# 1974 Ford 4000 Blowing rear PTO seal Again



## drkstr (Sep 11, 2015)

I replaced the rear seal on my 1974 Ford 4000 Independent PTO tractor last year because while running the Brush hog with it the seal blew out. 
When i took it apart down to the bearing assembly (not removing the shaft) it looked fairly straight forward and i replaced the seal o rings and clips. Figured id be good for a long time. i saw no damage on the parts that show that looks like bearings around the PTO shaft and refilled with new fluid. This year low and behold i ran the brush hog again and Bam the seal blew out again. I'm not sure what i'm doing wrong here. both times the hubby was driving it when the seal blew out. The only way i have to test the amount of fluid in the rearend is to stick a ruler down there as someone else suggested to touch the top of the parts in there and see if it comes out with fluid on it. I ran the brush hog successfully for many years on this pto without incident. Now its blowing it out every time we have used it for two years. when replacing the seal i always assemble the cupped side in, replace all o rings and lubricate the heck out of them, and then put in the clips. Not sure whats going on if anyone has advice I'd surely appreciate it.
To add insult to injury. As I tried to get the brush hog off today I find that the entire shaft will come with it. Oh joy. So now I have a real problem on my hands. Do I have to split the case to fix this now?
Thanks :dazed:


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## EdF (Sep 15, 2014)

Hello drkstr,

Welcome to the tractor forum.

You may have a plugged breather on the rear differential section. See item #26 on attached diagram. Your tractor has a lift cover, but will have a breather somewhere. With a plugged breather, pressure builds up inside the rear end and can blow the PTO seal.

See item #9 on the attached diagram. Square headed pipe plug for checking fluid level in the rear end. Do not remove the slotted head screw near this pipe plug (or you'll be sorry!).

Check the PTO shaft for axial play (in/out) and any other bearing slop. Maybe too much PTO shaft movement is damaging the seal. 

Also check the PTO shaft to your bush hog. It may be frozen or very stiff due to a lack of grease on the slip joint. A frozen slip joint can put immense pressure on the tractor's PTO shaft.


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## EdF (Sep 15, 2014)

You have to pull the PTO shaft to replace the PTO seal. You probably need to take the shaft to a tractor repair shop or dealership to get it reassembled correctly. 

With an independent PTO, there is a washer/shim in the hydraulic clutch assembly that can (and probably will) drop down when you pull the PTO shaft, preventing the shaft from being reinstalled. If you shine a light in there you should be able to see it.

To overcome this obstacle, goober some heavy grease on a broomstick handle and work it thru the washer till the grease holds it in place. Don't give up on this approach, as the alternative is to split the tractor.


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## drkstr (Sep 11, 2015)

Thank you all for the posts. After diddling with the broom handle and grease for a long time it did slide all the way in. It seems engaged in there as it is in up to what i believe the hilt. I am attaching some photos because although the PTO shaft is not bent in any way or visibly damaged it seems that it is at a slight angle and not center of the insertion point. is this normal? Should i continue to put it all back together? Will the seals hold it in place and the outer housing? Questions questions questions. Thanks Again All

Please see attached photos.


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## Fedup (Feb 25, 2014)

I believe you're missing something here. There should be a snap ring in each of the grooves in the shaft,one on each side of the bearing in the picture. The shaft, the bearing, (snap rings installed) all go in as a package. Then there should be another internal snap ring holding the the bearing into the housing. That's what the parts breakdown shows. Then the seal retainer is bolted on over all that. If the photos show all the parts you have, it's no wonder you're having problems.


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## EdF (Sep 15, 2014)

When you pulled the PTO shaft, the bearing was supposed to come with it. WHY?? Because there is supposed to be two snap rings latched into the shaft.... one on each side of the bearing. That's to prevent the shaft from working in and out thru the bearing. 

So pull the bearing out and mount it on the shaft between snap rings. 

I don't know about the misalignment you are showing.....but I would guess it has to do with the clutch pack....Put it back together and keep an eye and ear on it during operation.

With two snap rings missing, it appears that something is pushing and pulling radically on the PTO shaft. Grease the slip joint on the bush hog PTO shaft. Make sure it is moving freely.

Is that bearing broken (the ball retainers)??

Ooops! Sorry Fedup, we were posting at the same time.


