Bad clutch pilot bearing in the end of the crank. It is dragging on the
tranny mainshaft and spinning it as well as the major part of the
mainshaft inside the tranny housing. When the tranny fluid is stiff
enough the drag of the fluid slows down the shaft and overcomes the bad
pilot bearing which is trying to spin the shaft. When the tranny fluid
heats up, it is too thin to slow down the shaft much. The spinning shaft
has the gears on it and they don't want to engage their partners when
one of them is spinning much faster than the other.

Mark

Kim Brennan wrote:
> My westy continues to have a couple of annoyances. One of them is
> (once again) a shifting problem. When the engine (whole vehicle) is
> cold, I have no problem shifting in to first or reverse. However as
> the temperatures climb (mid 30's Centigrade here in southern Ontario)
> it become nigh on impossible to get it into first or reverse when the
> engine is hot. This is especially bad in traffic when I've been
> running the AC.
>
> Let the engine cool down some and I can get it into first again.
>
> I'm puzzled by this temperature related shifting problem. I just
> don't know what to make of it. When the transmission was pulled last
> summer the rubber mounts all seemed fine.
>