I just did mine yesterday. It took about 4.2 quarts, give or take a bit (I was filling from a gallon jug). 
In order to reach that hard to reach level of just below full, 
I filled it full until fluid was overflowing, then removed my hose and jacked up the rear a bit. I let a completely random amount of juice out and then leveled it off and put the plug in. 

I have learned over the years that having that  level below full is key, but as to just how accurately "just below full" you need to be..... Well I don't even know how to measure!

"Just below full" is the level you seek. 

-craig 

> On Mar 18, 2015, at 1:05 AM, sailingfc @dslextreme.com <sailingfc@DSLEXTREME.COM> wrote:
> 
> So last weekend I changed the transaxle oil on my 87 Syncro for the first
> time.  Bentley says 4.7 quarts, but only 3.2 quarts if just draining and
> refilling.  And Bentley also mentions not to fill a 5 speed transaxle to
> ease shifting, but no mention about under filling for the Syncro transaxle.
> After putting in 3 quarts, I can't feel any oil inside the fill hole.  I
> put in a fourth quart and can "feel" the oil about a half inch below the
> fill hole.  I'm guessing I could put another half quart in.  So how much
> should I really put in?
> 
> -Dick-
> 87 Syncro (Blaze)