Re: Dualmatics, More on the T-407.

[Kim Sol <kimsol@domain.elided>]

Regarding the different hubs IH used.  Our 1963 IH 3/4 4x4 has
"Dualmatic Hubs -- Longmont, Colorado" on it.  They have two levers that
swing out and then rotate in opposite directions and the slip back into
the protective slots, to engage or disengage the front hubs. They've
always been real easy to work with and survived much hard work. We've
always used that pickup for heavy hauling and pulling disc and harrows;
putting in fence, stretching wire, chasing cows, being chased by bull,
etc.. Never could find the particular mechanical counterpart in any of
our IH Service manuals, but it seems to me that Missoula Truck Sales
told me years ago that they were a dealer option, and that's why they
say "Longmont, Colorado" under the name Dualmatic.  They are a big tough
locking hub.

As to the T-407 transmission.  A little more background. Two types of
T-407 were indeed found in IH products: a full throttle kickdown model
and a combined part throttle and full kickdown throttle model. The part
numbers suggest that there were even more variations contained within
those two model types. The part throttle transmissions had part numbers
423977-C92, 423978-C92, 423979-C92, 423980-C92, 42381-C92, 426210-C92,
441272-C91, 441273-C91, 441271-C91, 441275-C91, 441276-C91, 441277-C91.
The full throttle transmissions had part numbers 423976-C91, 423976-C93,
423977-C91, 423978-C91, 423979-C91, 423980-C91, 423981-C91, 426210-C91.
The Truck Service Manual for 1972, which covers light line and medium
duty warns in the T-407 section, "transmission operation requirements
are different for each vehicle combination and some internal parts will
be different to provide for this.  Therefore, when replacing parts,
please refer to the nine digit part number stamped on the left side of
the transmission oil pan."

So, at least in the early 70's, there were two basic models of T-407,
Torqueflite transmissions, with a combined total of 20 variations of
those two models. By 1979, three T-407 models remained for the Scout
line, 492448-C91, 492448-C92, and 492449-C91, carrying the same warning
as above that different requirements mandated different internal parts,
"please refer to part number stamped on the side of the transmission
pan." All of these appear to be variants of the part throttle/full
throttle kickdown model, and these appear to be different, again, from
the earlier versions of that same model judging by entirely different
part numbers. However, I do seem to recall that IH changed a lot of part
numbers in 1978 or thereabouts, and these may have reflected only a
renumbering rather than new variations.

Kim Sol, 1980 SII 345, 1975 SII 304, 1972 SII 304, 1964 C-1100 4x4 304,
1963 3/4T stepside shortbox 4x4 304.