output seal Frank is FTC4939.
To instal it dead square, use the actual output flange to push it in (The mud shield will push against the seal nicely) by tightening the nut. Rempove the nut and flange again, fit the old seal and use the same method and push the seal in a few mm more so the new seal clears the mudshield on final assembly. Remove the flange and hook out and discard the old seal. Reassemble and top it up :)
JC

