8N PTO Seal

[Noelie84]

Good morning! Long time lurker, first time poster.

I recently picked up a new-to-me 1951 8N. Somebody's father had 'restored' it years ago, mostly by painting the chassis/frame with red paint (including all of the zerks ) and painting the sheet metal the wrong color gray, and then it sat in a pole barn when he died about 5 years ago. Fortunately the engine still has good compression, so after replacing the ignition pieces/parts, changing the oil, and rebuilding the carburetor it runs and drives like a top. However, the PTO shaft seal leaks semi-aggressively and needs to be replaced.
My question is about the seal itself; looking online there are two types of seals, one that has a metal casing/OD and one that has a rubber casing. Does anybody know what the OE seal would have been? Does it matter for this application? In my experience the metal-cased interference fit seals last longer but rubber-cased seals are better for high-vibration applications.

Thoughts or advice from the crowd? With the price of Tractor oil these days I don't want to have to do this twice

Photo of the patient for attention:

 

[R Geiger]

I do not know which seal is best but would be inclined to use the metal case one, how ever if you part the front wheel in a ditch, you will not lose all that much oil.

 

[Noelie84]

I do not know which seal is best but would be inclined to use the metal case one, how ever if you part the front wheel in a ditch, you will not lose all that much oil.

That's an idea, but the ditch in front of my house is about 8 feet deep, so I don't know if I'd be able to get the tractor back out after I replaced the seal!

 

[DanielW]

Does yours still have the original small (useless) PTO splines? If so, just replace the whole shaft, bearing, and seal assembly as one with a new shaft with the 1-3/8" splines. That way you don't have to use any goofy conversion sleeves or overrunning adapters to run any equipment. The new shaft kits come with the bearing, seal, and shaft already assembled as a unit, and they only cost about $90. Unbolt, slide old one out, slide new one in. As mentioned, if you park facing downhill, you don't lose much/any fluid. Doesn't have to be much of a slope: Parking with the rear wheels on some 6X6 blocks usually is enough. You might lose a little fluid, but hardly any.

If yours already has the 1-3/8" splines, then it probably makes sense to replace the seal alone. But because it's leaking, and knowing they generally last decades before they start to leak, I'm strongly suspecting that yours has the goofy/useless smaller splines, so it would be crazy not to convert it while you're at it.

https://www.yesterdaystractors.com/Ford-8N_PTO-Shaft-Conversion-Assembly_9N70038.html

 

[Noelie84]

Does yours still have the original small (useless) PTO splines? If so, just replace the whole shaft, bearing, and seal assembly as one with a new shaft with the 1-3/8" splines. That way you don't have to use any goofy conversion sleeves or overrunning adapters to run any equipment. The new shaft kits come with the bearing, seal, and shaft already assembled as a unit, and they only cost about $90. Unbolt, slide old one out, slide new one in. As mentioned, if you park facing downhill, you don't lose much/any fluid. Doesn't have to be much of a slope: Parking with the rear wheels on some 6X6 blocks usually is enough. You might lose a little fluid, but hardly any.

If yours already has the 1-3/8" splines, then it probably makes sense to replace the seal alone. But because it's leaking, and knowing they generally last decades before they start to leak, I'm strongly suspecting that yours has the goofy/useless smaller splines, so it would be crazy not to convert it while you're at it.

https://www.yesterdaystractors.com/Ford-8N_PTO-Shaft-Conversion-Assembly_9N70038.html

Hm...I'll have to check and see what I've got. It has an ORC on it right now so I wouldn't be surprised if it's the small shaft. On the other hand, the old owner used it with a rotary cutter so even if it was the newer/bigger shaft he would still have wanted an ORC to keep from feeding back through the PTO.

