Silicone sealant is factory on Syncros.  A Syncro can swim.  This is to keep
water out of the clutch.
    Seal the hole.  The clutch is vented at the center bottom.
Syncros have a small rubber plug in this location.

Jack R. wrote:

>After carefully cleaning all the "blast media" which entered into my Bell
>housing, causing the failure of my flywheel seal, and I am changing my
>manual trans input shaft seal as well. I need to ask a few questions.
>
>
>
>The new motor in my 84 Westy is from a 91 Syncro, and I noticed that a
>silicone sealant was placed around the entire bell housing, not sure if it
>was original or added later.  For those Syncro owners out there, is this
>standard procedure?  If so, I would assume it is in place to prevent
>contamination of the bell housing from the sand / dust which can come from
>heavy off-road use.
>
>
>
>Second, the hole at the top of the motor
>http://www.flickr.com/photos/77623993@N00/1262080447/ which is used, I
>believe, for Automatic application, is the "plug" still available anywhere?
>
>
>If not, is it ok to seal this hole completely, or is this used to help
>ventilate the bell housing?
>
>
>
>After seeing what dirt can do to internal bell housing seals, through-out
>bearings etc. I feel is it very important to keep it clean, to prevent
>future damage.
>
>This may be good advice to all the list members!
>
>
>
>By the way, I took apart the Throw-out bearing, cleaned ALL the crap out of
>it, and re-greased with a synthetic molly bearing grease. is that OK, or
>should I replace?  The bearing is spotless, and everything works smoothly
>again.
>
>
>
>Thanks to everyone who has provided great advice during my "little" dilemma.
>My goal is to have this back on the road this weekend, for a solid test
>drive before its maiden voyage to Buses by the Beach - Bus Boo!
>
>
>
>Jack R.
>
>N. of Detroit - 84 Westy Wolfie, currently with Trans on the floor and new
>seals going in.  Changing the oil, and trans fluid - upgrading the Redline
>MT-90 (ouch $12 a QT!)
>
>
>
>