Leaking Input Seal 9" Rear

bamcoc5 · #1 (**permalink**) 04-11-2006, 10:52 PM

My rear has a leak coming from the input seal. I understand there is an oring in there. This rear was refurbished and shortened. The rear has never been run just rolled around. I purchased this rolling chasis from a member and don't know if he over filled the rear. Should I empty and refill or open and change the oring?

LMH · #2 (**permalink**) 04-11-2006, 11:37 PM

If it's over filled, I doubt that is causing the leak unless it's coming from the vent. So I would say the seal(s) needs to be changed.
You can pull the fill plug and see how full it is. Trust me, if it's over filled, you'll know as soon as you take that plug out!
Larry

Rick Parker · #3 (**permalink**) 04-11-2006, 11:42 PM

The fill point will not allow the level to go high enough to go out the seal. There is no "O" ring on the input fill, it is a tapered pipe plug on the LH side of the differential housing, there is no drain plug unless one has been added. There is however an "O" ring about 5" in diameter that surrounds the pinion support casting. That is the part that has 5 bolts holding it to the main differential casting and has the U joint yoke. It is quite possible to damage the "O" ring while installing the Pinion support into the differential casting. It is suggested to apply some grease on the "O" ring and surrounding area and carefully check it (the O ring) all the way around as the Pinion Support is slipped into the casting. Wipe the bottom of the housing so it is free of any oil, check it again later and you will probably find that the seepage is coming at the parting line between the main casting. Newspaper and Baby Powder can be used to track leaks too.

trularin · #4 (**permalink**) 04-12-2006, 06:48 AM

Unbolt the axels and pull them out enough to allow the rear to be unbolted.
Remove the nuts that hold the pig in place.
crack the seal and pull the pig.
On the bench, scrap the gasket that goes between the pig and housing.
Unbolt the retainer and remove from the pig.
Secure a new seal, crush sleeve ( if you have one ) and retained gasket.
Replace seal. Use caution as you may mess this up if you are "happy" with a hammer.
Reassemble the pinion to the retained and torque to spec.
RTV on ONE side of the retainer gasket and allow to dry.
Grease the other side of the retainer gasket and reassemble.
Check vent tube and verify it vents.
RTV pig gasket to pig, allow to dry.
grease other side of pig gasket and reassemble pig to housing.
Pul it all back together, fill with the lube of your choice. MAKE SURE you add posi fluid.

Hope this helps.

Clois Harlan · #5 (**permalink**) 04-12-2006, 07:02 AM

Nice instructions Dave...but what is a pig?

bamcoc5 · #6 (**permalink**) 04-12-2006, 11:24 AM

Thanks to all that replied. The leak is not coming from the the large gasket on the PIG, but from the pinion drive shaft input. Do I really have to pull the axlesshafts to remedy this problem? I have a 9" rear break down. It shows right behind the the drive shaft input flange a seal and oil slinger. Could this be the culprit for the leak? This seal appears to be similiar to the output seal on a TREMEC TKO TRANNY. I have not install the driveshaft yet. What I am getting at is with the drive shaft being absent does this put pressure on that seal rolling the chasis in and out of the garage?

Herkypilot · #7 (**permalink**) 09-02-2006, 06:36 PM

I have the same issue - rebuilt Ford 9", no driving time on it and it had a slow leak. I pulled the pinion this weekend with the intention of changing the seal and here's what I found...on the back of the pinion there is a flange which had a groove worn in it. Not much of a rebuild if they didn't catch this on break-down.

Herkypilot

Herkypilot · #8 (**permalink**) 09-02-2006, 06:39 PM

Another post on a build forum said you can buy a stainless steel sleeve to repair this at your local auto parts store for about $20.

Herkypilot

jwd · #9 (**permalink**) 09-02-2006, 06:59 PM

Quote:

Originally Posted by Herkypilot

Another post on a build forum said you can buy a stainless steal sleeve to repair this at your local auto parts store for about $20.

Herkypilot

Steve, Oh yea of little faith, the part number is BCA 99181. They are commonly called Redi-sleeve. Unfortunately there has been a price increase since the last time I bought one (4 years ago). They are now $30 but Rockauto.com has them for $23. I forgive you for doubting me.

Jim

Herkypilot · #10 (**permalink**) 09-04-2006, 05:43 AM

Ah, I didn't doubt ya, I wanted to do a little research to see if others have run into this problem.

Hope you don't mind me pass'n along your words of wisdom on this fix. Adv. Auto sells the sleeve for $27. NAPA wanted $37. I'm suppose to go pick it up this morning from Adv.

Steve

sharpe 1 · #11 (**permalink**) 09-04-2006, 06:58 AM

Down south when I was a kid, the differential was called a hogs head.

sharpe 1

jwd · #12 (**permalink**) 09-04-2006, 07:01 AM

Glad I could help. Be sure to use lots of lube/grease on the seal surface and the new sleeve before replacing the yolk. If you don't, you'll be replacing the seal again in a few miles. Don't ask me how I know this.

trularin · #13 (**permalink**) 09-04-2006, 07:11 AM

The Pig, is the center section where the ring and pinion are mated to drive the axels. Sorry gents, thought everyone knew what a pig was when talking about ford nines.

Clois, I hope you and your wife are having a nice day.