 

[DanielW]

There are lots of differing opinions on ORC's. Some folks will disagree with me, but I never saw why folks get so hot/bothered about them. Here was my note about them on another thread about pretty much the same subject not long ago:

"Even if you want an over-running clutch, I'd still swap shafts and get a standard 1-3/8" to 1-3/8" overrunning clutch. But frankly, I never understood why so many folks get so hot/bothered about having over-running clutches on N's. All N's (and most other makes/models through the 1950's) had geared PTO. And folks used (and most still use) them without overrunning clutches for everything - typically for much heavier and higher-inertia work than what most people are using an N for today. True, if you happen to be driving at top speed toward a brick wall with a bush hog and hit the clutch to stop when you're only 4' from the wall, the mower's rotary inertia will drive the tranny and keep you moving forward for a few feet and you might hit the wall. An overrunning clutch will prevent that. But another way of preventing that is to just not be driving towards a brick wall at top speed with a bush hog and only hit the clutch to stop when you're only 4' away. Drive and operate your implements with some common sense and there's no reason you need an overrunning clutch."

 

[Hobo,NC]

There is nuttin I can say bad about the modern neoprene seal. I prefer it over the metal clad style.

 

[Noelie84]

There are lots of differing opinions on ORC's. Some folks will disagree with me, but I never saw why folks get so hot/bothered about them. Here was my note about them on another thread about pretty much the same subject not long ago:

"Even if you want an over-running clutch, I'd still swap shafts and get a standard 1-3/8" to 1-3/8" overrunning clutch. But frankly, I never understood why so many folks get so hot/bothered about having over-running clutches on N's. All N's (and most other makes/models through the 1950's) had geared PTO. And folks used (and most still use) them without overrunning clutches for everything - typically for much heavier and higher-inertia work than what most people are using an N for today. True, if you happen to be driving at top speed toward a brick wall with a bush hog and hit the clutch to stop when you're only 4' from the wall, the mower's rotary inertia will drive the tranny and keep you moving forward for a few feet and you might hit the wall. An overrunning clutch will prevent that. But another way of preventing that is to just not be driving towards a brick wall at top speed with a bush hog and only hit the clutch to stop when you're only 4' away. Drive and operate your implements with some common sense and there's no reason you need an overrunning clutch."

I'm of a similar opinion; I've run older equipment before and never had an issue with it. I think it's similar to the exaggerated tendency of old tractors to flip over when they had implements hooked up to the 3pt; it happened to a few people who were using their equipment 'just wrong' and then the stories got taller with time.
If this hadn't come with one already installed, I probably wouldn't have bothered buying one. But, since there's already one on there, I'll probably leave it on when I use this to run my flail mower.

 

[DanielW]

I'm of a similar opinion; I've run older equipment before and never had an issue with it. I think it's similar to the exaggerated tendency of old tractors to flip over when they had implements hooked up to the 3pt; it happened to a few people who were using their equipment 'just wrong' and then the stories got taller with time.
If this hadn't come with one already installed, I probably wouldn't have bothered buying one. But, since there's already one on there, I'll probably leave it on when I use this to run my flail mower.

Fair enough. If it were mine, however, I'd still convert shafts to one with the larger splines. The ORC's on those older small splined shafts often get sloppy and wobbly - especially if the implement you're running has a large unsupported span of PTO shaft. And when you use one, the distance between the end of the PTO shaft and drawbar effectively changes, so you start having to cut down all your PTO shaft lengths to non-standard sizes, and then they often don't have enough overlap to work on any other tractors. I'd rather spend the $90 and have a whole new kit/caboodle that's correct and stronger right from the get-go.

 

[Noelie84]

Finally had some nice weather and some spare time line up today so I pulled the overrunning clutch off and found.... an 1-1/8 shaft. So, upgraded shaft and bearings it is! Thanks for the recommendation.

 

[Dober_paw]

Surprised I haven't seen anyone post about the downside (no pun intended) of parking head down in ditch - that oil will leak into clutch area and then you'll be into a splitting headache. (I'll see myself out).

