kingslandkid
Member
I would just like to share my latest experience with the SOS transmission. I have owned several over the last 30 years and have grown to like them because of the wide range of gear choices over the old 4 and five speeds of which I still have one of each and a 62 4000 SOS diesel. I rebuilt one back in 1986 and forgot most of what I did to it but it worked in my backhoe until I sold it years later. From the folks around here in Indiana I am in the minority of people that like SOS's or "jerk-0-matics" as they call them. So when most of the owners ask me to fix a faulty SOS I either declined to work on it or talked them into swapping it for a 4 or five speed or a known good SOS from another tractor. I always kept the old transmission just in case I needed parts.
This summer a good customer of mine brought me his 1966 5000 with half the gears not working. I really didn't want to repair it so we looked for an 8 speed to swap out the SOS but all we could find were expensive conversions so I told him I would work on it over the winter when I was looking for something to do. Well I bought a few too many tractors this summer and my barn/shop is filled to capacity so I decided to tear into it now and if I found too much wrong or if I was in over my head I would step up my search for an 8 speed.
The first thing I did was get out my Ford 2000 - 7000 service manual and read, study and understand the 5000 - 7000 SOS section. I compared the charts in the manual with the operational diagnosis from the tractor and determined the no. 1 band was not holding. The manual stated I could get to the front no. 1 band by splitting the tractor at the transmission / rear center section and removing everything from the rear. I then made a support for the rear of the engine and transmission. I also have a machine shop which helps. I followed the manual word for word and step by step till I got to the no. 1 band which was burnt to a crisp just like I diagnosed. Having parted out a 4400 transmission, I salvaged the band with the help of the New Holland parts website and installed it in place of the defective one. I rebuilt the no. 1 servo and replaced every o-ring and gasket I removed with New Holland parts which CNH had in stock in the Indy warehouse. I followed the assembly procedures outlined in the service manual to the "t" being extremely careful with the cast iron slip rings. I even coated them and the bore with STP. The reassembly is really pretty straight forward. The sub-assemblies are heavy but manageable and it went together fairly easy. After re-bolting the rear end back on and setting the bands temporarily I put CNH Ambra oil in to the top of the fill plug. I double checked the traction decoupler before I fired it up. I made sure the SOS shifter was registering correctly and started shifting it through the ranges and all worked well so I shut it down and engaged the traction coupling and sat on the seat and restarted the engine and with the inching pedal down put the shifter in R1 and slowly let out the pedal and the old 5000 started to move backwards. I gave it a little throttle and backed it outside to warm up the transmission. After it warmed up I decoupled the the traction coupler again and set all three bands just like the service manual stated. With the engine off is when I torqued the no. 1 band to 20 ft/lbs which pretty much compresses servo spring to the end of its travel then back it off 1 1/4 turns and that's it. I recoupled the traction coupling and started it and ran it through all the gears and it worked fine. So I took it out on the road for a 3/4 throttle test and it worked fine so on the way back I ran it through the gears at full throttle and it shifted strong and fast just like it should.
The owner picked it up the next day and when I called him he was using it and said it was wonderful and now he is glad he didn't put in an 8 speed.
My reason for sharing this with you is that it wasn't as hard to work on a Select-O-Speed as I had remembered. In fact it in some ways is easier than the 5 or 8 speeds because all the carriers, sun and planetary gears are all in line and there are no side gears or shifter rails or detent balls to mess with. The most important thing is follow the manual and make sure every thrust washer is in place and do the clearance checks before you disassemble the whole transmission. I have been putting off replacing my 4000 4 cylinder diesel's PTO clutch, which is weak, but know I am looking forward to getting into it, but I think I have to tear that one down from both end to get to the PTO clutch.
This summer a good customer of mine brought me his 1966 5000 with half the gears not working. I really didn't want to repair it so we looked for an 8 speed to swap out the SOS but all we could find were expensive conversions so I told him I would work on it over the winter when I was looking for something to do. Well I bought a few too many tractors this summer and my barn/shop is filled to capacity so I decided to tear into it now and if I found too much wrong or if I was in over my head I would step up my search for an 8 speed.
The first thing I did was get out my Ford 2000 - 7000 service manual and read, study and understand the 5000 - 7000 SOS section. I compared the charts in the manual with the operational diagnosis from the tractor and determined the no. 1 band was not holding. The manual stated I could get to the front no. 1 band by splitting the tractor at the transmission / rear center section and removing everything from the rear. I then made a support for the rear of the engine and transmission. I also have a machine shop which helps. I followed the manual word for word and step by step till I got to the no. 1 band which was burnt to a crisp just like I diagnosed. Having parted out a 4400 transmission, I salvaged the band with the help of the New Holland parts website and installed it in place of the defective one. I rebuilt the no. 1 servo and replaced every o-ring and gasket I removed with New Holland parts which CNH had in stock in the Indy warehouse. I followed the assembly procedures outlined in the service manual to the "t" being extremely careful with the cast iron slip rings. I even coated them and the bore with STP. The reassembly is really pretty straight forward. The sub-assemblies are heavy but manageable and it went together fairly easy. After re-bolting the rear end back on and setting the bands temporarily I put CNH Ambra oil in to the top of the fill plug. I double checked the traction decoupler before I fired it up. I made sure the SOS shifter was registering correctly and started shifting it through the ranges and all worked well so I shut it down and engaged the traction coupling and sat on the seat and restarted the engine and with the inching pedal down put the shifter in R1 and slowly let out the pedal and the old 5000 started to move backwards. I gave it a little throttle and backed it outside to warm up the transmission. After it warmed up I decoupled the the traction coupler again and set all three bands just like the service manual stated. With the engine off is when I torqued the no. 1 band to 20 ft/lbs which pretty much compresses servo spring to the end of its travel then back it off 1 1/4 turns and that's it. I recoupled the traction coupling and started it and ran it through all the gears and it worked fine. So I took it out on the road for a 3/4 throttle test and it worked fine so on the way back I ran it through the gears at full throttle and it shifted strong and fast just like it should.
The owner picked it up the next day and when I called him he was using it and said it was wonderful and now he is glad he didn't put in an 8 speed.
My reason for sharing this with you is that it wasn't as hard to work on a Select-O-Speed as I had remembered. In fact it in some ways is easier than the 5 or 8 speeds because all the carriers, sun and planetary gears are all in line and there are no side gears or shifter rails or detent balls to mess with. The most important thing is follow the manual and make sure every thrust washer is in place and do the clearance checks before you disassemble the whole transmission. I have been putting off replacing my 4000 4 cylinder diesel's PTO clutch, which is weak, but know I am looking forward to getting into it, but I think I have to tear that one down from both end to get to the PTO clutch.
