transmission slipping

[rhughes@domain.elided]

Hey IH pals,

Here's a story about my '75 Scout II w/ 345 and auto tranny.  I offer it
for your entertainment or edification, and I trust that if you spot errors
in my fixit logic, you will correct me.  WARNING: This is a _long_ post.

Tuesday morning, in mid-commute, I pulled away from a stoplight and felt
the transmission slipping: the engine didn't seem to be transferring power
to the wheels -- that is, lots of "rev" for very little "go".  I quickly
pulled over, put it into neutral, and verified to my satisfaction that the
engine/carb was not the problem.  Getting back in gear, I slowly got up to
highway speed, just wanting to limp to work and deal with it later.   But
it got harder to maintain freeway speeds, and not wanting to be a road
hazard, I pulled off the freeway and coasted/limped to a 7-eleven.

I checked the ATF dipstick at hot idle and it was bone dry.  Went inside
and bought two quarts of ATF and one of "Gunk" or somesuch that is supposed
to stop auto tranny leaks.  I couldn't see any obvious hemorrages under the
truck, but all I could think of was that the slow leaks had finally added
up and emptied the tranny, rendering the torque converter useless.  Put in
two quarts and made it to work with only a little slipping.

After work, the problem returned.  Put in the third quart and got on the
freeway, but the slipping returned after only a couple of minutes.  Limped
into an Autozone parking lot, and checked the ATF again.  Bone dry.  Where
the hell was all that ATF going?

I explained the problem to the Autozone guy. He suggested that the vacuum
hose that provides the "shift" signal was misrouted/leaking/unhooked/etc
and sucking ATF into the engine, where it was being burned.  I had noticed
some smoke after I put in the third quart.

So I climbed under the truck and started looking for the offending hose.  I
couldn't find anything that looked like a vacuum hose.  And since I've had
to do a lot of carb/emissions fiddling, I feel like I know my vacuum hoses
pretty well, and I didn't know of any hose that went to the transmission.
(I'd like some input on this part of the story.  Does the IH tranny (I
assume I've got a 727) have such a vacuum- signalled shift?  Where is it?

I went back in, scratching my head.  I mentioned to him that a few days
earlier I had had to pull out my speedo cable because it had suddenly
gotten really noisy.  I had just pulled the snaky part of the cable out
from the top, not unscrewing its "routing hose" from the t-case, so I
wondered if ATF was pushing it's way up the routing hose -- though I knew
that it wasn't pushing far, because it wasn't spilling out on my shoes.  He
thought that might be the problem, so I went out and re-inserted the speedo
cable, snaking it all the way in until I could feel it seat.

Bought more ATF and started refilling with the engine running.  After about
three quarts, I heard a spattering sound on the other side of the truck.
Walked over and saw ATF all over the ground, spewing out from under the
front driver's side.  Quickly shut down and peered under to find that a
rubber hose had pulled away from a metal pipe right at the front of the
truck and was spilling copious amounts of ATF.  Following the hoses, it
became pretty clear what was happening: the metal pipe ran back to the
tranny, along with another metal pipe.  The rubber hose ran up between the
radiator and the AC condensor (is that what it's called?).

I didn't know it previously, but I've got a transmission fluid cooler.  And
it's hoses were leaking.  One of them was leaking _a lot_.

I reattached the hose as best I could, filled up the ATF, and got home
without incident, but it still felt like the tranny was slipping a bit --
especially at higher rpms.  On the freeway I had to get almost to redline
to maintain my preferred driving speeds.  Uphill was tough to maintain
speed.

I spent the next day pulling the AC condenser, which I'd wanted to do
anyway since I'd already removed the rest of the AC system.  From there, it
was  a relatively simple job to remove the tranny cooler and replace its
hoses, though the new hoses seemed to be just slightly bigger than the old
ones (they slipped right on the fittings where the old ones had been real
hard to pull off -- anyone else have this problem when buying hoses --
suggestions? I took the old ones in as examples, and the new ones looked
right), so I double-clamped them.

I refilled the ATF, and things are okay now, I _hope_.  Unfortunately, I
haven't really had a chance to drive it much yet, so I don't know if that
subtle slipping is still there.  If it is, I'll probably be back, but here
are some other questions for the meantime:

When I made my first emergency ATF refill, I carelessly pulled Type F off
the shelf (I'm supposed to use Dextron (or is that Mercon) III, right?).
There are two quarts of Type F in my tranny -- though I hope at least some
of it is on the Autozone parking lot.  Is this a big problem?  Do I need to
change all the fluid right away?  Will it cause any damage?  I drove
probably 40-50 miles since I put it in.

Is low fluid the only -- or the most likely -- cause of slipping?  Might
there be another, more serious problem?  Might another problem have created
abnormally high pressure, causing the leaks in the first place?

Does my tranny (it's stock on a '75, so I'm pretty sure it's a 727) have a
lockup torque converter?   Is there a way to tell if it isn't working?
Would it's function be related to any of the above issues?

Would pulling the speedo cable have anything to do with my problems?  As
I've thought about it more, it seems like it wouldn't.  The t-case and the
tranny don't share fluid, do they?

Is there a vacuum signal hose for the tranny?  Where?  I'd like to check it
if there is one.

Can I use some type of goop on the rubber hose-to-metal pipe fitting, to
further reduce the chance of leakage?

The tranny cooler is now sitting out in front of god and everybody on the
front of the radiator, unprotected by the AC.  Suggestions on protecting
it/making the grill look cleaner with a dark screen-type material behind
the grille?

Is the tranny cooler stock? (It's a rectangle about 10" x 5", with a
w-shaped pipe threading through fins)  Is it sufficient?  Suggestions on
upgrading?

Sorry for the long post, but it's my nature to include every detail,
because I'm afraid of leaving out something potentially important.  All
thoughts would be appreciated.

Rob