 

[DanielW]

Surprised I haven't seen anyone post about the downside (no pun intended) of parking head down in ditch - that oil will leak into clutch area and then you'll be into a splitting headache. (I'll see myself out).

If your front tranny seal is that bad that oil will leak into the clutch when facing downhill, you've got much bigger problems on your hands, and it'll need to be fixed regardless. That front tranny seal will get splashed in oil when running anyway. And unless you have uber, uber flat land, you're always going to be going up and down hills during any normal use. I know certainly on our land doing any task - raking hay for instance - every three minutes you're running down a hill at about the same slope as any ditch. Not a big deal if so - only takes a couple hours to split an N.

 

[Noelie84]

I'm not worried about oil loss; I'm going to drain and clean the housing out while I've got the shaft out anyway. Whenever I get a new-to-me piece of equipment I always change all of the fluids anyway so I have a baseline. I just don't want to change them twice because of a do-over if I can avoid it.

 

[Jim in LA]

There are lots of differing opinions on ORC's. Some folks will disagree with me, but I never saw why folks get so hot/bothered about them. Here was my note about them on another thread about pretty much the same subject not long ago:

"Even if you want an over-running clutch, I'd still swap shafts and get a standard 1-3/8" to 1-3/8" overrunning clutch. But frankly, I never understood why so many folks get so hot/bothered about having over-running clutches on N's. All N's (and most other makes/models through the 1950's) had geared PTO. And folks used (and most still use) them without overrunning clutches for everything - typically for much heavier and higher-inertia work than what most people are using an N for today. True, if you happen to be driving at top speed toward a brick wall with a bush hog and hit the clutch to stop when you're only 4' from the wall, the mower's rotary inertia will drive the tranny and keep you moving forward for a few feet and you might hit the wall. An overrunning clutch will prevent that. But another way of preventing that is to just not be driving towards a brick wall at top speed with a bush hog and only hit the clutch to stop when you're only 4' away. Drive and operate your implements with some common sense and there's no reason you need an overrunning clutch."

My '51 still has the small PTO shaft and a wellworn ORC on it. I need to break down and upgrade to the 1 3/8 shaft.

 

[MeanGene1]

My '50 still has the original small shaft and the ORC I put on it 15 years ago to run the rotary mower. Still works fine, not sloppy or wobbly in any way, and I see no reason to change it until something goes wrong, at which point I would then replace it with the larger shaft- but not just because someone else says it's "goofy" and I "need" to- sheesh...

 

[Noelie84]

Replacing it makes sense to me, in my situation. I'm already in there replacing a leaking seal. While I'm at it I'd also do the bearings anyway; no sense putting it back together with old components. It doesn't cost much more $ to just buy the upsized shaft kit. And it'll save me from having to buy new PTO shafts if I feel like using this tractor to run the implements that I already own and use with my other tractor. If yours still works fine, then I agree, you shouldn't replace it. If I weren't already tearing mine apart, I probably wouldn't either.

 

[TJ64]

That's an idea, but the ditch in front of my house is about 8 feet deep, so I don't know if I'd be able to get the tractor back out after I replaced the seal!

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[Richard G.]

My '50 still has the original small shaft and the ORC I put on it 15 years ago to run the rotary mower. Still works fine, not sloppy or wobbly in any way, and I see no reason to change it until something goes wrong, at which point I would then replace it with the larger shaft- but not just because someone else says it's "goofy" and I "need" to- sheesh...

My 52 still has the small shaft and ran a Woods brush hog for many years.
If the tractor could push it down, it got hogged.
I broke the stump jumper one time on an oak tree.
It runs a 5 ft finish mower every summer now and still keeps on going.
Tractor has been in the family since new.
I have rebuilt the engine 6 times since I was 14 years old.
Tractor is the same age as me.
I have a spare small shaft that somebody gave me that I will use if it ever breaks.
I just bought another 52 8N that the tach works on and it has 2800 hours.
It runs and looks great and has the small shaft.
Richard in NW SC