L1500 Rear Main Seal

[aussiejeff]

Hi All,
I split my tractor six months ago and replaced the rear main seal, all has gone well with 50 odd hours since the repair but now i have an oil drip again and i am thinking the new seal has failed. Apart from just bad luck is there any other reason a main seal may fail? Any help will be appreciated, thanks.

 

[GeoHorn]

I’m sure you examined the crankshaft-journal where the seal “rides” for damage…which would be the first thing I’d think of….

When replacing a seal like that it’s sometimes suggested to take some (180-grit) emery-cloth and “wipe” the journal to create minute scratches (in a helix pattern in the direction of rotation) that will encourage oil to return to the sump rather than escape via the seal.
Here’s an illustration of such a method used on aircraft engines: