8N Axle Seals / Brakes

[DaleM 498N]

Hi All, it's been a while... I'm into my 8N brakes AGAIN due to left one being oil soaked. This is probably my 4th time doing this job in the 20 years or so I've had my 'N ('49 S# 8N183785). I get the exact same oil leak each time. It appears oil leaks past the lip seal which rides on the hub and ultimately soaks everything. All the other leak paths (gaskets, bolts, retainer flange, etc) seem tight and dry with no leakage. I attached some pics below. Looking at my I&T manual as well as other exploded views, and reading some past threads here, leaves me a little confused. Different drawings show an INNER Oil Seal (8N4233A). I cant figure out what this seal is and where it goes. It appears to be located INSIDE of the axle bearing. I have no axle seals anywhere between the bearing and the differential, and I see no place where one would reside. The seals I have are captured in the attached Parts pic: The lip seal (outer seal) which is pressed in the Retainer, the gasket between the lip seal and the Retainer, a cork gasket which compresses between the face of the Bearing retainer assembly and the back side of the lip seal retainer, and a cork seal that slides over the axle splines and is compressed between the inner face of the hub and the bearing (i don't see that this seal does much of anything,..). Items to note: My hubs are tight on my splines. They are not worn and tighten up extremely well. All of the oil leakage shows up inside the brake drum. My rear end oil has pretty much direct access to that outer lip seal. My axle bearings are shimmed per procedure for the proper "endplay". I can send other pics as needed.

Now the questions: Am I missing any seals? Should I have oil from the rear end reaching my axle bearings, or is the bearing supposed to not see oil and be lubed with grease only? Regarding oil soaked (for months) brakes, has anyone had luck with cleaning them up with Brakekleen and re-using therm?

Thanks, Dale M

 

[deanostoybox]

From:
Tractor Identification and Model History - Ford Fordson Collectors Association

At serial number 245261, nearly the end of '49 production, an inner grease seal was added to the rear axle housing to help stop the common problem of gear lube leaking onto the brakes. New axles were required to accommodate the new seals.

 

[DaleM 498N]

Appreciate the info. As I did more searching, I recognized the inner seal was added at some point - good to have it confirmed that it came after my machine was built. I also realized its been over 10 years since I last did that left brake / seals, so I guess the existing seal lasted a half decent amount of time. Still seems odd that a lip seal goes bad in that timeframe with extremely slow rpms on the shaft and relatively no time compared to say the lip seal on a rear car axle. I keep thinking I'm missing some "cause", but just cant see it. Thanks again. Dale

 

[DaleM 498N]

P.S - looked at your referenced website - a great reference and site - thanks!

 

[wore out]

Appreciate the info. As I did more searching, I recognized the inner seal was added at some point - good to have it confirmed that it came after my machine was built. I also realized its been over 10 years since I last did that left brake / seals, so I guess the existing seal lasted a half decent amount of time. Still seems odd that a lip seal goes bad in that timeframe with extremely slow rpms on the shaft and relatively no time compared to say the lip seal on a rear car axle. I keep thinking I'm missing some "cause", but just cant see it. Thanks again. Dale

Do you have the axle endplay set to just a few thousandths?

 

[Btzj02]

DaleM, I thought I would ask, when adding transmission/hydraulic oil to your 'N do you remove the lower bolt on the inspection cover and only fill to that point instead of using the dipstick level as a fill point? That may help minimize the oil getting to your brakes.

 

[DaleM 498N]

Wore Out, my endplay is such that with rear end on jacks, I just get both tires to turn same direction when rotating one of the tires. I can still rotate tires opposite directions with little force, so I am not overly tight.

Btzj02, my oil level is kept to my dipstick full level mark. That said, I absolutely have oil setting at my axle bearing seals most times. From your question, it sounds as if there is a recommendation out there to keep the level a bit lower such that only on side slopes would some oil run out to the seals????

 

[chetswen]

I did the fix recomended by member Zane. It's been 17 years and still oil free brakes. The one thing I did differantly was to install a 1/4" pipe plug on the top and bottom of each trumpet. By installing the silicon caulk through the bottom hole, I was sure I got a good seal when it oozed out the top hole. You will need to pack your bearings as they will no longer get lubercation from the sump.

https://forums.yesterdaystractors.com/threads/lack-of-inner-axle-seal-for-early-8n.419991/#post-1954265

 

[Btzj02]

Wore Out, my endplay is such that with rear end on jacks, I just get both tires to turn same direction when rotating one of the tires. I can still rotate tires opposite directions with little force, so I am not overly tight.

Btzj02, my oil level is kept to my dipstick full level mark. That said, I absolutely have oil setting at my axle bearing seals most times. From your question, it sounds as if there is a recommendation out there to keep the level a bit lower such that only on side slopes would some oil run out to the seals????

Next time you fill with oil remove the lowest bolt on the hydraulic sump inspection cover. Fill only until oil comes out of that hole. Let the system equalize/drain for a few minutes before replacing the bolt.

 

[Jim L WA]

Dale M, check out paragraph 134 of your FO manual. I think you have your bearings adjusted too tight.

 

[DaleM 498N]

Jim, I see that. I will check to see what I have now. Last time I adjusted endplay was about 10 years ago when I last did brakes / seals. I was going off of memory on how to shim properly, so I may have just messed up what I said. I think what I may remember is removing shims till wheels turned together, but not the follow-up part of adding a few thousandths back in to give them a touch of spacing. I will verify I'm not too tight and wheels spin opposite. Thanks!

 

[YosmiteSam]

I would never put STP in an engine, but I do routinely do put a small amount of it into every gearbox and axle I work on because it has a stop leak quality to it. I think it's good for seals and rubber things.

For that size axel I would pour in a half a bottle of STP. About a quarter of a bottle for a transmission. A quarter bottle for a car or pickup axel. About an ounce of it in a steering box.

I use it as the assembly lube and then pour in the rest of it in the case before adding the gear lube.