damaged crankshaft oil seal face?

[Scooterslag]

I was removing the bearing collar by dremeling a notch in the collar and using a chisel to tap it off when I slipped and scuffed the taper,



as you can see where I've circled the scuff - its quite near the flywheel side seal, its not a deep mark but you can pick it up if you run your fingers over it, is it knackered and would damage the seal or could I smooth it down and use it? thanks Paul

[Jim Rose]

If it's in the space the seal face takes up you'll have to bin it. If it's outside I'd use it

[coaster]

I agree with Jim, I'd have a measure up to be certain but if that dark line is where the oil seal runs it will be fine. Masking tape next time lol

[Phil D]

I wasn't brave enough to remove mine that way .
I found welding an old bearing on then 3 leg puller -works really well.

[Tractorman]

The black line around the shaft looks to be the oil seal track so you will be fine. Polish up the damaged area with oiled fine wet&dry. You can protect the oil seal tracks with jubilee clips whilst getting the bearing track off. I use a grinderette to remove the bearing track by grinding away the track and just before you are down to the crank you will see the track heat up. The track can then be removed easily with an hammer and punch.

[HxPaul]

The part you have scuffed is in a recess and I cant see the oil seal running in there.

[Scooterslag]

ah it can be rescued, great, thanks for the replies Paul

[Warkton Tornado No.1]

I was removing the bearing collar by dremeling a notch in the collar and using a chisel to tap it off when I slipped and scuffed the taper,



as you can see where I've circled the scuff - its quite near the flywheel side seal, its not a deep mark but you can pick it up if you run your fingers over it, is it knackered and would damage the seal or could I smooth it down and use it? thanks Paul

Sorry for the late response.

If it were me, I’d clean up the whole of that diameter by hand, very carefully, remembering to try & keep the whole face concentric.

However, if you have access to a lathe & tape up the conrod so that it’s not flapping about, it would be best done that way, between centres. If that is the case & the pit is deep, you could get a sleeve put on. In such circumstances, it’s very handy to have a mate that works in a machine shop...

When I say cleaned up, any obvious pit needs to be gone.

Then the surface needs to be the correct roughness!

Oil seals will fail quickly if the surface they run on cannot retain oil. Similarly, too rough & the lip will simply be worn away.

Then, a brand new seal should cope if the remaining diameter is not too small. Look in a good seal manufacturer's catalogue & you might even find a seal with twin lips. Oooer!

Failing that, there are a number of options in selecting a very close imperial size oil seal.

Having said all of the above, remember that the seal is not the primary seal that ensures crankcase (bottom end) sealing. It is ‘only’ for the magneto bearing so retains just the grease, so as long as you use a good, high temperature type, it shouldn’t all escape even if you end up with a small weep.

I hope you can understand my waffle & it helps you

[Scooterslag]

I was removing the bearing collar by dremeling a notch in the collar and using a chisel to tap it off when I slipped and scuffed the taper,



as you can see where I've circled the scuff - its quite near the flywheel side seal, its not a deep mark but you can pick it up if you run your fingers over it, is it knackered and would damage the seal or could I smooth it down and use it? thanks Paul

Sorry for the late response.

If it were me, I’d clean up the whole of that diameter by hand, very carefully, remembering to try & keep the whole face concentric.

However, if you have access to a lathe & tape up the conrod so that it’s not flapping about, it would be best done that way, between centres. If that is the case & the pit is deep, you could get a sleeve put on. In such circumstances, it’s very handy to have a mate that works in a machine shop...

When I say cleaned up, any obvious pit needs to be gone.

Then the surface needs to be the correct roughness!

Oil seals will fail quickly if the surface they run on cannot retain oil. Similarly, too rough & the lip will simply be worn away.

Then, a brand new seal should cope if the remaining diameter is not too small. Look in a good seal manufacturer's catalogue & you might even find a seal with twin lips. Oooer!

Failing that, there are a number of options in selecting a very close imperial size oil seal.

Having said all of the above, remember that the seal is not the primary seal that ensures crankcase (bottom end) sealing. It is ‘only’ for the magneto bearing so retains just the grease, so as long as you use a good, high temperature type, it shouldn’t all escape even if you end up with a small weep.

I hope you can understand my waffle & it helps you

Thanks for that Warkton Tornado, always a good source of useful information. Paul