[VAC] Synthetic transmission oil

[Jack Honeycutt <jhoneycutt@xxxxxxxxx>]

Reading between the lines in Trailer Life Magazine, I got the impression 
that transmissions in tow vehicles would run cooler (and maybe perform 
better, or at least last longer) if the transmission oil was switched to a 
synthetic.

So I took my 1972 pick up to the local, old time transmission place in town 
to let Crusty, the local expert, drain out the transmission oil, replace 
the filter, and fill it up with a synthetic. Well, Crusty though I was 
nuts.  He said that the synthetic would leak out of my transmission and was 
no good anyway.

I ended up going to another transmission shop and having the transmission 
oil replaced with the original transmission oil (not a synthetic).

My issue is heat.  I do have a transmission cooler on my truck.  Should I 
just run the original rated transmission oil in it and call it good?  Or 
will the cooler running synthetic come in handy when I am haling a heavy 
trailer up a mountain?

Jack in Oregon