Need SOS Help already

[PhilC]

Can't believe I'm already asking for help, but I don't know what else to try. '59 871 and here's the scenario - drove the tractor around the place a bit and then decided to knock down some small mounds of dirt and rock using the FEL. When I say small, I mean maybe a foot or so high and 3' - 5' diameter. As I was leveling the last one and released the inching pedal after changing from R1 to first, absolutely nothing happened. I thought I selected neutral instead, but double checked and it was in first. I tried shifting to other gear positions and had the same result - no movement in [b:bcd3618b92][i:bcd3618b92]any[/i:bcd3618b92][/b:bcd3618b92] gear.

I checked the trans fluid level and it's at the correct level, but I haven't changed the fluid since I got the tractor a week ago. Until today, the tractor has run just fine in all gears.

I have the factory shop manual, parts manual, and an I&T manual that covers the SOS. I don't have a pressure guage yet, so I can't tell what pressures are. I did check the traction disconnect, and it is set correctly (has to be, it worked until now).

I am hoping I've overlooked something simple, but I fear the worst. Appreciate any helpful advice other than swap it for a gear tranny. :wink:

 

[Larry NCKS]

Check and see if the PTO works. I'm betting no. Do you hear any of the transmission noises you might be used to by now? Again, I'm betting no.

The best guess from the keyboard is that your torque limiting clutch failed. This mandates a split between the engine and transmission. Since you have a loader on, it's a bit more involved. The loader will have to come off. Then you'll need to find repairs, which if available from New Holland, are costly. I have a used torque clutch disc I'd sell for half or less of the NH one. My email is available.

Let us know what you find when you've answered my questions in paragraph one.

 

[Anonymous-0]

Is the traction coupler still engage?
I purchased a tractor from a fellow who had taken the strap off of the traction coupler and it came disenaged. Just a thought.

 

[Larry NCKS]

If PTO is gone, it's not TC.

 

[Anonymous-0]

I.m betting torgue limiting clutch also. Sounds like a typical failure.
Dan Robertson

 

[PhilC]

Larry I just checked the PTO and it still turns, as a matter of fact I cannot stop it. I hadn't pulled the cover off until tonight and about a half cup of milky lube was in the cover. I know the hydraulic fluid has been changed and it is clean, so there must have been some seepage into the cover from the hydraulic reservoir as well as some condensation.

As for transmission noises, that's a tough one since I've only had the tractor a week and have never owned one before. Yes, there are some noises coming from the tranny when I shift through the different ranges, and the engine lugs a bit in both R1, R2, and 10. Since I have a none functioning proofmeter I cannot tell you by how much. Selecting 10 pulls the engine down pretty good. I did not let off the inching pedal all the way in 10. I do have a remote inductive tach I could connect to find out, but don't know if it has a 4cyl setting. It would be, what, half the 8cyl reading, right?

As far as I can tell the traction coupler is engaged, at least without removing the side cover, and the strap is still there. Earlier I did remove the strap and set the coupler rod as far as it would go and tried to move the tractor. No change. Just how much movement should there be with the lever? Half a turn? Quarter? I can post pics of the positions if necessary.

Thanks for the suggestions so far, where do I go from here?

 

[john_Bud]

Let's go over the issue step by step.

1) If the Torque limiting clutch snapped on you, there would be no coupling to the engine. The PTO would not work. Your's works, so cross off one failure mode.

2) Traction coupler disconnected would fit your symptoms. Can you move the tractor with the engine off? If you can roll it the TC is disconnected. or..

2b) The rear pinion could have snapped. Trans may be fine, but differential broken. You need to take off the access port and take a look in the hydraulic reservour to see what is going on.

3) Could the shift cable be broken? Trans is in N - no motion when you shift because it isn't shifting the transmission.

4) Trans is broke. Maybe a pressure line cracked from the pump or the suction line from the sump. Other "serious" breaks are unlikely as there are not many things that would snap and disable ALL gears.


I'm no SOS expert, just my $0.02. Spend them wisely...

jb

 

[Larry NCKS]

Phil, if I may, where are you located?

The fluid in your PTO cap (I'm amazed that it actually has one on there) is rear axle grease. It simply means the rear PTO seal is leaking. The fact that it's milky indicates water contamination. This could be from the rear axle itself or from water mixing with the leaked oil in the cap. I'm betting it is time to change the lube in the rear axle. As a matter of fact, if you haven't changed any of the fluids except the hydraulics on a new purchase, it's likely time to do it. The hydraulic reservoir is sandwiched between the transmission and rear axle. Thus there is no possibility of it getting to the PTO cap.

This brings up another question: Is the transmission oil level up to place and is it clean? The transmission is a separate reservoir. Its lube and drive pressure oil is all contained within itself.

I know nothing about inductive tachs.

The TC lever probably moves a quarter to a third turn. John's question about whether you can move the tractor with the engine off is valid. If you can do any more than slightly rock the tractor with the engine shut off, you've got a TC disconnect or other problem. I have known SOS mechanics to miss the slot in the coupler when replacing that side cover. After a little run the coupler just slips off the shaft. COULD THIS BE YOUR PROBLEM? If it is, you'll need to remove that side cover and get the lever and the coupler in sync. You may need to pry the coupler loose from it's disengaged position if this is your problem. If it became uncoupled under pressure it will likely lodge itself in the disengaged position tight enough to need more than the little lever to move it.

