Re: Mysterious Leaking transmissions/ihc-digest V5 #113

[Kim Sol <kimsol@domain.elided>]

John, Thanks for the remarks on the transmission posting, but I would
rather defer on posting these remarks generally, because of confusion
regarding Automatic transmission types in Scouts, which I don't have
answers for. On the other hand, if someone with more experience with
automatics can affirm any of this, posting to a FAQ would be fine. Alan
mentions, for instance, that he doesn't have anything like this
arrangement on his Automatic Transmission. In reviewing the literature,
I find that International used two types of automatics, covering six
variations, which had something like a vaccum control unit, with a line
to the engine vacuum, but that one type of automatic that did not. The
T-407 (IH number) does not have a vacuum control unit, but the following
types did:  the T-39 , T-49, and transmissions that IH identified only
as 13309, 13049, and 13409, which looked to be variants of the T-39 and
T-49. These numbers applied to 1972, 1973, 1974 and 1975 models, and
possibly others. By 1978, the Scout service manuals only refer to the
T-407, which I have always assumed was the Torqueflite. Going 'way back,
to the 1971 IH "Light and Medium Duty" Truck Service Manual, it
references the T-407, 13039, 13049, and 13409. The Chilton's Manual for
1973 Scouts indicates that the the T-407 is a Borg Warner transmission
(!?), and that the T-407 and T-39 (also Borg Warner) were the only ones
available in Scouts through 1973. My 1980 Scout, which has a T-407 (Line
Ticket), the only available automatic for Scouts that year, has a vacuum
control unit, which is what failed and threw fluid all over only when in
second gear.  The Transmission guy clearly identified it as a
Torqueflite. Binder Bulletin's FAQ on transmissions only lists the
T-407, identifying it as the Chrysler Torqueflite, and mentions no other
automatics for IH's, pending further postings.

So, I have a T-407 with a vacuum control switch, but according to the
manuals, the T-407 did not have such a switch but all other
International automatics had the switch.  Our Torqueflite technician
says that he's never seen Torqueflites with that switch, except in
Internationals, and he had always thought it was odd since the
Torqueflites are designed to work without a vacuum control switch, so
why would IH add one?  We had speculated that, for some reason, IH might
have wanted a delay, or at least more engine sensitivity, in the normal
shift from second to third gears, for heavier duty applications, for
instance, such as towing and so that perhaps the "XLC" Scouts might have
had this as a variation. He was pretty reluctant to speculate as to the
hows and the whys of this, however. In summary, I could not find a
reference to a T-407 with this switch in any IH literature (so far), the
Torqueflite was not engineered by Chrysler for this switch, and it
exists in no other Torqueflite application. All other automatics that IH
used had the switch. The Torqueflite Tech had noticed it in several
Torqueflite Scout applications, however. So, it may be one of those
interesting International Harvester "quirks" where they had the
engineering talent and interest to re-engineer off-the-shelf components
to better adapt them to narrow applications, for no other reason than
they thought it was an  improvement, even if one that only an engineer
could appreciate, with no particular marketing or economic advantage to
the company. Another small reminder perhaps, that we will never again
see the likes of the International Harvester Company. Kim Sol. '80
Scout, and some others.