There's a tapered felt washer that slides over the gearbox mainshaft and seats against the outer end of the sleeve gear...The gear and its internal bush are countersunk at the end to accept the tapered side of the felt washer...Ian
Even then you still have the starter and the gearchange to leak oil from
And I really can not see how the gearchange can become leak free , unlike the unit boxes you just can't machine a square depression & slip a quadring in there .
The other problem is the absence of any breathing for the gear box so sealing them up tight will lead to other problems.
The original design can breathe through the scroll
Hi Ian
I managed to locate quite a number of these tapered felt seals some time ago
I will be using them in my gearbox rebuilds coming up
I have some spare if anyone needs them
Correct type & shape are generally not available
Jo’b
Michael, you mention using sealed bearings but removing the inner facing seals. I can understand this with the gear change end of the main shaft to allow pass through of oil. My hand change gearbox does not have any holes to allow oil to pass from the outer case to the main body so requires oil to pass through the bearing. So in this instance both seals need to be removed.
Would it not be better to leave the seals on the main bearing at the drive end in place since these bearings are intended to be maintenance free for their life.
Regards, Lionel
Michael, you mention using sealed bearings but removing the inner facing seals. I can understand this with the gear change end of the main shaft to allow pass through of oil. My hand change gearbox does not have any holes to allow oil to pass from the outer case to the main body so requires oil to pass through the bearing. So in this instance both seals need to be removed.
Would it not be better to leave the seals on the main bearing at the drive end in place since these bearings are intended to be maintenance free for their life.
Regards, Lionel
There is conflicting debate over that Lionel. On the one hand, you remove the inner seal so as to lubricate the bearing in the normal manner. On the other hand as the bearings are sealed for life and you wouldn't remove a seal for a wheel bearing application. Why not leave them intact which would protect them from debris and double the sealing effect against oil leaks?? Ron
I was advised to remove the inner seal as the gearbox oil serves to both lubricate and crucially, cool the gearbox main bearing...The advice came from a friend who was the chief development engineer at RHP bearings (as well as a BSA enthusiast) so I decided to go with that...It's worked so far...As the bearing at the gear change end is entirely within the gearbox the presence of seals would serve no purpose in preventing leaks....Ian
Yes Ian I have always removed the inner seal, but I can't help thinking...Is it necessary? There was often a problem with Wiilys Jeep gearboxes where the oil would pump from the gearbox into the transfer box through the open mainshaft bearing. The fix was/is a sealed bearing and the one I bought had steel seals on both sides and the instruction was, to leave them intact. I also think that wheel bearings work harder than a gearbox main bearing and possibly get just as hot??? Ron
These are questions that don't have an answer...You would have to do a long term road test under similar conditions with both set ups to determine definitively which method is best in terms of gearbox bearing service life, so we'll never have the true answer I suspect...
The purpose of the modification is to reduce/stop oil leaks through the bearing and having a single seal fitted seems to achieve that OK...
Removing the inner seal gives the bearing lubrication in the way that was originally intended and IMO there seems no logical reason to change that if early bearing failure is not an issue...
At the end of the day I suppose everyone must pick the theory they prefer...Ian
