pinion seal (1 Viewer)

[Southbound]

So I've already decided to do a knuckle rebuild and am wondering if I should address a pinion seal leak at the same time. I don't even know where the pinion seal is, I just know my mechanic said it's leaking. I'm thinking if I'm taking everything apart anyway for the knuckle rebuild it shouldn't be that much more effort to replace the pinion seal. Or is it? I started reading some of the threads on pinion seals and it sounds like I have to take the whole drive shaft out to do it. I don't know, is it worth it? I just wish I had a better idea what I was getting into before getting into it!

 

[Mace]

Umm, if your pinion is leaking you probably have a bad pinion bearing.

The pinion seal is behind the flange that the Driveshaft bolts to.


get under your truck and grab a hold of the driveshaft. Wigglt it back and forth (wiggle, not turn) if it has any play, you need to rebuild your diff. Tightening the nut sometimes works but if you are in it for the long haul, just replace the bearing..

 

[Jan-78FJ40]

So I've already decided to do a knuckle rebuild and am wondering if I should address a pinion seal leak at the same time. I don't even know where the pinion seal is, I just know my mechanic said it's leaking. I'm thinking if I'm taking everything apart anyway for the knuckle rebuild it shouldn't be that much more effort to replace the pinion seal. Or is it? I started reading some of the threads on pinion seals and it sounds like I have to take the whole drive shaft out to do it. I don't know, is it worth it? I just wish I had a better idea what I was getting into before getting into it!

the pinion seal is between the input of the 3rd member (differential) and the attachment for the driveshaft (pinion flange). It is not hard to change. Basically, take the drive shaft off (you'll need two 14mm wrenches) on the side of the differential. when that is off, you'll see a big washer'lock nut in there (I think it is 34mm, but I am not sure). take that off, then you can slide the pinion flange out. underneath you'll see the seal. pry it out, and put a new one in. it can be a pain to get the new one in. it helps to have the old seal-put it over the new one, and use a rubber mallet to get the new one in-hammer just on the old one.
then put the pinion back on, adjust the torque with the lock nut, stake it, and you're done.
at least that's how it works on my 84.
hth
j

PS. and always listen to Mace!

 

[Mace]

PS. and always listen to Mace!

Great description

But that last part is not the best advice

 

[Poser]

Does your engine leak oil?


Do you change your own oil? If so, do you clean up all the oil that possibly leaks from the filter when it is removed?



The supposed leak could be from other oil, and not the pinion seal....


More that a couple trucks have come into the shop with the owners stating that the front pinion seal is leaking, only to clean the area up and realize that it is not the pinion seal, but engine oil.


Just another thought....


Good luck!


-Steve

 

[Southbound]

Thanks guys. I'll try that Mace. Do I check for play with the truck on the ground or when it's on stands? Would there be any other indication I have a bad pinion bearing other than the seal breaking?

I do have a small oil leak and it would sure be nice if that's it. I'll clean up that whole area and see what happens.

Thanks again.

 

[Mace]

A leaky seal is one of the best hints at a bead pinion bearing. So check it to see if it has any play in it.

BUT, like Poser said, if it is motor oil instead of gear oil, you are fine

 

[lovetoski]

This might be a dumb question, but did your mech say it was the front pinion seal that was leaking? Most 60's don't use the front drive-shaft much - so is it possible he was referring to the rear pinion seal?

 

[lowtideride]

If it was the front....Poser is prob. right.

 

[Southbound]

No, it was definitely the front pinion he was talking about. I was with the mechanic underneath the truck when it was on the lift. He pointed in the general direction of the front diff and said "see all that oil and grease mixed? Looks like a bad pinion seal." All I saw was a thick coating of greasy sludge...

So are you saying 60's don't use the front drive shaft much because it is only engaged when in 4x4 mode?

 

[lowtideride]

Yulp...Poser was right....

 

[lovetoski]

So are you saying 60's don't use the front drive shaft much because it is only engaged when in 4x4 mode?

Yup.

 

[fliphkd778]

Okay, so somehow I'm missing the directions on changing one of these out.
1. Removed axle.
2. Saw a 30mm nut(most mud threads refer to it being a 32?)
3. It hardly had any torque at all on it, so I easily removed it.
4. Then the pinion seal is supposed to be right under that collar?
5. This is what I saw:

 

[agent orange]

Thats it, the seal sits in a recess in the end of the third. Stick a little pry bar under it and lever against the opposite side, it will come out.

BTW, there should be like 200+ foot pounds on that nut. The lack of any preload is why the seal went bad, and probably means the pinion bearing is at the very least worn if not on its way out.

EDIT: Of course, all of that is assuming it was actually leaking.

 

[fliphkd778]

Much thanks.
Yes, it leaks everywhere.
I've heard that the splined shaft in the photos shouldn't have any play in it? Otherwise indicating a bad bearing?

 

[fliphkd778]

I don't know about you, but mine's stuck bad.
I put a big old pry bar in there, but it just bent.
I better just take of the 3rd....

 

[fliphkd778]

I know it's been a while, but it wasn't leaking all that bad so I let it go for a while.
Now I'm back at it, and running into the same issues.
So far, my axle has been different in several ways, my pinion nut was a 30mm instead of a traditional 32, there was no wire-locked nut as shown in the sor diagram, and my input flange is different too.
-Can the third just be pulled at once? I loosened all 10 or so around the circumference and drained the oil, but it's sort of stuck coming out

 

[cruiser88]

I know it's been a while, but it wasn't leaking all that bad so I let it go for a while.
Now I'm back at it, and running into the same issues.
So far, my axle has been different in several ways, my pinion nut was a 30mm instead of a traditional 32, there was no wire-locked nut as shown in the sor diagram, and my input flange is different too.
-Can the third just be pulled at once? I loosened all 10 or so around the circumference and drained the oil, but it's sort of stuck coming out

Yes you can pull the hole third at once. Yep it will be stuck fairly good so wuth some elbow grease and a big @#$%^& hammer it will come out

 

[exrsa1]

I know it's been a while, but it wasn't leaking all that bad so I let it go for a while.
Now I'm back at it, and running into the same issues.
So far, my axle has been different in several ways, my pinion nut was a 30mm instead of a traditional 32, there was no wire-locked nut as shown in the sor diagram, and my input flange is different too.
-Can the third just be pulled at once? I loosened all 10 or so around the circumference and drained the oil, but it's sort of stuck coming out

Sorry if I missed something, but you do have the axles pulled out, right? If so, just put a jack under the front of the diff and slowly put pressure on I till it breaks free. It is heavy, so be ready to handle that when it comes out. Also, pulling the diff is not going to make this an easier job to just change a seal.

Ex

 

[fliphkd778]

I'm sorry; it seems CCOT sent me the wrong part. The one they sent me was the wrong dimensions, leaving me questioning where it went. The correct one I got from my local parts shop, a National/Federal Mogul #1177. High quality, same as oem.