Ford 4000 with SOS, PTO will not engage

RNation

Member
I am new to this forum and pretty new to tractors so I just wanted to start with that :D

Recently I purchased a Ford 4000 SOS from my grandpa. The other day I was brush hogging and a hydrolic line ( located under the right side foot plate) came un-done. I noticed it fairly quickly and shut the tractor off right away, although a lot of fluid poured out.

After getting the line back in it's place and filling up the hydrolic fluids I was back to normal. About 30 minutes later I accidently buried the brush hog into the ground and the PTO quit working. Right now it will not engage at all. And (might be a separate issue) the 3 point hitch goes down fine but is jerky on the up motion.

My main concern is the PTO.

One thing I noticed was that when the tractor was off I could never turn the spline by hand, but now I can turn the spline by hand pretty easily.

The Ford dealership said they don't know what's wrong with it but it could cost $2700 and up, they wouldn't know until they dove in. I am on a budget however and cannot really afford an "open ended" estimate.

Any thoughts? Thanks in advance.
 
The SOS transmissions are above my pay grade so I can't help you.
But those folks who can help need to know if you have a 1962-65 4 cylinder 4000 or a 1965-75 3 cylinder 4000.
Based on your comment about the hydraulic line I suspect it is a 3 cylinder model but your description there could pertain to either one.
Welcome to the Ford board.
 
I agree with Ultradog that it sounds like a 3 cylinder 4000.

PTO and hydraulics sound like separate issues.

For the hydraulics, it sounds like the suction line was what got knocked loose, and now it's still not sealed fully so it's sucking some air along with the fluid.

For the PTO, it could be a few different things. The PTO clutch could have broken or the PTO output shaft could have sheared. If it has the "deluxe" dual speed PTO, or dual speed with ground speed, have you checked to make sure that it didn't just jump into neutral on the speed select lever down on the left side of the transmission?
 

I couldn't figure out how to reply to the thread without replying to a specific comment.

I have the 3 cylinder model. If there is dual speed I am not aware of that.

There are 2 levers on the right hand side that I noticed. 1 appears to go to the hydrolic hoses that have an air compressor style hook-up at the end (I don't use those). The other appears to be relevant to the hydrolics but I don't notice a difference in anything when I play with that lever.
 

Yep! We need to know which 4000 you have. but unless it's aftermarket, the early 4000 did not have hydraulic lines under the running boards on either side.

Regardless, your PTO should never have been impossible to turn on either one with the engine shut off. The PTO drive mechanism on all SOS tractors, except the 5000 is internal to the transmission and has no PTO brake.

I'm not that familiar with the later 4000s, but off the top of my head in a wild guess, it sounds as if the coupler sleeve at the rear of the transmission may have shattered. I'd look there first. The early 4000s had an inspection cover on the left side of the center housing. I've got no clue whether the later 4000s do or if they've got one at all. At any rate that would be the first place I'd look if this is a single speed 540 PTO.

If it does happen to be the deluxe 2 speed PTO, I'd check the shifters as Sean suggested.
 

took too long getting that reply written and posted (wish they'd fix the edit feature) Since you have identified your tractor as a later 4000, without 2 speed PTO (any controls for that would be on the left side of the transmission case) ignore anything I said about that PTO system.
 

To check the coupler sleeve if there is not an inspection cover, does that mean I'd have to split the tractor?

If it would help, I can get some specs for the tractor this coming weekend.
 
There is a round inspection cover on the
left (port) side of the rear center housing.
You will need to remove the step plate on
that side to open it. Just to be sure, the
lever that Sean speaks of is on that same
side.
 

Just to verify, is it the left side as I'm sitting in the seat or if I'm at the front of the tractor looking to the back?
 

In my mind the left side of the tractor is always the left side no matter which way you're facing. To answer your question it would be your left as you sit in the seat and face the same direction the tractor is facing.
 
I am not able to upload the pictures from my phone for some reason but I have the inspection plate off now.

While looking inside I see where the PTO shaft fits into a slightly bigger shaft.

When I spin the shaft from the back of the tractor, the smaller shaft spins also but the bigger shaft does not.

I do not see any visible signs of damage to anything.

What do you guys think?
 
Forgot to mention that it seems to be a one speed PTO. I do not see any of the levers on my tractor that are in the repair manual and regular manual on the left hand side.
 

I think you've found your problem! Pull the PTO shaft and determine whether it's the coupler or one of the shafts. If the coupler doesn't spin, it's either the coupler, as I had previously guessed, or it's the PTO shaft itself . . . or both!
 
Dang I wish I would have saw your reply
earlier.

Did the pto shaft come out of the back?
There doesn't seem to be an obvious way to
take it out.
 

drain fluid below opening, or face tractor down a steep, steep slope . . . four bolts and yank it out.

So, I'm curious. Why do you wish you seen my post earlier?
 
Because Im short on time haha.

This forum system is different then what
I'm used to (at least on my phone). I kept
refreshing the page after my last comment
but didn't see any new comments at the
bottom of the thread. When I layer down to
bed I decided to read through the comments
again and found yours.

So the shaft just pulls out?
 
After further examination the coupler and
shafts appear fine.

Is it possible the coupler could have slid
off of one of the shafts? I ask because I'm
noticing the back shaft doesn't seem to be
long enough to trash the coupler. And of
course I forgot to take pictures before the
shaft was removed.
 

Sorry I'm not familiar with that coupler's dynamics. My experience has all been on prior 4000s (the 4 cylinder ones). And it's been long enough since I've had a transmission/rear end split on one of them, that I'm not sure what keeps that coupler in place.

I do know however, That something has to keep that coupler from moving fore and aft on that shaft. If it's moved forward enough that it does not engage the PTO shaft, I'm going to suggest two things. 1. The ridge, dimples, snap ring or pin that keeps that coupler in position has failed. 2. Hitting the ground caused your mower PTO shaft to ram the tractor PTO shaft forward enough in its rear bearing to screw the coupler up. If the latter is the case, I'd think you'd be leaking oil profusely at PTO shaft seal on the rear of the tractor.
 
Well it's put back together and the pto
spins now while the tractor is on but the
pto cable is pulled to engage nothing
happens.

It does seem like the coupler had slipped
off somehow.
 
Correction, it is working. I had to hook it
up to my brush hog so that I could hear it
engage.

Is it possible that the coupler has no type
of mechanism to hold it in place on the
shafts?

Anyhow, thank you very much for the help.
If your ever in mid missouri let me know, I
owe you dinner!
 

thanks! Somehow the coupler has to stay put or it will work itself off again.

Where's mid-Missouri? I think my email is open on the modern view of this forum.

I'm planning to drive through on I-70 in late June!
 
I actually live right off of I70 in the
suburbs of st Louis so it's actually more
middle/east Missouri. My property where the
tractor is at is located more in the
middle.

I'll send you an email later so that you
can save it for when your passing through.
 

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