The maximum the Syncro tranny should take is 4.7 quarts, per Bentley
34.19.
The maximum the Syncro front diff should take is 1.6 quarts, per Bentley
39.42.
Total of these is 6.3 quarts.

These pages are from the 1980-91 Bentley.
Since you may not be able to drain fully you may not need quite this
much.
7 quarts will be more than enough, 6 will likely do.

Save a few measly bucks and buy only 6 of the expensive stuff. Fill the
tranny first, on level ground, till it spills out. Then fill the front.
Top the front off with some cheaper lube if 6 turns out not to be
enough. It most likely will be enough. I drain the tranny with the front
very raised so it comes out faster and more completely.

Mark

Jason Willenbrock wrote:
>
> i don't know why people think this is a stupid question!  i have to
> order the redline and need to tell the sales person how much tranny
> fluid i need.  I guess i will just tell them i need enough to make the
> fluid come out of the hole!
>
> come on people simple question.  what is the capacity of the SYNCRO
> tranny for fluid?  i will need some for the front case as well.  i
> know the regular tranny on 2wd is about 4L or so.  this syncro is new
> to me and before i drain the front case i would like to have the
> replacement oil on hand.  as we all know the redline stuff is pricey
> and i do not want to over order.
>
> TIA
> jason
>