Ford select o speed

I m considering getting a 1964 ford 971 diesel. I know ford started putting DDC select o speed transmissions in their tractors in 1963. Did the 971 ever come with a DDC SOS, or just the thousand series tractors? Feel free to chime in if you think this tractor would be good or bad. Thanks

The 971 was made through 1962 and then was replaced with the thousand series. Ford introduced the DDC SOS in Jan of 1963 so you may
have answered your own question. I have no idea of your expertise in the field of Ford SOS transmission repair. If you're not a
world-class expert in that regard it would be a good idea to identify someone who is. I have the name of a highly regarded SOS
mechanic with plenty of spare parts but it would take me some time to find it. I know of a couple of guys in Mosinee, WI who are
pretty good at it but they're getting older and I believe they are trying to sell their place. Other than that I have nothing to
offer but my best wishes for your endeavor. I should add, my father and I tried out a brand new SOS Gold Demo 871 in 1959 on our
Wisconsin dairy farm. The dealer had that tractor weighted to the maximum with NaCl and cast iron and equipped with a three bottom
14 mounted plow. The tractor did fairly well in heavy red clay alfalfa sod which would have been tough for any tractor of that
day. We were impressed by the tractor's performance but didn't fully trust the dependability of that new transmission and decided
not to buy. How right we were. For further info read about Harold Brock. Ford tractor engineer.

SOS RUN FOREST RUN!!!

In the 80's the Ford dealer here wouldn't even touch one.The only guy there that knew about them had aged out and retired.I took one apart that had stopped moving,luckily it was a sheared spline coupler.I saw one in an industrial tractor with a backhoe,but the problem in that tractor was not the transmission.It had some weird kind of cable steering on the heavy duty front axle.I think the axle had Lull tags on it.The owner told me the transmission worked fine.When he called me to fix his tractor he told me it had an SOS in it,and just assumed it had a transmission problem.The guys at the Ford dealer called them jerk-o-matics.I had one in a 3400 3 cylinder gas,with a loader,and it worked slick plowing snow.My neighbor used it raking hay for two seasons,they really liked it for that.But,they were too smart to want to own it.

Once the changeover was made to the DDC in 63, all S-O-S equipped tractors were DDC.

I pilfered below from another site from someone who seems knowledgeable.
My opinion is they are not as bad as some think.

Read the casting number on the left side. 312259 was the original red transmission. This one could be problematic. However, if it operates properly now, chances are it will for the future. If the casting number is C0NN-7006-B or C3NN-7006-B, it is the blue transmission and is likely in stellar shape if it's been given any care at all.

Thanks for everyone s help. Got him to send the casting number (C3NN-7006-B) which would mean it s a DDC. Were these any stronger than the ORC transmissions or did they just change them to give engine braking in all gears.

Does anyone have any knowledge/experience with the 4cyl ford 172ci Diesel engines?

The early Ford 4 cylinider diesel engines are known to break crankshafts and are not highly regarded.

They also produce 12%-15% less PTO HP than do gasoline versions.

The over running clutch is no longer serviced, as well as the input shaft and shift cables. I explored making new input shafts and it is cost prohibitive. If the diesel has a crank balancer it is much more reliable.

(quoted from post at 13:36:59 07/29/22) The over running clutch is no longer serviced, as well as the input shaft and shift cables. I explored making new input shafts and it is cost prohibitive. If the diesel has a crank balancer it is much more reliable.

Click to expand...

As in an external balancer? Is that something that some came with or are you saying you can add one?

Ernie D,Have you looked at this for input shaft. Be interesting to see how it holds up after 20-30 years.

https://fordtractorcollectors.com/repairing-a-select-o-speed-input-shat/

The guys who like them love them.
I had a 1966 3 cylinder 4000 with SOS.
I liked the tractor but hated the
transmission.
The SOS lovers said I didn't know how to
drive it.
Well maybe. But I have driven a lot of
things in my life. From a 988 Cat loader to
dozers to an old dragline I had, to twin
stick end dumps and 9 and 13 speed
transmissions in road trucks.
I wasn't always smooth and perfectly
proficient with them but give me a few
hours with one and I can make them work
tolerably well.
I drove that SOS for 2 years and never
learned I guess.
Put one in park and they will continue
creep a little.
They have a little pedal where the clutch
pedal normally is. Ford called it an
'inching pedal'. A yarding pedal was a
better term.
Trying to inch backwards to hook up to an
implement was Very hard to accomplish.
Some of the shifts between ranges were so
hard and abrupt they shook the fillings out
of your teeth. And using it with a back
blade to level out gravel for a garage pad
doing a lot of forward and reversing was
pure punishment.
Did I mention I hated it!
Then there is the issue of their
complexity.
It doesn't take a real smart guy to split a
tractor to replace a clutch. A little
harder but not a whole lot is taking an 8
speed Ford transmission apart to replace a
bearing or some such. The I&T manual covers
it all in 8 pages.
To overhaul an SOS the same manual takes 27
pages.
Then there's parts.
Shifter cables, torque limiting clutches
and input shafts for the pre 65 SOSs have
not been manufactured for many years. So if
you need those parts it is like the Dirty
Harry movie:
'Do you feel lucky Punk? Well do ya?'
But, but, but an SOS you can shift on the
fly the lovers say.
Hmmm, how often do I really need to do
that?
That SOS I had worked perfectly.
So after owning and running it on occasion
for 2 years I ripped it out and sold it.
Then replaced it with an 8 speed.
Like that tractor even more now and
I will never own another SOS.
Sorry this got so long but I promised the
guys on the Ford board I would lay off
hating those transmissions there.
But this is Tractor Talk board so I let it
rip.

Gear driven internal.

Added to later diesels.

Definitely an improvement but they still break crankshafts (not as frequently), and balancers also fail.

Years ag, think it was 1960 Dad was looking to my a bar mower. Local Ford tractpr dealer had one and it was monted on a jerk-a-matic and in demostratint the mower on that tractor the tractor cost him the sale of the mower. When he started to move to show the mower worked that tractor about thru both me and Dad of when it jerked so bad starting to move, Jerking like that you could not get a feel for how the mower werked. Wuld have been an 871 or 881. I only knew of one person that could ever work on one and I don't know but think he probly passed away several years ago as I think if he was still living he would be over a hundred now.

There are plenty of people that work on them. If you post where you are most likely someone will advise you of someone in your area.

I'll second what you said about SOS.
Dad had the first generation SOS on a 6000.
I'll never buy a tractor with SOS.
Run Forest Run..