Different transmission configurations

[Truck Shop]

So what about sub-transmissions?

You mean Main & Auxiliary. Those can still be bought/ordered, but no one does because
those require some memory people don't want to use anymore, plus the design of those
was because 220 HP was about all that was available in big power in the 30's,40's 50's &
early 60's. With the power of todays engines there just is no reason. 4x3, 4x4, 5x3, 5x4 &
6X4 were the common. Like I said before a 9 spd & 4 spd 2141 auxiliary makes a great
combo. With any set-ups like that the aux is left in direct in many cases just using the 9.
But it gives a bunch of low gears when needed using deep under/under, the in high range
on the 9 you can split the top four between direct and over. All of this provided its a
progressive ratioed auxiliary.

 

[MG84]

You mean Main & Auxiliary.

Yes that's word I was looking for. That C65 may have been a 5x3, can't remember, had a 427 so no powerhouse in a tandem.

On the other end of the spectrum, I sometimes see a fairly heavy truck with only a 5 or 6 speed transmission. There was an L9000 tandem semi tractor for sale a few months back with a Detroit (can't remember, either 6V92 or 8v71) and a 5 speed?!?!

 

[63 caveman]

Installing clutch--I install with clutch loaded on the transmission input shaft-clutch fork
hooked over T/O bearing. With the wood/plastic T/O bearing retainer/depression left
in place. Only the input shaft has to be lined up with pilot bearing--goes right together.
Install all bell housing bolts, Looking through clutch inspection hole line clutch cover
with bolt holes in flywheel. Using a long extension and a pry bar to tip/lift the cover
slightly start a bolt go to the next start it, bar engine to next set of bolt holes in clutch
cover start those and repeat till all eight are started. Then gradually run them down baring
engine. Torque to 55 Ft lbs. As you do this the wood blocks installed on new clutch will
become loose and normally fall out, sometimes you have to knock them out with a bar.
Hook up linkage and set/ adjust clutch, normally it's pretty close with turned flywheel.
*
Reason I do it this way is it's easier than trying to push the transmission input shaft
through the two clutch plates, and it stops the possibility of a clutch plate getting
damaged from installation--it happens. The other reason--it saves getting hurt lifting
if no clutch jack is available. And this can only be done with the 15" clutch not a 14".
*
View attachment 309066View attachment 309067View attachment 309068View attachment 309069

Never heard of this before! I'm going to try that next one I do. I'm getting older and those dang things are getting heavier!

 

[Truck Shop]

Never heard of this before! I'm going to try that next one I do. I'm getting older and those dang things are getting heavier!

I haven't installed a 15" clutch on the flywheel first in what must be 40 years. Sometimes
when you know the clutch isn't old but is having issues of one sort or another, clutch and
trans can be unbolted slid back as a unit. Just enough for clutch to clear bell housing.
Drop the jack slide the old clutch off slide the new clutch on back up & back together.
Works well when space is limited, with some help to lift clutch cover of coarse.
*
Always liked the Cat powered with baring tool ports on both sides of rear structure. I used
the right side because I could stay on the creeper. Normally I would have someone help
bar engines over.

 

[Truck Shop]

There was an L9000 tandem semi tractor for sale a few months back with a Detroit (can't remember, either 6V92 or 8v71) and a 5 speed?!?!

Detroit's followed by a gear box with minimal speed selection is usually a Allison slush box.
Detroit's don't like to be lugged--well neither does a Cummins or Cat. But MacK the Crack
like to put their famous 5 speed behind a Maxidyne's and such. You could always tell a Mack
that had one, lugging, smoke poring out the stack, along with that Mack drone of straining
at the bit trying to pickup road speed all the while the driver with his right foot just mashing
the floor. Mack lovers rave over them--it gave them more time to reach for a Little Debbie
Snack between shifts.

 

[cuttin edge]

Yes that's word I was looking for. That C65 may have been a 5x3, can't remember, had a 427 so no powerhouse in a tandem.

On the other end of the spectrum, I sometimes see a fairly heavy truck with only a 5 or 6 speed transmission. There was an L9000 tandem semi tractor for sale a few months back with a Detroit (can't remember, either 6V92 or 8v71) and a 5 speed?!?!

Nothin like the sound of a good working gas job. Not many left

 

[MG84]

Detroit's followed by a gear box with minimal speed selection is usually a Allison slush box.

This definitely was a manual, straight shifter coming through the floor, just a regular little shift knob (no splittler, range button,etc). Description said 5spd, could have maybe been a 6 but IDK. Was for sale in Kentucky, looked to be owned by a farmer. Don't know if it was factory or if someone had been swapping stuff around, but looked like an absolutely terrible combination to me.

 

[56wrench]

My brother had an old ‘74 Chev 70 series with a Detroit 6V53, an Allison MT650 and a Spicer 7041. Was originally specced for a power company auger truck. I’ve never seen another one like it. On a further note, that little air button for the trans/clutch brake was also used by GM gas jobs with a small 13spd in about 1978. I drove one with a 454. It had a little more torque than a 427. They were quite rare around here

 

[terex herder]

I've not seen a low deck big block in a factory GM truck. I know a couple of guys that claimed them, but a quick glance showed they were tall decks.

 

[56wrench]

This was a tall-deck 454. Not many made according to the GM parts guy at the time

 

[Truck Shop]

The trouble with most auxiliary boxes was the direct/over split, an example the old 8341
came in several ratio varieties. the best were progressive. The 1241 progressive was a
good auxiliary even splits all the way through. I drove a 77 Freightliner 86" cab coe that
had a 12V71 and 5x4 progressive 3 trips to the markets in California. Coming back north
up I-5, first Dunsmur Canyon before Shasta and Ashland in the Siskiyou's it would flat
pull. Wind it to 2200 come back in at 1800 plus. But it was tiresome in heavy traffic, plus
the constant scream of the salt water chevy was endless.

 

[cfherrman]

Untill recently, because hydraulics, people would use aux transmissions for the ptos for winches, put the main in a gear and the aux in neutral and kick in the PTO, many speeds to choose from.

 

[Truck Shop]

Untill recently, because hydraulics, people would use aux transmissions for the ptos for winches, put the main in a gear and the aux in neutral and kick in the PTO, many speeds to choose from.

Yes that's gone on for a long time. Plus the power tower.

 

[cfherrman]

I'm guessing a power tower is a transfer case?

 

[56wrench]

Some old winch trucks used a 13spd main and a 3 or 4spd auxiliary. Around here the power tower was the whole top cover for the auxiliary with the gear drive for the winch included a F-N-R selector. If i remember right, the power tower was driven internally off the drive gear on the auxiliary transmission input shaft

 

[Truck Shop]

internally off the drive gear on the auxiliary transmission input shaf

Correct.