My gearbox has a black rubber bellow on the back of it that is supposed to expand and contract with changes in pressure. As @JarJarJava described it, it looks “like a mini French tickler anal stimulator.” I can’t say I’m an expert in that department, but there is a good chance after 14 years the rubber on mine is not as flexible as it needs to be to deal with the changes in gearbox pressure. However after taking it off and inspecting it, it seems very serviceable (it’s pliable and there is no cracking or dry rot to it).
Nevertheless, I’ll see if I can find a new one. If not, I’ll replace it with a section of clear hose and form a loop. My gearbox will no longer be sealed, but it will definitely be sufficiently vented.
I spoke with @Old_Houseboater offline last night and he said the reason you can’t use the sealed bearing in conjunction with the ring seal is the sealed bearing prevents the oil from getting to the ring seal and it will quickly burn up. Makes sense. He also said the way I installed the ring seal was correct.
Come to think of it, I wonder if replacing the bellow on my gearbox when I was having the minor seepage on my original spline shaft would have fixed the problem. When I removed the original shaft, the bearing still spun nicely and the teeth on the shaft were pretty decent. Never thought to try that.
I removed my brand new spline shaft (on the right) and compared it with my original (left). The old one has a sealed bearing and therefore no lip for a ring seal to seat against. The new one has that lip because it uses an open bearing and requires a ring seal. The old shaft is slightly longer with a total length of 119.42 mm while the new shaft is 118.9 mm. They are within .5 mm which seems perfectly reasonable.
However when you look at the new shaft, you can see the ring seal, which is 6mm thick, is essentially double the width of the metal lip it seals against. Is that how it’s supposed to be? It seems odd that half of the ring’s sealing surface area is being taken out of the equation. Any thoughts?
What do you think @Old_Houseboater?
IIRC, my 02 gem diff had a tube arrangement simillar to what @js9354 posted. I never did shoot thermal images of the diffs after being driven around, but i don’t think vented / non-vented w bellows is that big a deal unless you live somewhere that has a constantly high humidity.
Btw, i just realized i got you to post mini french anal tickler and your handle is “sniff”. hurhurhur (bevis laugh)
The end of the seal surface should be almost square, the radius robbed 2 mm of length and this is where the seal rides. It only costs me 15 bucks more to use the double sealed bearing in my kits, Which is what I will supply in the future. You did everything right. Extremely sorry it happened.
Your leak came from a sealed bearing that expired from old age. the KOYO bearing was a FULL CONTACT sealed bearing that they discontinued due to lack of demand. I have sourced a Double Contact bearing that is a performance plus equivalent and which I will use in my kits going forward. A garden variety 6005RS bearing that is normally sold by everybody is a NON CONTACT shield bearing and will LEAK
@js9354 — How does your gearbox vent tube terminate? Is the hose open to the atmosphere or does it have a filter or some other type of device at the end?
What this CONTACT and NON CONTACT stuff means is the seal either is fully in-contact(sealing) with the grooved the inner bearing ring. NON CONTACT means there’s no seal with the inner surface/ring even if there are covers on the bearing.
Contact is a sealed bearing, Non contact is a “shield” bearing. Fully 95+ percent of bearings are “Shield” bearings. HOWEVER when you go to buy a bearing you get a shield bearing unless you specify a full contact SEAL
