leak

[RossKean]

I did a search and not much recent and nothing that matches exactly what I have found...
Anyway, I was removing the rear wheel to do a tire change and when the wheel slipped off the pumpkin, about 5 mL or so of black gear oil drained onto the floor. I wiped off everything with paper towels and there has been no obvious leaking since (about an hour ago). There was NO evidence of any oil anywhere on the pumpkin, wheel or weep hole at bottom of the swing arm. The bike has been sitting on the centerstand in the garage since last November. I have not taken anything apart yet - figuring to wait and see if there is anything more coming out. I am past due for some rear end service (shock refurb, drive splines, u-joint and relay arm) so I will likely have it apart in the near future. People have reported leaks due to overfilling but that is not the case here.

Anyway, does anyone have any suggestion as to what I should look for?
Any particular seals? Wondering if it might be #5 or #24 here since the oil only appeared after I removed the wheel...



@Canadian FJR reported a groove worn in the coupling back in 2011, but I think that had oil going out the rear into the driveshaft housing.
https://www.fjrforum.com/threads/driveshaft-gear-coupling.135066/

Most of the other leaks have been at the shaft with oil coming out of the swingarm weep hole.

I may end out putting the wheel back after changing the tire and see if more oil appears. Maybe it didn't like sitting?

Edit: Bike has 160,000 km (100,000 miles).

 

[harper]

Are you certain it was gear oil? Viscous, same smell?

 

[RossKean]

Are you certain it was gear oil? Viscous, same smell?

Pretty sure. Typical smell although very dark - possibly mixed with grease used for splines.
I am going to check fluid volume in rear drive but not enough leaked to show a noticeable drop in fluid. Will change it while I am at it, even though I plan to do a complete rear-end service once I get my Penske shock refurbished. Only rear drive leaks I have encountered were at the drive shaft where oil was coming out the weep hole in the shaft housing.

 

[harper]

I only ask because I have been fooled by a leak that appeared under the rear brake caliper. It turned out being shock oil that ran down the swing arm and dripped onto the floor right under the rear brake caliper.

 

[RossKean]

I only ask because I have been fooled by a leak that appeared under the rear brake caliper. It turned out being shock oil that ran down the swing arm and dripped onto the floor right under the rear brake caliper.

There was nothing at all on the floor under the bike until I slipped the wheel off the rear drive splines. A few mL of dark oily liquid and nothing since. Got the new tires mounted and will reassemble in the morning. Hoping just a slow weep over a period of 5 months of no movement and cold rubber seals.

 

[Oldjeep]

Check if your vent -27 is clogged. If not, I would suspect 24

 

[RossKean]

Check if your vent -27 is clogged. If not, I would suspect 24

Check by blowing in the fill port and seeing if air comes out the vent? Not sure how it could get plugged but internal pressure could cause leakage.
Around $35 for both seals (#5 and #24) so I would probably do both if the leak continues. Maybe #12 too, while I'm at it - even though the oil seems to be coming from the output side, it has been a common source for final drive leaks.

I haven't done anything with these final drives other than lubing drive splines when I have the wheel off, occasional servicing of the shaft splines and regular changing of the gear oil. I'll have to see what's involved in accessing and replacing the seals if the unit continues to leak. Still no new oil drips after 24 hours...

Almost tempting to pick up a FleaBay used final drive - they can be had fairly cheaply but you are just as likely to get one that leaks anyway (especially if it has sat on a re-seller's shelf for a couple of years).

 

[Oldjeep]

Yeah. Air hose, very low pressure in fill

 

[RossKean]

Yeah. Air hose, very low pressure in fill

Have you ever changed these seals? I can probably figure it out from the parts fiche as long as no special tools are needed.
Had a quick read through the service manual and was not encouraged but nothing about what level of disassembly was required to just replace seals.

 

[Oldjeep]

Have you ever changed these seals? I can probably figure it out from the parts fiche as long as no special tools are needed.
Had a quick read through the service manual and was not encouraged but nothing about what level of disassembly was required to just replace seals.

No. Have not

 

[Pete-o]

I've had good luck with Ebay parts. You just need to be very selective.

Pete-o

 

[RossKean]

I've had good luck with Ebay parts. You just need to be very selective.

Pete-o

Yeah, and there are always a bunch of final drives there. Always taking your chances with parts like that - not necessarily the vendor's fault. The thing is heavy and shipping costs become a large part of what you are paying. (They might take back a leaky one, but I doubt many vendors would offer free shipping on returns.)

 

[RossKean]

Did a bunch of annual maintenance stuff, including final drive lube and got the bike out for 100 km or so. Performed flawlessly and no hint of any further leaks. Hope that is the end of it.