main crankshaft bearing seals

[rcpeddie]

hey everybody, should the crankshaft bearing seals, left and right be changed often??...you know with air being sucked in one side or oil from the clutch side. I have the top end off and was wondering about just going ahead and pulling the rest of the bits off to get them. Surely I can change the seals without splitting the cases?
thanks to all of you for this great forum

[nola_fiddy]

It's a good idea to change them out if they are getting old - like several years old at least. As far as splitting the case to get to them - it depends on the bike CR's don't require a split but KX's do. I'm not sure of every make and model.

[MXtras]

Usually, the seals will outlast the bearings if the engine is properly lubricated. If your bike needs seals, it's very likely it needs bearings, too. Excessive clearance in the bearings is normally the reason the seals start to leak in the first place.

There are always exceptions, of course, but it's something to think about.

Scott