I’ve done this enough times that I should know how it goes..but, brain fart today, it must be the cold..hopefully not my advancing years. :worried:
Gearbox time: The oil retaining washers either side of the sleeve gear bearing have the inner section raised on one side, does this side face the bearing or is it the other way around.
I have seen it referred to as being dished but I’m not sure if this refers to the concave or convex side. :thinking_face:
I’m using a 6205 2RS with one seal removed.
cheers
Pete
The inner part should touch the bearing, not the outer.
https://pesltd.uk/?product=24-4225
https://pesltd.uk/?product=24-4236
Mark
email (option): pes.sales@btconnect.com
I believe the outer disc should be fitted so that the outer edge of the disc lightly touches the stationary outer race of the bearing, creating a sort of seal.
The inner disc should be fitted so that there is a small gap between the disc and the outer race, allowing oil to enter the bearing.
In theory, this should work to a degree when stationary, but when running, any oil should be drawn back into the gearbox by the scroll on the sprocket boss (when gearbox casing and sprocket were new).
However, since you are using a sealed bearing (contact sealed LLU I hope), the discs will only be needed for mainshaft positioning.
I used a Contact Sealed Bearing, and now have no leaks.
There should also be
https://pesltd.uk/?product=24-4235
Mark
email (option): pes.sales@btconnect.com
I thought is was supposed to be the raised central area located against the bearing inner race, thanks for confirmation. :+1:
The problem I now have is that the recess for the washer in the gearbox case is not deep enough to accommodate the washer (0.8mm deep with the washer 1mm thick) so that the outer race of the bearing is stopping the washer rotating with the inner race once the bearing is pressed home.
(I have checked another casing and the recess is over 1mm deep in that one).
As the gearbox sprocket will press on the washer, it’s a problem.
However as I am using a sealed bearing, I have opted to use a spacer instead of the outer washer.
Bit annoying as I have found several new washers hidden in my various spares boxes…why???:thinking_face:
cheers
Pete
I'm pretty sure as Mark suggests, the dish is inside against the rolling part. Otherwise the sprocket would crush it in anyway.
As you say Pete, No need for the full flinger on the bearing which could actually interfere with the rubber seal. Even if you didn't fit a spacer, I would think that 1mm would not have any effect on the rear chain run. Most frames are out by more than that anyway :blush: Ron
email (option): ronpier@talk21.com
Pete,
I think your solution is a good one. Maybe the outer race had been spinning in the housing, reducing the depth of the recess, or maybe machining operations were interrupted by a Luftwaffe bombing raid when they made your casing? Who knows?
I'm pretty sure as Mark suggests, the dish is inside against the rolling part. Otherwise the sprocket would crush it in anyway.
As you say Pete, No need for the full flinger on the bearing which could actually interfere with the rubber seal. Even if you didn't fit a spacer, I would think that 1mm would not have any effect on the rear chain run. Most frames are out by more than that anyway Ron
email (option): ronpier@talk21.com
Yes, you can also cut the outer washer to a size that it just fits from the outside of the box and fit it at a later stage.
With that you have no risk of interference with the seal and also easy fitting of the cold bearing without having to take care of the loose washer which can slip out of the recess.
BR Michiel
While this is now academic as everyone fits a sealed bearing, it's worth noting that the Instruction manual states that the depressed face should be against the bearing.
My understanding is that Mark and Ron are suggesting that the disc should be fitted with the raised face against the bearing. If it is fitted this way round there is a 0.003" gap between the disc and the outer race, which will allow oil to escape. Now I'm not suggesting that this design of sealing was perfect, and I'm sure they leaked from new, but with a 0.003" gap there would be virtually no sealing at all.
It's interesting to note that the original discs had 2 raised sections- with a depression in between the raised sections, on one side, and only one inner raised section on the other side.
However, if the disc is fitted with the depressed face against the bearing, there is no gap between the disc and the stationary outer race, and the bearing turns easily, so there's not much crushing going on, and it will anyhow be lubricated by oil through the bearing. Hence, not a perfect seal, but better than a 0.003"gap.
I think the inner disc should be fitted with the raised face against the bearing, which gives a 0.003" gap between it and the bearing outer race, allowing oil to enter the bearing.
Is my thinking wrong on this? What do others think?
Turn it over, you have the wrong raised face.
Maybe I should have said raised inner face?
Or a picture with an arrow?
edit:
Wow, I looked at my links I provided.
Someone put the correct information their.
Mark
email (option): pes.sales@btconnect.com
Steve, i can see where you are comming from but all the gearboxes i have done have had both discs fitted with the inside depression facing the bearing giving a gap round the outer bearing race. I have also wondered about this as really there is no seal at all. Examining the washers if they were fitted the other way round as you suggest then surely there would be witness marks where the mating surfaces rubbed. None of my gearboxes i have done have had these marks, it doesn't really matter now if we are fitting sealed bearings. Both washers still have to be fitted to make sure the sleeve gear and gearbox sprocket are positioned correctly.
One another note about sealed bearings, i am just in the process of renewing a unbranded sealed bearing i fitted around 5 years ago. This bearing has started to leak even when stationary, the bearing feels fine but the seals have given up. We have had a discussion about removing the inner rubber seal but this bearing was fitted with both seals fitted. All i can say is fit a quality branded bearing i have just ordered a SKF but the question is do i remove the inner seal?