select-o-speed or 8 x4H/L?

gears · Jan 29, 2015

Is one of these preferable to another for a late 60s 3000/3400 that's going to be used for hauling firewood, box-scraping and moving dirt around the property?

beginning to think my 3400 gas with a bad motor might be better as a parts tractor and the runner I've stumbled upon is a S-O-S.

Dean · Jan 29, 2015

I'm partial to the S-O-S but either would be fine for your tasks.

Dean

RickB · Jan 29, 2015

You won't find an 8x4 in a 3000 or 3400. 8x2, 6x4, 4x4, 6x2, 4x1 would be the manual transmission options.

gears · Jan 29, 2015

Anything to watch out for with an sos?

Also, I'm unclear what exactly an sos is? I understood it to be variable semi-automatic....

old · Jan 29, 2015

My self I do not like the SOS due to greater maintenance cost and time doing so. If not maintained they can become a money pit very fast. But then I also do not like an automatic in a car or truck. Now a standard in any combo that is what I will look for. Yes I have had SOS tractor but those where fix and get rid of fast

gears · Jan 29, 2015

Thanks Rick, that's what I'd meant - 4 gears H and 4 gears L

so the SOS is like an automatic - does it use a torque convertor too?

Texas! · Jan 29, 2015

(quoted from post at 01:33:53 01/30/15) Anything to watch out for with an sos?

Also, I'm unclear what exactly an sos is? I understood it to be variable semi-automatic....

The SOS is NOT an automatic and it has no torque converter. It has a dry clutch just like a standard trans but that clutch is a Torque Limiting Clutch that is designed to slip when overloaded. The SOS is like an automatic in that it contains planetary gear sets with hydraulically operated clutches and bands. But the operator has to manually select which gear/speed he wants.

64frd4000ind · Jan 29, 2015

Easy way to think of the SOS is Shift on the Fly with a shifter that is mounted on the steering column.

Larry NCKS · Jan 30, 2015

SOS is a power shift. It's the first full powershift ever put in a farm tractor. In other words it shifts without the use of clutch such as a gear transmission uses. But the operator selects the speed ratio it operates in. It stays in that ratio until he/she selects a different one. It has 10 forward and 2 reverse ratios. IMHO you can't get a better transmission in a tractor of that era.

Larry NCKS · Jan 30, 2015

SOS is a power shift. It's the first full powershift ever put in a farm tractor. In other words it shifts without the use of clutch such as a gear transmission uses. But the operator selects the speed ratio it operates in. It stays in that ratio until he/she selects a different one. It has 10 forward and 2 reverse ratios. IMHO you can't get a better transmission in a tractor of that era.

Sean in PA · Jan 30, 2015

(quoted from post at 20:33:38 01/29/15) You won't find an 8x4 in a 3000 or 3400. 8x2, 6x4, 4x4, 6x2, 4x1 would be the manual transmission options.

There were 2 different 4x4 transmissions for the '65-'75 3 cylinder tractors. One was the Torque Converter auto reverser, and the other was the earlier version of the manual reverser, which they only made for the first couple of years and then changed the manual reverser to the 6x4 on 4/1/68.

gears · Jan 30, 2015

Is it easy to swap transmissions? I figure if the SOS doesn't work right it might be cheaper/easier to put the 8/2 in. I suppose the steering column SOS shifter would need removed but overall things should interchange right?

Also, is there a reason an SOS would have a pto that doesn't work? (2 stage clutch with 1 stage bad for example)

64frd4000ind · Jan 30, 2015

Someone else posted on here that the rear differential ratios are different for SOS and 4/5 Speed.

If I remember right the SOS is something like 6.48 and the 4/5 Speeds are 3.08

You would need to dig more to find out for sure, but I think you would have to match those to the transmission you have.

Sean in PA · Jan 30, 2015

As 64frd4000ind said, the differential has a different ratio on the S-O-S tractors, which would make any other transmission half-fast with a S-O-S rear axle. Plus there would be a bit of parts swapping between the rear ends to get the PTO working too as I don't think the PTO shafts are the same length.

Better to swap the entire rear end from the trans back. Or, depending on the condition of the front axles, just swap the engine.

RickB · Jan 30, 2015

So your point is??? There was no 8x4 offering at that time. Did I need to be corrected on that? Not many 3000's or 3400's running around with a Power Reversing transmission.

gears · Jan 30, 2015

Yeah Sean, that's what I'd meant, swapping rear halves - that would only present an issue with the steering box...

In typing this I guess the motor swap would be the most straight forward. Or just run the whole SOS tractor and use this one for parts (like the ag tires).

Sean in PA · Jan 31, 2015

(quoted from post at 18:22:59 01/30/15) So your point is??? There was no 8x4 offering at that time. Did I need to be corrected on that? Not many 3000's or 3400's running around with a Power Reversing transmission.

Just trying to keep accurate information here for the archives as folks will come here and search on old posts years from now and they might have one of the 3400 models that did have a 4x4 auto reverser, that's all. They're might not be many, but they are out there.

select-o-speed or 8 x4H/L?

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