800 SOS

[Mike Fernandes]

Aloha Some months I asked for some information on this forum about this 800 SOS. I purchased this tractor today and had a chance to drive it today.Both reverses work, fowards 2,4,6,8,10 work fine there is no 1,3,5,7,9. Could there be a external adjustment that can be made to bring back the odd gears. I have a spare 5 speed that I could replace the SOS. Is the SOS rear gearing the same as the 5 speed. Need some help and recommendations.Mahalo Mike
 

[Larry NCKS]

I'd bet R1 doesn't work like you think it does.

Next let's determine what tractor and transmission you really have. I'm guessing you have an 801 series tractor, as the SOS was not avaialable in a *00 series tractor. If, indeed, you have an 801 series and it has the original ORC transmission , your sprag clutch is out.

I would never advocate switching to a 5 speed. Of course there are many that would. Furthermore, the output shaft on your 5 speed may be courser splined than the SOS, mandating the manufacturing of a coupler. If your 5 speed does not have the live PTO option, you'll lose that capability. If it does have it, you'll need the clutch assembly that goes with it, as well as the PTO actuator and related parts.
 

[Mike Fernandes]

Aloha Larry Mahalo for the quick response. You are correct it is a 801 SOS and R1 and R2 seem like they are going at the same speed.I have two spare transmissions a 5spd and a 4spd all small spline. I have all the flywheels ect and a couple of rear ends small spline. Is the 801 SOS rear end large spline or small spline. Getting the SOS repaired in Hawaii is impossible. I bought it for $1500.00 because it runs great and the sheet metal is in great condition, hardly any rust and all four tires are new.Is the gear ratio on the SOS rear the same as the standard rear end. Again mahalo for the response. Mahalo Mike
 

[Larry NCKS]

Mike, as I understand it, early 4 and 5 speeds had output shafts with course splines, whereas all SOS were fine splined. At mid *01 production all transmissions had the fine splined output. It is not a difference of size of the shaft, but the number of splines, 10 vs. 23. The serial break shows to be 106115 and start date 1/1/60.

If you have a 23 spline end on your 5 speed output shaft you've got a direct exchange. If you have 10, you'll have to manufacture a coupler.

There is no difference in rear end ratios. 5 speeds run more slowly on the road because 5th gear ratio is roughly akin to 9th gear on the SOS. 4 speed road speed is somewhere around halfway between 5 speed and SOS.
 

[Mike Fernandes]

Aloha Larry A big mahalo Larry for the information you sent me today. I have a clear understanding of what my options are. People like you make this forum the greatest. Mahalo Mike