871 SOS Loss of Power Engine Dies

tom moore

New User
My 1959 871 SOS loses power when in gear and the engine dies. Sometimes this happens when I use the front end loader and most of the time it happens when I put it in R1 (low reverse) and in R2, and in gears 1-3.

It get's better sometimes when I am able to run the tractor through the gears and work it in and let it warm up to operating temp. When I give it full throttle the same thing happens too...regardless of throttle level.

Is this a carb adjustment issue? and I need to adjust the carb under load? or is it water in the hydraulic transmission fluid or low level tranny fluid?
 
First thing I would do is get a service manual if you don't already have one and then follow the procedures in the manual for checking the pressure and adjusting the bands. If it still has problems after that then proceed with other troubleshooting.
 
Not if you have the proper service manual.

Do not attempt to do so if you do not.

Dean
 
Check the easy things first.

When I first got my 64 4000 SOS it would run fine(I thought) until I turned on the PTO under load, then it would die.

Mine ended up being a kinked fuel line from the tank to carb. And a badly adjusted carb. to compensate for the slow fuel.

1. Check your fluid level in the SOS. Level plug is on the front right side of the SOS. Just a pipe plug into the side, full should be even with the bottom of the plug.

2. Unhook your fuel line from the sediment bowl, open fuel valve, make sure you have a good flow.

3. Check the screen in the sediment bowl, if its metal, take it out and burn it off to get rid of any lacquer that has built up on it. Or maybe even replace it with a new one.

4. Hook all that back up and remove the bottom plug on the carb and make sure you have a good flow there. If not pull the carb and clean the crap out of it, literally, wire through every passage, soak in cleaner and use an air hose with small nozzle to make sure its all clear. There is a carb adjustment procedure in the FO-20.

5. Get an FO-20 Manual, you can usually find them on the rack at the farm supply store for around $20, grab it when you get your carb kit and/or sediment bowl screen.
There is a section in the back that describes the band adjustments. [b:6a203014ed]DON"T FORGET TO DISENGAGE THE REAR END BEFORE YOU TRY TO MAKE ANY ADJUSTMENTS.[/b:6a203014ed] We don't want to hear how the tractor ran you over....
You can also pick up a pressure gauge when you do this, the manual will show you where to check the pressures during the adjustment.

You can do all those checks with a minimal cost. And without tearing into anything major.

6. If that all fails, you can follow the procedure in the FO-20 for removing the top cover to the SOS and checking the valve body for any stuck valves. If you get this far, go on the Dennis-Carpenter site and order a new filter for the SOS, they cost about the same as the manual did. Its a pain to remove the cover, so might as well do that while you are in there.

7. You will have to get a long flexible necked funnel to do this one, but you may drain the fluid from the SOS, the drain tube is on the lower left side of the SOS, you remove the retaining clip, and then pull out the filter tube and the fluid will drain. This tube also has a fine screen that functions as a secondary filter. Replace fluid with 134D equivalent UTF.

If all of that fails, then there might be fluid buildup or rust on the Direct Drive Clutch, or something else wrong with the SOS, but that is beyond my knowledge, and best to talk to the guys on here that do the work on them.

Do the easy/cheap checks first, heck it might end up being something as simple as the timing is a bit slow.

[b:6a203014ed]DO NOT OPEN THE TOP COVER OF THE SOS WITHOUT READING THE MANUAL.[/b:6a203014ed] You will spend forever getting it back right if you do.

[b:6a203014ed]IF YOU HAVE ANY QUESTIONS AT ALL DON"T BE AFRAID TO ASK!!![/b:6a203014ed] Its better to ask a simple question than spend time/money fixing something later....
 

Oil requirements for the SOS are night and day different from the standard transmissions. Let a little out the drain to see what it is like. just sitting around it can get very nasty. if it looks at all bad you could get significant improvement with just an oil change. Use UTF universal transmission fluid.
 
A Google search on "Valvoline 813" returns a Valvoline web page with specs that says this:

A multi-purpose all-weather tractor hydraulic fluid. Recommended for use in the following tractor systems:

hydraulic
final drive
transmission
differential
wet brake

And on the product spec sheet it says that it meets or exceeds the following:

New Holland Group(Ford New Holland) – FNHA-2-C-201.
00(134D), FNHA-2-C-200.00(Hydraulic Oil 134)

Ford New Holland ESN-M2C134-C, ESN-M2C134B, ESN-M2C134A, ESN-M2C86B, ESN-M2C53A, ESN-M2C48-B&C;

So yes, it is a UTF that meets or exceeds the M2C134D specification which is what you want in an S-O-S transmission.
 
thanks for the help to you and everyone else. I agree to start with the simple things too. I know my carb has issues - the choke is not adjusted and I am beginning to think the carb is one of the issues. My approach is to get the engine up to standard, do a basic tune-up with new plugs and oil too, clean and adjust the carb; make sure the motor is running in time and smooth.

Change the old tranny fluid.

And then give the tractor a run through.

Question: Power steering fluid for the power steering pump? What type and brand is recommended?
 

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