Hi,

I have a 1995 F150 with 4speed OD 2x4 ...

I was towing my 17' runabout boat up the mountains this weekend (with
a load of wood, camping stuff in the bed too), and it appeared the
transmission was slipping pretty bad, while going up a steep, dirt
grade.

Upong further inspection, the transmission oil seemed fine, and then I
noticed while the driver selector is in (D) that everything is fine.
I always turn off the O/D selector while towing.

So, while the selector is in 1 and 2, it slips, but in D it doesn't.
There was a smell of burning in the cab as well.

Is this a clutch problem?  Not too keen on the inner workings of an
auto tyranny.  I figure it needs to be pulled out and rebuilt no
matter what.  I'm now deciding on having it rebuilt at a shop, or
going with one of this online outlets and having it shipped to me, and
installing it myself.  I hear it's pretty easy actually, just a couple
bolts, some strength, and maybe a buddy or two.  But no clue yet.

Any suggestions?  Ideas of what exactly is happening? Options of
places to buy the rebuilds?  I think it's a 4R70W transmission??

Also the oil and water temp seems to climb close to scary while on
pretty steep hills.  Is this normal?

..Nate