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## drkstr (Sep 11, 2015)

Awesome. We jacked with it all day and seriously kept thinking that it needed to come out and have a snap ring on each side of it. That's how it looked but this assembly has never come out. It is not broken just covered in grease, and i think we will replace it anyway, better safe then sorry. just ordered the new parts. There was actually only ever one snap ring and we fished it out of the inside of the housing today with a magnet once we drained the fluid. We took the side cover off looking to see if the shift fork or shift coller were moved and that was what was causing it ( the miss alignment) but that seems fine. Cotter key is in place and as far as we can tell it looks sound. When looking inside of the shaft hole from the back it looks straight and nothing seems to be amiss as far as we can tell although it is all covered in that black grease ( all i had to put the broom stick in there with). I agree get the snap rings and replace the bearings/ housing and put it back together, new oil seal and hope it works ok. He does not want to put it back together says we need to figure our whats wrong why it is off center, afraid it will cause damage in there. i say if it is spinning which it was when we removed it then its good enough for now. we don't need the PTO for the winter anyway but we do use the front loader and rear blade for plowing snow, and can't live without that and that time is almost upon us. All that stuff should still work fine, correct? i know they are not really connected. and i will check to see if there is a plugged breather. I never thought of that. I know that the shaft on the brush hog is tight as bark, ill work on that as well. All this poor stuff sits outside all the time, and we expect so much from it. This has been such a great tractor, and aside from some rigging it here and there myself because of some minor issues it has worked perfectly. I'm definitely NOT a tractor mechanic. But ill do whatever i got to to keep the old gal running heck i'm older then her and i'm still running sorta ! LOL Thanks all. Will update. if anyone else knows why the shaft would be hanging to one side when engaged in there let me know!


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## Fredneck (May 25, 2012)

i would be very nervous about running it like that. the bearing is essentially not in use like that, and the shaft itself, because of the ability to see both snap ring grooves in the pictures, is clearly not as far in as it should be. i'd want that shaft, with the bearing properly attached, inserted fully before i spun it again.


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## drkstr (Sep 11, 2015)

Im not sure what else to do to get it further in. I don't see any obstruction to it going further in. the broom handle does go all the way in, measuring it it does go all the way to where the shaft should go but we don't see why it wont go that far. Anyone have any other ideas? We have tried both with the clutch engaged and not engaged thinking it might help (no difference). I'm at a loss. I agree unless i can get it further in then it cant be put back together.


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## HarveyW (Sep 15, 2014)

After you get the snap rings and bearing in place on the PTO shaft, make sure the washer is goobered in place with grease, push the shaft through as far as you can. Try cranking the engine (makes certain it won't start, kill rod out on diesel, coil wire off on a gasser) to align things internally while you push on the shaft. You might get lucky.

If you can't get the PTO shaft in place, it looks like you will have to split the tractor between the tranny and rear end.


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## country Gent (Jul 22, 2010)

I would agree with EdF and Harvey on the clutch pack. The disc probably fell "off center" when you were taking it apart or when the pto shaft traveled back when it was running. That might be the reason you can't get the shaft all the way in. Not really a Ford person, just using some logic.?????? Get the broom handle out again an see if you can center it.


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## drkstr (Sep 11, 2015)

I Did it!!!! I was so frustrated and not wanting to split the case. Afraid to split the case, and no place or tools to really have a clue how to split the case, knowing it was last resort, and knowing that if i had to go that far it wouldn't really matter what i had done to it with the broom handle. So i threw the broom handle aside and got a fine steel cheater bar and greased that up and diddled that around in there. also put a block on the clutch peddle and worked the pto engage handle back and forth and kept going at it till VOILA!!! It gave. I then greased the readied ( new bearing and clips ) pto shaft up and she slid in and with a couple taps of a trusty BFH it slid all the way home. I am so relieved. I would like to thank you all for your help and suggestions and i am so glad i didn't have to split the case. Now before i run that dreaded brush hog ever again ( Next year) i guess it will need some work to make sure it is not binding the pto up. I am so relieved, and she holds fluid and turns on and off so i think it is all well. Thanks again. Whew!!! Ready for snow!


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## sixbales (May 18, 2011)

Outstanding report! The secret is to never give up when the going gets rough. Don't forget to clean and grease the slip joint on your bush hog PTO shaft. Congratulations! 

You got 'er done.


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## drkstr (Sep 11, 2015)

Thanks sixbales. Feels great. And stressing over snow coming is all gone. Get er done!


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