Ford 4000 PTO Wont Engage

[Dwilshire]

Hello all, I just bought a 1964 Ford 4000 with the 4 cyl gas engine and SOS trans. I am new to AG tractors but have worked on cars and heavy machinery. I cannot figure out why my PTO won't engage. The PTO free spins while running the tractor with and without the lever being pulled. Even if the lever is pulled I can stop the PTO shaft with my bare hands. I let go and it spins again. I found this out when I hooked up my bush hog and it wouldn't spin it at all. The bushhog works fine and isn't locked up. All 10 forward gears and 2 reverse gears work fine. No matter how high the tractor is revved the PTO wont move when hooked up to the bushhog. The rear (diff) fluid is at the proper level but does have some water in it (yes I am going to change it). Transmission has the elbow piece on the fill/check port and I could see some fluid at the bottom of the elbow. Pressure gauge shows right over 50 with or without PTO engaged. I have both manuals that everyone recommends in the other threads on the way but need this fixed soon. Any help is much appreciated

 

[Sean in PA]

First off, don't try to stop the PTO with your bare hands. If it won't stop you will be injured, possibly severely.

Also, which specific pressure test from the manual are you performing when you say that it reads 50 psi with or without the PTO engaged? I don't remember a PTO related pressure test, only one to test the overall pump pressure for the transmission, and that requires the traction disconnect to be disconnected and for the transmission to be in a certain gear, but I don't remember which gear off the top of my head. That same pump is used to power the hydraulics for the gear shifting as well as the engagement of the PTO clutch. 50 psi seems a bit low to me. I don't have any manuals nearby, but I seem to remember something more in the 160 to 210 psi range.

 

[Dwilshire]

I know I shouldn’t but the shaft is spinning at maybe 100-150 rpm. And the pressure I’m talking about is off a gauge that is on the cluster it has the transmission symbol on it but may just be a aftermarket gauge hooked to something else. I’m thinking tomorrow that I’ll drain the trans and rear and refill with new fluid because the lift arms are a little slow up and down but as I said the fluid in the rear doesn’t look great.

 

[Dwilshire]

I just noticed that my pto shaft has forward and rearward play. Seems I can push it in about a half inch or more (not sure if that matters, but doesn’t seem right). Free spins either way. Noticed a small leak at the hydraulic pump and at the pto shaft seal.

 

[Sean in PA]

And the pressure I’m talking about is off a gauge that is on the cluster it has the transmission symbol on it but may just be a aftermarket gauge hooked to something else.

Post some pictures of your instrument cluster. That tractor may have originally had a pressure warning light for the transmission, but that only required 5 to 10 psi to shut the light off, but they stopped including the warning light at some point, so I can''t say for sure whether yours would have had that. but they definitely did not come with a transmission pressure gauge.

I’m thinking tomorrow that I’ll drain the trans and rear and refill with new fluid because the lift arms are a little slow up and down but as I said the fluid in the rear doesn’t look great.

Changing the fluid in the trans and rear axle won't affect the 3 point hydraulics. There are three separate sumps on that tractor in addition to the engine crank case oil pan. From front to rear they are the transmission, the 3 point hydraulics sump and the rear axle.

 

[Dwilshire]

So I traced the gauge back and it is hooked to the engine. Definitely not a transmission pressure sensor. No warning light. All three sumps have water in the hydraulic oil so I’ll be able to put the 3 five gallon buckets of fluid I have to good use. I still haven’t pulled the shaft out but i’m hoping it’s something cheap and easy. The back and forth slop on the shaft just worries me.

 

[Sean in PA]

I believe that the PTO shaft goes from the rear of the tractor all of the way up to inside the transmission. It is an independent PTO that is driven off of a hydraulically controlled clutch pack that is inside the transmission. Make sure that you follow the procedures in the Service Manual when removing that shaft. I am not intimately familiar with that model, but there may be a thrust washer that can fall out of place when you remove the shaft and if that happens it might incur many extra hours of labor to get things back together correctly.

 

[Dwilshire]

I see in the standard supplement that there is a thrush washer on the 8 speed models but the sos manual does not show one. Just 4 bolts then pull the shaft. Install shows the same. Line up teeth and push in on pto shaft then four bolts. Guess I’ll find out within the next few days. Thanks for the help! I’ll video the process and if it’s useful I’ll throw it on youtube.

 

[shaun wallace]

Best to pull trans disconnect cover to make shure coupler stays on trans when removing pto shaft . It will not take all 3 buckets of oil to refill.

 

[Dwilshire]

Can anyone confirm how much fluid the three dumps should hold everywhere i’m reading including the manual says 6 gallons & 2-1/4 quarts in the rear axle and hydraulic lift system combined. I was only able to get a TOTAL of 6 gallons from all three sumps (transmission, center/hydraulic, and rear axle). Doesn’t seem right. PTO shaft was fine but does have play. All fluid was milky (see picture).

 

[Dwilshire]

Refilled with proper amounts of fluid and now the PTO doesn’t even free spin.