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I noticed that I have a very small leak coming from my pinion seal, running down to the driveshaft and it will occasionally sling it. If I let the car sit for a long period of time, there never is any gear oil on the ground, so I assume its the pinion seal. The gear oil definitely is running down the third member and I need to fix ASAP.

I've read conflicting posts where some say I have to replace the crush sleeve, and others say you don't that you can just replace the seal and re-torque it.

1. Do I have to replace the crush sleeve?
2. What are the torque specs for torquing it once I replace the seal?
3. Is this a relatively easy install, or should I take it to a specialist?

I'll take any pointers I can get. Thanks!

Tim
 

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Replacing the pinion yoke seal is too easy.

Detach drive shaft from pinion yoke.
Hold yoke with special tool or larger wrench and remove nut.
Remove pinion yoke.
Remove seal.
Install new seal.
Install pinion yoke.
Install NEW pinion nut, torque to 125 ft-lbs.
Install drive shaft.
Drive car.

The whole job should take under two hours.
 

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Discussion Starter #3
Too easy!

Any particular brand and part number? I'm having trouble locating the 8" seal. Thanks!

Tim
 

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Sounds like yours is leaking out the threads, common problem. When you replace the seal clean the pinon threads and put sealer on them. I have used silicone, gasket sealer, pipe thread sealer.

I mark the nut before removal and install to that mark and make it a just a hair tighter (a blonde hair). I would use the old nut, the reason is you trying to get it back to exactly were it was and just a couple of thousands past that to maintain the same preload

I fixed mine without removing the flange just cleaning the nut and threads and applying sealer. The key here is it slings it while rotating

Larry
 

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Really? Rock has oodles of them.
I forgot to check there and was trying to find them at Summit. Do the 7.25" and 8" use the same seal? I think that is what was throwing me off, but I used Rock Auto as a cross reference and ordered it from Summit.

The install seems relatively simple and I appreciate everyone's help. I've got a laundry list of things I am doing while I pull the motor, which will hopefully start today. I've got boxes and boxes of parts that need to go on. Thanks again!

Tim
 

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No, the 7", 8", and 9" all use different seals. Oddly, they all use the same pinion nut. So do newer Ford axles. Seems odd, but a 65 with a 170 I6 and 2.77 trans uses the same pinion nut as a 1970 BOSS 429.

Don't bother with marking the flange, nut and shaft. Too easy to screw that up. Just torque a new nut to 125# and you are done.
 

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No, the 7", 8", and 9" all use different seals. Oddly, they all use the same pinion nut. So do newer Ford axles. Seems odd, but a 65 with a 170 I6 and 2.77 trans uses the same pinion nut as a 1970 BOSS 429.

Don't bother with marking the flange, nut and shaft. Too easy to screw that up. Just torque a new nut to 125# and you are done.
I earned a living for 47 years doing it that way and never ruined a set of pinion bearings.

In the Ford shop Manuel there is no spec for a used crush collar only a new one that they say to start at 175 ft lb and start checking preload.

How did you arrive a 125 ft lbs

Larry
 

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I've done a few, always with excellent results. My Mountaineer has a replaced seal with over 100,000 miles on it using that trick, which I learned from a friend who started his own speed shop business over 25 years ago. Not an easy business to stay that long. He rebuilds differentials for laughs. Has probably used that trick thousands of times. To answer the question directly, it was arrived at by experimentation and experience. 125, (assembling with a new crush is 175) with a new nut, is enough to seat firmly on the crush collar without increasing the amount of crush, seats and preloads the bearings. The new nut assures seal, and accuracy of torque.
 

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One thing I've learned there different ways to do things. I built hundreds of rears over the span of my career, trained many in this profession and my method works well and is easily taught to people coming into the auto repair business.

Mark it with a punch and very easy to repeat, I always apply some type of sealer to the threads because they will leak and sling the oil.

Larry
 

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Do you really need to remove the yoke to replace the seal? Why not just unbolt the flange and slide the whole pinion assembly out, change the large o-ring seal and reattach? That way, no change to the bearing preload, right? Just need to make sure you keep the shims in place to preserve the pinion depth.
 

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I've been following this thread as I'm in the middle of doing this myself on the 8.8 Explorer rear I'm going to use. Should have done this when I did the axle bearings/seals. Oh well. I'm at having everything apart and cleaned up, smooth surfaces all around. I have found other how-to's on this and although there are some necessary similarities between them, there seems no predominant way, different ways to go about it. Again, oh well. I'm gonna finish this later today come hell or high water, and here's the plan;
I marked the pinion, yoke, etc., and counted how many turns to remove the nut. I'm gonna reuse that nut, seems in great shape. When I reinstall I'll count the turns again and see where the torque is when I get there. Anything less than 125lbs is gonna get additional effort. Permatex, Loktite, and grease in their respective areas. Here's hoping that'll do.
 

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Do you really need to remove the yoke to replace the seal? Why not just unbolt the flange and slide the whole pinion assembly out, change the large o-ring seal and reattach? That way, no change to the bearing preload, right? Just need to make sure you keep the shims in place to preserve the pinion depth.
What you describe is ten times as much work, and it's NOT an o-ring seal. It's a regular steel-backed neoprene lip, impossible to replace without removing the yoke. You're talking about the pinion housing seal, not the pinion seal.

 

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Do you really need to remove the yoke to replace the seal? Why not just unbolt the flange and slide the whole pinion assembly out, change the large o-ring seal and reattach? That way, no change to the bearing preload, right? Just need to make sure you keep the shims in place to preserve the pinion depth.
What you describe is ten times as much work, and it's NOT an o-ring seal. It's a regular steel-backed neoprene lip, impossible to replace without removing the yoke. You're talking about the pinion housing seal, not the pinion seal.

Ahh, got it. I was thinking the leak was happening around the large o-ring, not around the pinion shaft. My mistake.
 

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…here's the plan;
I marked the pinion, yoke, etc., and counted how many turns to remove the nut. I'm gonna reuse that nut, seems in great shape. When I reinstall I'll count the turns again and see where the torque is when I get there. Anything less than 125lbs is gonna get additional effort. Permatex, Loktite, and grease in their respective areas. Here's hoping that'll do.
The upper lip on the self-locking pinion nut may look groovy, but after one use is a looser fit than when new. Plus, the thread sealant is gone. Buy a new one. We're talking $2.65 here.
 

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The upper lip on the self-locking pinion nut may look groovy, but after one use is a looser fit than when new. Plus, the thread sealant is gone. Buy a new one. We're talking $2.65 here.
One (at least) of the how-to's took the looser fit of a reused nut into account and said to tighten it slightly past its previous mark, no mention of torq-spec. But OK, I'll run get a new one as you suggest. Just so you know though, $2.65 here, $2.65 there, pretty soon you're talking real money. >:)
 
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