CL77 Oil seal replacment.

[DJM]

After almost exactly ten years use and around 8000 miles use, after a recent 'spirited' ride my hitherto oil tight CL77 has developed an oil leak from the bottom end.

I haven't investigated yet but suspect a blown oil seal, hopefully nothing worse.

My question relates to the replacement of crankshaft or gearbox seals.

In the past I've always taken out the motor and split the cases to replace seals but, as the years a roll by I'm finding this prospect less attractive. The engines now seem heavier than I remember and wriggling the CL engine out without damaging the paintwork isn't that easier even with assistance.

I've read of others just prising out the faulty seal and gently tapping in a new one, is this really a viable option that will deliver a satisfactory result.

If so, would you put in the new seal 'dry' or add some sealant or lubricant around the edge. I'm a bit reluctant to put anything around the edge as what helps it slide in will also help it come out again, unless I use a 'setting' type sealant.

What have others done in the past and has it worked?

[mike in idaho]

I use 3M weatherstripping cement. Once it dries that seal will never move.

[GregMcN]

Dennis

I can not claim to have any specific experience and I asked a similar question recently and I think the answer I got was that it was possible but splitting was preferable and the view on sealant was mixed.
On further thought though, if you had a British style vertical split crankcase the only option would be tapping it in so it must be a reasonable option.


Greg

[AlanW]

I am with you on pulling out engines Dennis, last year I replaced a crank seal on a cb77 in situ. I pulled the old one out then cleaned the case where the seal fits with acetone, then using a deburring tool made sure the edges of the case where the seal goes in didn't have a lip, cleaned again and pushed the new seal in, no lube, it needed to be tapped for a final seat and I used a piece of ally pipe a bit smaller o/d than the seal, it worked fine and cured the leak, the guy has not brought it back so I assume it's still ok.
I think if I had another I would consider using a very small amount of a sealant that sets for peace of mind.
Cheers Al.

[LOUD MOUSE]

I install the seal with dry edge and seat.
On this list are times where others have used sealant on the seal and found that seal loose in the engine suddenly. .............lm

I am with you on pulling out engines Dennis, last year I replaced a crank seal on a cb77 in situ. I pulled the old one out then cleaned the case where the seal fits with acetone, then using a deburring tool made sure the edges of the case where the seal goes in didn't have a lip, cleaned again and pushed the new seal in, no lube, it needed to be tapped for a final seat and I used a piece of ally pipe a bit smaller o/d than the seal, it worked fine and cured the leak, the guy has not brought it back so I assume it's still ok.
I think if I had another I would consider using a very small amount of a sealant that sets for peace of mind.
Cheers Al.