Changing air side crank seal

[Gerard De Ruyter (Twistandshout)]

Hi guys.  Have just removed the stator plate on my '69 TS250, which exposes the crank seal.  Anyone know if these can be replaced from the outside (ie, without splitting cases).  I don't have any reason to think the seal's crook, apart from it being donkeys years old.

The next part of the adventure will be seeing if can make an apaptor to fit a tm stator plate (smaller diameter apparently).

[pmc57]

It shouldn't be a problem as long as you can get the old one out without damaging the case or the bearing on the other side. They just push in from the outside anyway and usually can be done with finger pressure. Check the position in relation to the casing before you remove the old one so you know how far to push the new one in,  normally the seal sits about flush with the outer face of the casing.

A self-taping screw screwed into the mid section of the seal can provide a pull point to remove the old seal, when drilling the starter hole be careful not to plunge too deep when breaking through otherwise you may jab the bearing and fill it with drill shavings. Maybe put some grease on the drill to catch any swarf and check and clean after the seals out to remove any bits that may have fallen through.
 
While it's out you may also want to check the condition of the shaft for pitting or wear grooves where the seal runs, if there is any and it's too bad to go again a case split may be necessary.