Dieseltech

Well-known Member
Location
Akron, Indiana
Have a question about my 871 diesel SOS, and the early 4000 SOS row crop gas I have also. Is the ring and pinion gear set the same in both tractors, and just flipped over for the row crop with the drop box axles? What is the gear ratio? Thanks.
 
They use a different ring and pinion. The rowcrops would be very slow (or the utilities would be very fast) if they used the same ratio.
I don't know firsthand, but I've been told there isn't room in the differential case to flip the differential.
 
(quoted from post at 13:25:41 02/11/19) Have a question about my 871 diesel SOS, and the early 4000 SOS row crop gas I have also. Is the ring and pinion gear set the same in both tractors, and just flipped over for the row crop with the drop box axles? What is the gear ratio? Thanks.
re you considering the final bull gear reduction at the wheel end of axles?
 
Now I'm more confused, 871, 971, early 4000 standard and row crops on the Messicks site shows they all could use C7NN4209C, 23 spline or C7NN4209D 10 spline inputs being the only difference. That's why I'm curious about the actual tooth count/ratios. What's the drop box ratio, if not one to one? Been looking at the 6000, it has 6.66-1, and either 4.93-1 or 4.5-1 axle planetary. Also curious if all SOS transmissions have the same speeds, 1 thru 10, or is the 6000 different?
 
Don't know the row crop final drive ratios but it is definitely not 1:1.

This is why Ford was able to use the 6** sized rear axle assembly rather than the 8** sized unit in the 9**/early 4000 tractors....

Dean
 
(quoted from post at 17:57:22 02/11/19) Don't know the row crop final drive ratios but it is definitely not 1:1.

This is why Ford was able to use the 6** sized rear axle assembly rather than the 8** sized unit in the 9**/early 4000 tractors....

Dean
url]https://forums.yesterdaystractors.com/viewtopic.php?t=1381129[/url]
 
Thanks! Another question, what is the tooth count on both ring and pinion on the 871? If the 900 and early 4000 row crop are 6 X 43, and drop box is 15 X 32, and what I've found on the 6000 is 6.66-1, 10 X 40 with axle planetary drop again of either 4.93-1 or 4.50-1. Is there that much difference in the SOS output speeds between the 6000 and early SOS models? Reason I'm curious is the book I have on tractor ground speed in each gear they are all very close with similar engine input speeds. The 6000 is a bit faster but has a large speed drop at the axle planetary, which makes me wonder about the SOS itself. Guess I could pull the 871 lift cover for the tooth count.
 
(quoted from post at 21:47:39 02/11/19) Thanks! Another question, what is the tooth count on both ring and pinion on the 871? If the 900 and early 4000 row crop are 6 X 43, and drop box is 15 X 32, and what I've found on the 6000 is 6.66-1, 10 X 40 with axle planetary drop again of either 4.93-1 or 4.50-1. Is there that much difference in the SOS output speeds between the 6000 and early SOS models? Reason I'm curious is the book I have on tractor ground speed in each gear they are all very close with similar engine input speeds. The 6000 is a bit faster but has a large speed drop at the axle planetary, which makes me wonder about the SOS itself. Guess I could pull the 871 lift cover for the tooth count.
s there a real problem to solve here? Or is this just idle curiosity?
 
The 6000 uses jubilee, 600, 601, and 2000 size parts in the differential. The part number for the differential carrier in the 6000 is NCA4204B, NAA4236A axle gear, C0NN4292A spider gear. 6000 used direct drive out of transmission to pinion in the rear axle. 601, 801, 901 used a planetary gear on the SOS output shaft to make output shaft speed equal the 4 speed and 5 speed output shaft speed. With the increase speed of the 6000 SOS output shaft they were able to use the lighter duty 601 differential parts.
 
Thank You! Now it makes sense why the 6000 has the 4.5-1 axle reduction. Next odd ball question, any chance the 6000 SOS would bolt up easily to a 971 row crop rear end? Am thinking of making a longer wheelbase power shift tractor with slightly higher speeds for tractor drive use only. Wheel base change would be turning both drop boxes 90 degrees, and making the whole tractor slightly lower also.
 
(quoted from post at 05:47:23 02/12/19) Thank You! Now it makes sense why the 6000 has the 4.5-1 axle reduction. Next odd ball question, any chance the 6000 SOS would bolt up easily to a 971 row crop rear end? Am thinking of making a longer wheelbase power shift tractor with slightly higher speeds for tractor drive use only. Wheel base change would be turning both drop boxes 90 degrees, and making the whole tractor slightly lower also.


Sounds like a interesting project! the diesel engine used in the 6000 would be the engine to use. We used to have a 6000, the engine had good power, and ran so smooth!
 
Yes, the 6000 and 901 trans to rear axle housings will bolt together. If you want to speed the 901 up for road use, all you need to do is remove the rear cover from the 901 SOS and replace it with a rear cover from a 6000 which does not have the gear reduction planetary. this will increase your road speed considerably. You may have to alter the coupling between the transmission output shaft and the pinion shaft, I dont remember how the lengths compare.
I have a chain drive skid steer made from a 4000 engine and 4-speed transmission and it is connected to a 6000 rear axle center housing, so I know that combination will connect together.
If you want more opinions, just ask.
Jim
 
Sounds like a Balmar loader.
mvphoto31316.jpg
 
I could get pics of my skid steer but it is like the Balmar loader ptfarmer pictured on this discussion. And I do have the disease. I put my first 6000 diesel in a Mercury Cougar in 1972, drove it 200,000 miles including 2 trips up Pikes Peak, once to California and several of the western states. I was stopped in California for exhaust smoke and the state patrolman let me go without a ticket after he looked under the hood. I put 6000 engines in a couple of different trucks, an 801 diesel in an early model LUV, 4BT Cummins in a little Ranger, a Ford Explorer, and a couple of Dakotas. The best fuel mileage was with the Cougar at 42.9 mpg. Next was the Ford Ranger at 39+.
Yea, I've got the tinkering disease. My current project is installing fuel injection on a '63 4000 gas powered SOS tractor.
Jim from Alabama.
 

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