Timken Rear Main Seal 195.6

I've never had one fail completely, just tried replacing one in a near (or over?) 100K engine once and it didn't help much, so had to go back and do it again.... which was better. Second time I just replaced the lower and packed the top with a brass punch, cutting small pieces of another seal and packing those in also. Still "marked it's spot" after that, but didn't coat the clutch any more. That was the first one I ever did. Had better luck on a couple rebuilds later, but they always left a little spot. No more than a friend's Harley though...

I've had a couple that didn't leak enough to "mark a spot" -- all had never been rebuilt. Don't know how the factory did it, but installing a rope seal is a lost art for sure!! At one point I looked for a neoprene seal that might be adapted. The area of the journal where the seal rides is the same diameter as the bearing journal, IIRC. I never did find another engine with a close enough journal diameter, but only had some Chilton's manuals to search... and I didn't look for long.  Even if the block and bearing cap needed some minor machining it would be worth it for rebuilding. I was hoping to find something that would fit the groove with some trimming of the seal and/or shimming in the groove.