Cush drive / drive side oil seal

[spottycat]

Hi,

Continuing my work but having trouble finding the correct seal for the drive side. I ordered part no' 57-2187 from Dragonfly as it was listed as the drive side oil seal but clearly not the right one for my 1961 A10. Having fitted a new roller bearing, I think the seal I need (assuming what I took apart was correctly installed by the last person) is a seal that fits into the crankcase and seals on the outer of the cush drive spacer. The picture shows how I have fitted the old seal around the spacer (but the rubber seal is perished and split so needs replacing). The second picture shows the cush spacer, the seal and beside it is what I bought but is way too small. Does anyone know the correct part no' for the seal that I need? I have looked at all the exploded diagrams on Dragonfly site but am obviously overlooking it.

[chaterlea25]

Hi spotty,
Typical service from them
Have you asked Andrewat Priory magneto?

If you have an local industrial bearing / seal shop take the old seal there and see if they have one.
I think the originals had a steel outer shell but the modern one will be fine.

John

[berger]

spotty cat make sure you put that collar that the seal sits on with recess to the crank bearing .

[Swarfcut]

   This should be the simplest of fixes. You need the correct seal, correct spacer and the correct drive sleeve. The problem with all old bikes is whether these bits are as they should be or a previous owner's failed attempt.

 The seal should not be a problem, plenty available online. I do not think it is a widely available "Industrial Standard" offering, rather a BSA special, so an exact match to original may not be available from your local bearing supplier. I'd try Priory Mags, as suggested.

 As with bearings, the dimensions of shaft, housing and width define the size, followed by the type of seal lips. Fit with the spring facing into the crankcase, it just pushes in onto the bearing outer race. Factory usually gave the case a few punch indents to make sure it stayed in place.

 Fit the spacer with that relief chamfer facing towards the crankcase. This means the spacer does not bear on the relieved change of diameter in the crank at the bearing position. That's wot bergs said (see previous post) while I was typing this.

 I've always fitted the seal, then the spacer. Anyone any thoughts on fitting seal and spacer together.?......I wonder if the spring always stays in place doing it my way.

 Swarfy.

[spottycat]

spotty cat make sure you put that collar that the seal sits on with recess to the crank bearing .

Sorry, not sure I followed that description.

[spottycat]

Hi spotty,
Typical service from them
Have you asked Andrewat Priory magneto?

If you have an local industrial bearing / seal shop take the old seal there and see if they have one.
I think the originals had a steel outer shell but the modern one will be fine.

John

Thanks but there are lots of these bikes about. Surely they are available to buy - I just haven't found the right part no'

[Swarfcut]

   Just had a look on Drags. Sure enough the seal you want is not easily found (if at all) considering it is a commomly required part. Thus endorsing CJ's cryptic comment.

   Have a look in the Forum Literature Section where the parts catalogues are available to view. Once identified by part number, a google search should bring it up. Ebay also has a good few offered, one especially fits the size criteria, but has a circular lip that extends forward of the face of the seal housing. This may foul on the rear of the drive sleeve and is best avoided as it will be a standard seal not a BSA special. The others look OK.

  Meanwhile, looks as if 57 2187 is more at home on a Norton Atlas or Dominator.   67 0674 is the BSA Seal you need, according to Feked, so it may or may not be true. Just saying....

 Swarfy.

PS If the seal 57 2187 was sent in error due to an incorrect description, reckon you have good cause for a refund. Good Luck With That,  eh, CJ.

[berger]

spottycat  the steel ring the seal sits on must have the chamfer / recess facing the crankshaft bearing , ebay item number for the seal is 116236998230.

[CheeserBeezer]

Hi spotty,
Typical service from them
Have you asked Andrewat Priory magneto?

If you have an local industrial bearing / seal shop take the old seal there and see if they have one.
I think the originals had a steel outer shell but the modern one will be fine.

John

 I stock those and I have used spares of all the bits that fit on the crankshaft to make up the cush drive.

[RogerSB]

Here's a couple of pics.

[Swarfcut]

 Thanks Roger, a picture or two is worth a thousand words. 

   Seal fits flush against the crankcase face, punch marks visible and seal and spacer fitted in the right way round, better pictures than my greasy old Haynes Manual.

  See that witness mark halfway along the crank spline?  That's where the end of the inner spline of the drive sleeve ends up.  Without that cush nut being nice and tight, fretting on the splines by the drive sleeve will wear a distinct step on the crank splines, something to look for on any used crank. With a step it will be impossible to clamp the sleeve, bearing inner race and shims tight against the crank web, as the sleeve bottoms hard on the step rather than the  inner race. So get that nut up good and tight to stop it happening in the first place.....plenty on the Forum already.

 Found you have a step?  All is not lost, there is a simple hooligan trick which I've detailed somewhere in Forum posts.  PM me if you have this problem and I will talk it through as it's not for the purists.

 Swarfy.

  .

[RogerSB]

I remember having to shim between the distance piece and the engine sprocket to get the engine sprocket and the clutch sprocket to align. I can't remember exactly how much, but I know it was more than one shim. I even have a note made at the time that BSA 67-2058 is 0.030” and BSA 67-2057 is 0.010”. but didn't add which ones I used. So probably a combination of both. I know I was a bit concerned about having to use more than one shim, but as it was all held up tight by the cush drive nut I thought it would be ok. That was some years ago and (as far as I know) it's not been a problem.
Rog.