oil leak bevel box

Hello!

Just some advice please. I've noticed a bit of oil misting on my rear wheel. It's very little yet it's still there....not enough oil leaks to drip on the ground. The location is close to the drain hole but the drain plug is tight and dry. I am wondering before I pull the bevel box off, could this be a vent issue or a gasket issue.

Any advice is appreciated.

Thanks!

If it's a vent issue it usually manifests as dampness and staining around the vent. If it is actual dripping or weeping the source is probably elsewhere.

Have a look at the clip that holds the brake hose and speedo cable closest to the joint between the bevelbox and the swingarm on the swingarm casting. If it appears to be leaking from there it's probably the pinion seal of the bevelbox weeping or the gearbox output shaft seal. If that is dry pull the brake caliper and wheel off and check out the big seal that goes around the wheel mounting boss.

Thank U sir I thought as much. Now, if I may request your expertise one more time. Are these the part #'s I need?

GU 90408511
GU 0538630
GU 90404558

Are these available or in the realm of unobtainium?

THX!

Not finding the second one. What is it?

First one is the big seal for the wheel mounting boss. It's an 85x110x8 Viton LP seal. The third one is the pinion seal a 45x58x7 Viton LP seal. For the pinion seal you need a special tool to remove the collar that holds it and unless you are very smart it requires splitting the bevelbox to replace.

If you do need to replace the pinion seal it's a good idea to check the preload nut isn't loose and add a couple of drops of 'Wick In' to the threads.

(Edit.) Oh, and if you're going to go and check the gearbox output shaft seal if they haven't been done yet now is the time to grease the swingarm bearings and shock linkages.

Thx Pete swingarm and shock already done.My question is.Is one more likely to B the culprit over another or is it luck of the draw??
sorry#GU05358630

Ahh! No, that bit is just the collar that crushes the front boot to prevent leaks. I've never had a front boot fail. The collar just holds the boot in place and the crush is applied by the four bolts that hold the box to the swingarm.

As to which one is more likely? Either the wheel boss seal or the pinion seal but check the top boot for leaks as well.

I had my pinion seal go bad and it leaked oil out the bottom of the shaft drive about mid way to the front.
Just trying to share some symptoms of that issue.

It's all getting up in age, 18yrs for early ones, glad to ride a Tonti.

Sorry for being a pain in the ass,not sure of the part# for pinion shaft seal.Would you be so kind as to let me know?THX

No worries.

GU90404558

Part # 3. You need the special tool to remove part # 2, well, not the G clip but the seal holding collar.

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Many thx sir