Since your PTO is working, we can likely rule out the torque limiting clutch (TLC). Although it may be possible for it to pull a no load PTO and yet be slipping enough not to drive the tractor.

We can also likely rule out your shift cable since you notice some variation of transmission/engine noise/RPM in certain gear ratios.

If all this fails, you'll need to get out the guages and check the hydraulic pressures at all 3 bands. There is a how to flow chart in the service manual for this.

Which brings up a final point: If you do not have both an operator's manual and a service manual for your tractor, you really should obtain originals (or a copies of) both Ford owner's and service manuals.

Let us know where you get from here.

 

[PhilC]

Great replies from you Larry and John_Bud. Let me try and answer what I can without having done much more since my last post last night.

I am located in Eastern WA, just south of Spokane. Larry, I know you are in north central KS, so we are a long way apart.

In reponse to John_Bud's questions:

[i:5c75a9831d]1) If the Torque limiting clutch snapped on you, there would be no coupling to the engine. The PTO would not work. Your's works, so cross off one failure mode.[/i:5c75a9831d]

[b:5c75a9831d]Agreed[/b:5c75a9831d]

[i:5c75a9831d]2) Traction coupler disconnected would fit your symptoms. Can you move the tractor with the engine off? If you can roll it the TC is disconnected.[/i:5c75a9831d]

[b:5c75a9831d]I'm thinking this may be the culprit somehow, despite its position being checked and double checked yesterday. I'll try and move the tractor today and will post results.[/b:5c75a9831d]

[i:5c75a9831d]2b) The rear pinion could have snapped. Trans may be fine, but differential broken. You need to take off the access port and take a look in the hydraulic reservour to see what is going on.[/i:5c75a9831d]

[b:5c75a9831d]I'm thinking this would have been a very noticeable event. I've done this in a car and there was no question something really big had just happened. On my tractor, I had backed up, depressed the inching pedal, shifted to neutral, then to first and let off the pedal slowly. I didn't even have the bucket on the ground at that point, so it was not under load. No bang, snap, or other noise just no forward movement.[/b:5c75a9831d]

[i:5c75a9831d]3) Could the shift cable be broken? Trans is in N - no motion when you shift because it isn't shifting the transmission.[/i:5c75a9831d]

[b:5c75a9831d]I don think so, I do get some RPM changes when selecting R1, R2, & 10, and I can hear other noises as I shift through the other ranges.[/b:5c75a9831d]

[i:5c75a9831d]4) Trans is broke. Maybe a pressure line cracked from the pump or the suction line from the sump. Other "serious" breaks are unlikely as there are not many things that would snap and disable ALL gears.[/i:5c75a9831d]

[b:5c75a9831d]Don't know yet. Have to try and move tractor ans see where that gets me.[/b:5c75a9831d]

Larry,

I assumed the fluid in the cap was a leaking PTO seal. I haven't checked the rear axle lube yet, and I didn't ask the guy I bought it from if he had changed it. I know for certain he changed the fluid in the hydraulic reservoir.

I also can't remember whether or not he changed the trans fluid. It is clean, not milky at all, and up to proper level. Matter of fact, it's overfull as my trans has a street "L" on it. I pulled the plug yesterday and fluid came out. The tractor is sitting on a slight grade leaning to the right.

I have an inductive tach/dwell meter, it simply clips over a plug wire like an inductive timing light. I'm pretty sure the reading is half of 8cyl, but it's been years since I played around with one.

If the TC lever moves a 1/4 to 1/3 turn in total, then I have the proper amount of movement. Yes, this could be the problem and I'm hoping it is. I can easily move the TC shaft with my fingers and it doesn't feel like anything is sliding back and forth on a shaft. I'll try and move the tractor first, then start by pulling the TC side cover and see what's going on in there.

On your final point, I've been reading the forums here for a couple months now, trying to get smart on this tractor and the SOS in particular. One of the first things I did after learning what model this tractor is was order a shop/parts/owners manual for the 801. My shop and parts manual cover the SOS, but my owner's manual does not. I'm hoping to get one very soon (have a bid on an original one on eBay right now).

I'm fairly good with automotive mechanicals, but things are a little different with the tractor. I know it's power flow issue, trying to diagnose it is a little bit of a challenge when you have no working knowledge of the thing.

A [i:5c75a9831d][b:5c75a9831d]big thanks[/b:5c75a9831d][/i:5c75a9831d] to you and John_Bud for all your insight and wisdom. I really appreciate both of you taking the time to help me pinpoint the problem.

 

[PhilC]

[b:56b927e98a]Great News![/b:56b927e98a] It was the traction coupling!!!! Apparently the lever was not put back in place correctly on the coupler. I manually slid the coupler back onto the differential input shaft (terminology?) and then placed the side cover back on. I could not get the lever to stay in the coupler ring groove and then noticed that a full 1/4" is worn away on the end of the lever where it's supposed to ride in the groove. It's sliding right over the groove.

I'll need to have the lever welded and turned down to make it work right, but at least the tractor is mobile, well, until the coupler slips off again.

[i:56b927e98a][b:56b927e98a]Thank you[/b:56b927e98a][/i:56b927e98a] for your help. I hope I never need to ask again, but I'm really grateful that you guys are here, and willing, to help others out. 8)

 

[Anonymous-0]

Great to hear that was the problem. On my 871, someone installed the tractor coupler on backwards which allowed it to slip off or out of the grove when you disengaged it. Enjoy your 871. They are a very good tractor.
Bill

 

[Larry NCKS]

Glad you got her figured out. God bless!