4t10 vs 4t12 thiokol trackmaster

socal4t12 · Sep 22, 2007

can anyone shed some light on a rumor. ive got a 1961 thiokol trackmaster (serial# 183) that im rebuilding. i was told it was 1 of 12 that were specially built for the USAF( called a 4t12). the custom build on it was that it had the Borg Warner T-87 tranny along with twin Dana 70 rearends.
there was remnants of the correct USAF blue paint, as well as some very faded stenciled markings on the doors. the tranny and rearends came with it, but was told that the rearends were custom built after the originals. no brackets are attached to them, so i have no way of knowing how they should attach.

anyone with info, please help.

Snowcat Operations · Sep 22, 2007

I am unfamiliar with the 4t12s or the 10s. I would contact Peterson Equipment out of Utah. Ask for Steve. He may have even built your very unit when it came of the factory line.

Mainer · Sep 24, 2007

socal4t12 said:
can anyone shed some light on a rumor. ive got a 1961 thiokol trackmaster (serial# 183) that im rebuilding. i was told it was 1 ...
anyone with info, please help.

I think you should also check with Peterson's on the transmission question...I thought the drop-boxes as stated were standard across the Trackmaster line but maybe not.

The documentation I have only shows 'officially blessed' models as:
4T2N/W, 4T4N/W, 4T8N/W, 4T10N/W so the '12' may be just as you stated as a custom request with more seats...although I can't see a huge amount of room past the '10' but maybe everyone wasn't as fat as the national average is now. :pat:

Where the N and W are physically different models based on the width of the chassis as it was used to obtain the right 'float' to suit the conditions. The chassis was either 'Narrow' or 'Wide'. Wide was for bare-ground conditions with narrower tracks while the Narrow was just the opposite...snow with wider tracks.

So, the 4T10 design ground pressure is 0.78 psi while the 4T2 is 0.68 based on empty weight. Weight of the 4T2 is 4410 and the 4T10 is 5060. Length of all the Trackmasters was 142" so that would be the interesting 'acid test' on yours as a 'Limited Edition' ...is it actually longer than 142"? Distance betweeen the front and rear axle is 90.5". That would be interesting if they actually made an extended length cab. If it's the same 142" then it sounds like they squeezed in a midget or two. :pat:

Internally, the only way I would see this happening is if they shortened up the fuel tank but I can't see that (standard 19 gallons) so it would seem that it would have to be a 'stretch' version.

Anyone else have info on the trany?

Here's a shot of my 4T10 back-end as original.

Mainer · Sep 24, 2007

On another note... I've found now a THIRD chopped up 601. How horrible.
It's like coming across a buck turned into roadkill. I'm sure whenever and whoever did the conversions thought they were doing a wonderful and creative thing. Ridiculous. Seems they make the cut just before the fuel-fill and then reuse the aluminum in the back to close up 'the hole'.
Turning nice 8-12 passenger 601s into 4 person rigs.
I know... to each his own... but from a historical/classic perspective it really sucks. Let's see...how many groomers are out there vs. people-mover cats?????

socal4t12 · Oct 31, 2007

Mainer said:
I think you should also check with Peterson's on the transmission question...I thought the drop-boxes as stated were standard across the Trackmaster line but maybe not.

The documentation I have only shows 'officially blessed' models as:
4T2N/W, 4T4N/W, 4T8N/W, 4T10N/W so the '12' may be just as you stated as a custom request with more seats...although I can't see a huge amount of room past the '10' but maybe everyone wasn't as fat as the national average is now.

Where the N and W are physically different models based on the width of the chassis as it was used to obtain the right 'float' to suit the conditions. The chassis was either 'Narrow' or 'Wide'. Wide was for bare-ground conditions with narrower tracks while the Narrow was just the opposite...snow with wider tracks.

So, the 4T10 design ground pressure is 0.78 psi while the 4T2 is 0.68 based on empty weight. Weight of the 4T2 is 4410 and the 4T10 is 5060. Length of all the Trackmasters was 142" so that would be the interesting 'acid test' on yours as a 'Limited Edition' ...is it actually longer than 142"? Distance betweeen the front and rear axle is 90.5". That would be interesting if they actually made an extended length cab. If it's the same 142" then it sounds like they squeezed in a midget or two.

Internally, the only way I would see this happening is if they shortened up the fuel tank but I can't see that (standard 19 gallons) so it would seem that it would have to be a 'stretch' version.

Anyone else have info on the trany?

Here's a shot of my 4T10 back-end as original.

just looked at my dash plate,,,,,my over all length is listed at 151". the width is listed at 93.5". height is 89".
my manual shows the following info: length-142", width-94", height-84",,,,,,,,maybe ive got a special edition.

Snowcat Operations · Oct 31, 2007

What do the 601s weigh in at?

Mainer · Dec 24, 2007

Snowcat Operations said:
What do the 601s weigh in at?

The overall stats for a 10-passenger 601:

Weight=5,460
GVW=7,460
Wheelbase= 99" nominal
Tread= 65.25"
Wheel size=15x3, 6 bolt
Tire size=6.50/6.70 x 15, 4-ply
Track width=32"
Fuel=25 Gal
Fuel consumption=4-8 MPG
Top speed=35 MPH
Dimensions:

Length=161"

Width=97.25"

Height=92.375"

That's right... look at those dimensions... 36-25-36! :boobies:

4t10 vs 4t12 thiokol trackmaster

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