Don't now about Syncros but  I had the problem you describe on my 5sp
with an inline VW motor..   I myself didn't realize that Jetta cars must
not have a pilot bearing...so when I swapped to a 2.0 liter Jetta block I
didn't see any pilot bearing on my old motor so I didn't install one on the
"new" one....In just a few days the input shaft seal was ruined and leaked
gear oil into my clutch....which is how I caught the leak...slipping clutch.

   I had to replace the new clutch and nothing more.. I dropped the trans,
easier than taking the motor out on my 2wd.

   The pilot bearing is tiny...but obviously important.