1972 Ford 4000 Select-O-Speed Problems

skyrabian · Oct 4, 2014

I have a Ford 4000 farm tractor. It has a 3 cylinder diesel and a 10 speed select-o-matic transmission. Recently I have lost Reverse 2 and Forward gears 3,4,7,8 and 10. Reverse 1 and Forward gears 1,2,5,6 and 9 still work. Does anyone know what this symptom means and what it would take to repair? Is there any Ford service specialist out there? Thanks, Ken

Soundguy · Oct 4, 2014

did you check out the sos troubleshooting tips link?

CircleRat · Oct 5, 2014

I too have a SOS (Select-O-Speed) transmission on my '65 Ford 3000 gas burner. I haven't had it very long but I'm learning fast thanks to some expert help here on this forum including SoundGuy above and RickB. I've found having a Ford I&T shop manual (NO. FO-31) is invaluable, I recommend getting one if you haven't already. I found mine on eBay for around $25 shipped.

In the manual is a chart (page 81) that shows reverse 2 and forward gears 3,4,7,8 and 10 are all related to transmission Unit #1 (Servo #1 and Band #1). This would lead me to believe that Unit #1 may be out of adjustment in your case. Also in the manual a control valve adjustment is recommended in the step-by-step outline of the testing and adjustment procedures. To perform the procedures you need a hydraulic pressure gauge. I intend to purchase one myself ASAP.

If it hasn't already been done I would first check the fluid level and clean the lower pump filter screen. I'd also recommend replacing the main transmission filter (NH # 309735) and the fluid (AMBRA 134G), both available at the New Holland dealer, about $110 for all.

skyrabian · Oct 5, 2014

SouNdguy; I did try that link. It had a symptom similar to mine, but it was reversed. I wrote to smith8n on that site and he told me that it sounded like #1 band. I have not had a chance to check it out yet. Thanks for your input!!

CircleRat; I do have all the service manuals, but I thought that I would try just asking first. Sometimes those service manuals seem like they were written in some other language! Now that I have a direction, I will see if I can interpret the manual! Thanks for your input as well!!