Rear seals

[Cooter143]

I have a "50 8n that has both rear seals leaking, and no brakes. I took it to a guy to have it fixed, the brakes worked for a few days then quit and oil was leaking onto the rear tires as much as ever. Not much luck getting him to fix it, so I decided to tackle it myself. I pulled everything off and am not sure what I need to order, I got a little confused looking thru the parts on this site so I attached a pic to show what I have. Hubs were on tight, had to use puller. Didn"t find any gaskets installed. I do have a manual, and have looked at John Smith"s site, but am still not sure what parts I need. Any help would be appreciated?

 

[Cooter143]

Trying to post the pics.

 

[Cooter143]

.

 

[L.B,]

Theres lots of info & help here, however nothing beats a book its there 24-7. I don't know how to fix your problem so I will butt out. Except get ya a manual.

 

[Bulldozer]

If you have a 1950 N series, there is an inner and outer rubber lip seal.

The outer seals the wheel hub.
The inner seals the axle.

The 1948 & 1949 only have the outer seal, only.

With the 1950 you need the following soft parts for each wheel.
1. A8NN4248A, outer seal assembly with steel retainer. The seal ,D5NN4115A, can be purchased separately with the gasket,8N4290, and installed in the old steel retainer, but the cost difference is quite small.
2. 8N4225, cork gasket larger dia.
Sandwiched between A8NN4248A and the brake
assembly backing plate outer surface.

3. 8N4284, cork gasket small dia
This is a critical gasket on the 1948 & 1949,
since this gasket prevents leakage through
the path formed from the hub spline and axle
spline. Sealer like permatex #2 is applied
to this gasket. The gasket is sandwiched
between the end of the wheel hub surface and
the bearing cup. When the wheel nut is
tightened this gasket is compressed.
4. 8N4233A , inner rubber lip seal.
This seal is used with 1950 and up.
It installs in the bearing cup retainer.
The axle bearing retainer must be removed to
install this seal.

Note there is no gasket between the braking plate inner surface and bearing retainer outer shoulder.

Prefer using permatex #2 sealer non hardening type on the gaskets. Some folks prefer silicone RTV.

Some folks believe the leakage is reduced by applying addtional torque on the axle nut. If the hub is loose on the axle, tightening the axle nut will compress the 8N4284 cork gasket and help reuce leakage.

The inner rubber lip seal is a second line of defense against leakage. If the journal on the axle is worn, a new gasket will not help.

Remember, if the bearing retainer is removed, reshimming the preload on the axle bearing is required because the multiple thin paper shims will be destroyed when the retainer is removed.

The easiest method is to leave the inner seal alone and apply abundant mount of sealant to the cork gasket 8N4284.

If the inner seal does leak, you are now in the same boat as the 48/49 crowd.

 

[DollarBill]

Cooter, here's a photo of the seal contact areas - As indicated in the photo, there are three; inner, cork and outer seal. Since it's already leaking, I recommend replacing all three.

Polish both the hub and the axle with Scotch Brite to provide a good seal.

I always use Permatex to seal the metal part of the seal to its receptacle.

Don't forget to pack the outer bearing before reassembly.

 

[Kurt-NEPA]

John Smith did a great job on describing a rear seal replace on an 8N. I followed his procedure on mine and its been leak free for 3 years now.

Give "OldFordTractors" a look. And if John comes along - Thank You!

http://www.oldfordtractors.com/rep.htm#q15

 

[carlntexas]

(quoted from post at 11:12:00 06/22/13) John Smith did a great job on describing a rear seal replace on an 8N. I followed his procedure on mine and its been leak free for 3 years now.

Give "OldFordTractors" a look. And if John comes along - Thank You!

http://www.oldfordtractors.com/rep.htm#q15

Also like to thank John for his advice used it about 5yrs ago and my 49 8N is leak free and stops on a dime.

 

[Cooter143]

Thanks to all, great info. It all makes more sense now, I was just a
little confused by the FO-4 diagram when I tried to compare it to
the parts list. I have a "50 motor on this tractor but I guess the
axles are older because it doesn"t have the inner seal. The leak was
coming from between the outer seal assembly and the brake pivot
plate. For some reason the guy that put new seals in it didn"t put
Permatex between those two. I bought new seals but I think that
gap with out sealant was the problem. I really appreciate
everybody"s help. This site always has the right info and has given
me confidence to tackle more problems than I normally would.

 

[Hobo,NC]

(quoted from post at 07:58:57 06/23/13) Thanks to all, great info. It all makes more sense now, I was just a
little confused by the FO-4 diagram when I tried to compare it to
the parts list. I have a "50 motor on this tractor but I guess the
axles are older because it doesn"t have the inner seal. The leak was
coming from between the outer seal assembly and the brake pivot
plate. For some reason the guy that put new seals in it didn"t put
Permatex between those two. I bought new seals but I think that
gap with out sealant was the problem. I really appreciate
everybody"s help. This site always has the right info and has given
me confidence to tackle more problems than I normally would.

Good follow up,,, you can leave that gasket out if you run a good bead of RTV there on final assy once you have the pre-load set up correct...

If it has the original rubber seal (cork seal marked in blue) I re-use it I don't care much for the cork type... It's only to seal the splines so a little RTV is insurance...