Leaking 9" Rearend
Freshman User
Joined: Feb 2002
Posts: 25
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Leaking 9" Rearend
I have a 79 150 with a 400m, C6, 4" lift and 35" tires.This truck is clean and i'm very happy with it. During the ten years I've had it the right rear axle seal at the wheel has leaked and been replaced about 3 or 4 times. I just came back from a 300 mile round trip and underneath well what a mess. Its leaking again. Could there be another problem? I would really appreciate some help or ideas. Just for info its the 9" rear. Thanks
New User
Joined: Dec 2001
Posts: 22
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Leaking 9" Rearend
Everytime I've seen a leaking rear axle seal it usually means a worn bearing. If your axle isn't true or the spindles are worn it could also cause a leak and/or worn bearing. Make sure you've torqued the axle bolts to the correct spec.
Elder User
Joined: Jan 2002
Posts: 593
Likes: 1
From: Texas panhandle
Leaking 9" Rearend
I have a 78 F-150 4X4, 3.50 gears. It leaks out the left rear wheel. I replaced the bearing and seal (about 80 bucks) and it still leaks. It has the tapered roller bearing so the seal is on the outside just under the bearing retainer. Has any one replaced this tapered roller bearing with a roller style bearing with the seal on the inside of the bearing? Either style bearing was available. The tapered roller is a good idea but the seal doesn't work. Thanks for your input.
Fleet Owner
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
Leaking 9" Rearend
Scott, You could have another problem, I did. On the drivers side of the center section, there is a rubber hose connected to a block that the brake lines run through. This is a vent for the axle housing and likely is plugged up. Cut the rubber hose about 1" up from the axle and use a small drill bit and twist it (by hand)in the hole to clear out any dirt. Stopped me from replacing seals. 
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John
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John
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In the cool still quiet of night, you can hear chevies rusting away.
New User
Joined: Feb 2002
Posts: 1
Likes: 0
From: Page USA
Leaking 9" Rearend
I have a 1978 F100 with freshly rebuilt 400, C6 and 9 inch rear axle. I am about to make the 1000 mile return trip to beautiful Lake Powell from Moses Lake, WA. On my way up to WA, I had a problem with my rear axle leaking from both sides. I pulled out the axles last night and had the bearings removed from them today. I ordered some new bearings and seals to instrall on the axles. The old bearings were a tapered design with a seperate race that stayed inside of the axle. The new ones are all one piece with the outside race portion as part of the bearing assembly. They came with new sleeves to hold them on. The seals that I was provided are the same as the old ones that I removed. I was wondering if this bearing was just some type of running change to something newer and better. I am going to remove the old race and compare measurements but was interested in some other input.
Thank you, mike
Thank you, mike
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Senior User
Joined: Jul 2001
Posts: 352
Likes: 0
From: Palatka, FL
Leaking 9" Rearend
I also have the same problem on my '81 9 inch. It leaks no matter what from the right side and when i had it rebuilt the shop said that the old bearing had spun the race and chewed up the housing. I find this hard to believe what about you guys? Also, is the axle vent tube supposed to be a hole straight through the axle tube with a hose attached? Or is there some sort of valve in there?
Thanks,
Josh
Thanks,
Josh
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Fleet Owner
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
Leaking 9" Rearend
Josh, It was just a hole on my 66. I put three seals in and it wouldn't stop leaking. I read a post here about clearing the vent hole. I crawled under the truck and was begining to think that the poster was crazy, until I took a very small drill bit in hand and began twisting through tightly packed dirt. I don't have a wheel leak there now.
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John
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[link:www.ford-trucks.net/users/jowilker/NCFTE.html|NCFTO] North Carolina Ford Truck Owners Group
In the cool still quiet of night, you can hear chevies rusting away.
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John
jowilker email me
[link:www.ford-trucks.com/users/jowilker|My Club FTE Page] Member since 01 01
[link:www.ford-trucks.net/users/jowilker/NCFTE.html|NCFTO] North Carolina Ford Truck Owners Group
In the cool still quiet of night, you can hear chevies rusting away.
Posting Guru
Joined: Aug 1999
Posts: 1,485
Likes: 3
Leaking 9" Rearend
Guys, John is right, if that vent is plugged the seals WILL leak. That should be the first thing you check if an axle is leaking. It could save alot of time and money on repairs that still wont seal.
Nathan
Nathan
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