In a message dated 96-03-04 22:22:27 EST, brigstoc@astral.magic.ca (John &
Dianne Brigstocke) writes:

>
>The tranny won't shift into 4th and is very difficult to shift into 3rd. 1-2
>and reverse shifts stiff but seem ok.  This just happened last night heading
>home from up north at -10 deg C in a snow storm with glare ice on road.
>Where is spring?

Sounds like the 3-4 slider hub to me also.  Not a job to tackle yourself.
Especially if in a hurry.  With time and specila tools, you probably can.  If
you wish to try it yourself, get a used tranny to put yours back on road
while you learn.
Dennis H.