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Discussion Starter · #1 ·
I need to replace the Pinion Oil Seal on the rear differential of an 82 Scrambler. Autozone has a set of directions for doing this, but they differ depending on whether the axle is a "Semi-Floating Axle w/Tapered Shaft" or "Semi-Floating Axles w/Flanged Shaft".

How do I determine if I have a tapered or flanged shaft?

Are the instructions good at the Autozone web page:
web page

Any recommendations on doing this job in general or specialized tools necessary?
 

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Re: advice request - Pinion Oil Seal on 82 Scrambl

If the axle's OEM Bone Stock it should be the AMC 20, with a Tapered axle shaft.
 

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I can not imagine how they would be different. yank one out, pound a new one in... isn't that it?
If the directios say to separate the splines on the axle, you better plan on buying new axle shafts after.. the 2pc axle shafts are probably the weakest like in your entire drivetrain and it's a good idea to replace them before they fail.
 

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Re: advice request - Pinion Oil Seal on 82 Scrambl

Welcome to the board! It must be tough getting parts out in the middle of the Atlantic. Congratulations on keeping your Jeep going! /ubbthreads/images/graemlins/grin.gif

And FYI, the way to tell the difference is to look at the wheel end of the shaft. If there's a dust cap about 2" in diameter and 2.5" long sticking out of the wheel center hole, you have 2-piece axels. If the dust cap is missing you will see a threaded stud and a big nut there.

But as Elusive says, it doesn't make any difference as long as the axel is the AMC model 20, which is the only common one with a circular cover. If the cover isn't circular, start over.

Unless . . . The SWB AMC20 uses a crush sleeve. Is it possible that the HD 20 uses shims instead? The procedure in the FSM is rather complex regarding how to replace the seal without disturbing the crush sleeve. If the pinion nut is overtightened the sleeve must be replaced. My FSM doesn't mention the HD axel - in '78 the FSJs used D44s and D60s.
 

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Re: advice request - Pinion Oil Seal on 82 Scrambl

Actually it does make a difference. If you have flanged shafts they you have a Dana 44 which uses solid pinion preload spacers. So all you would need to do is pull off the yoke, pry out the seal, add new seal, replace and retorque the yoke.

However, you will have a AMC20 which came stock with 2 piece axles. They used a crush sleave type pinion preload spacer. When you back off the pinion nut this spacer expands and you can not symply retorque, as this may not crush the spacer to its original size. On This or any other axle with a crush sleave, you need to do the fallowing.

1. jack up the rear tires.
2. Ideally you would remove the axle shafts, but I just back the break shoes off till the rear end turns ease.
3. Remove rear driveline.
4. Place an inch pound torque wrench on the pinion an measure the drag torque. Drag torque is the torque required to keep the pinion turning.
5. Remove Pinion nut. This will be very tight. You will need a large pipe wrench to hold the yoke and a large breaker bar for the nut. Nut size is 1 1/8".
6. Remove the pinion it should tap off with a hamer. Check the pinion seal surface for scratches and groves. If they can not be cleaned off with a light sanding then get a speedy sleave or replace the yoke. If the surface is damaged and not fixed you will be doing this all over again very soon.
7. Remove old seal, INstal new instal yoke, (I like to put a little RTV on the splines) and tighten the pinion nut to about 50 ft-lb, (you realy should use a new pinion nut).
8. Now you have to check the drag torque. If it is not enough tighten the pinion nut some more. Recheck continue till the drag torque back to original. Note, tightening the pinin nut takes a lot of force. Make sure you have a nice long braker bar.
 

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Re: advice request - Pinion Oil Seal on 82 Scrambl

Exactly so. AND if you overtighten the pinion nut, you MUST replace the crush sleeve, which is a whole 'nuther thing.
 

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Re: advice request - Pinion Oil Seal on 82 Scrambl

don't forget to run a drop or two of oil on the seal to yoke surface as not to accidentaly booger the new seal.

But unless your pinion Seal is really puking oil, or leaving a puddle everywhere you park, I wouldn't bother. I haven't come across too many AMC20's that didn't leak a little at the pinion.
 
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Discussion Starter · #8 ·
Re: advice request - Pinion Oil Seal on 82 Scrambl

Jim (and all),

Thanks for the info.

Please confirm that I don't need specialized tools for holding the yoke or pulling the pin seal or reinstalling the pinion seal as Chilton's recommends.

Thanks again!
Michael
 

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Re: advice request - Pinion Oil Seal on 82 Scrambl

[ QUOTE ]
Exactly so. AND if you overtighten the pinion nut, you MUST replace the crush sleeve, which is a whole 'nuther thing.

[/ QUOTE ]

For this step... use a NEW crush sleeve!
 

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Re: advice request - Pinion Oil Seal on 82 Scrambl

[ QUOTE ]
Jim (and all),

Thanks for the info.

Please confirm that I don't need specialized tools for holding the yoke or pulling the pin seal or reinstalling the pinion seal as Chilton's recommends.

Thanks again!
Michael

[/ QUOTE ]

Tools required:
Jack/Jack stands
Lug wrench
Inch pound Torque wrench
Big honking Pipe wrench or Air gun to get the Pinion nut off
Screw driver or pry bar to pull seal out
Seal driver or Big socket or something similar Diamter to the seal to drive it back in with less chance of boogering the seal.
Big Torque wrench (I'm thinking 250# but dont' quote me on that, check to make sure) to tighten the pinion nut back down.
Oh and a 1/2" wrench to remove the driveshaft.
 

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Re: advice request - Pinion Oil Seal on 82 Scrambl

[ QUOTE ]
Tools required:
Jack/Jack stands
Lug wrench
Inch pound Torque wrench
Big honking Pipe wrench or Air gun to get the Pinion nut off
Screw driver or pry bar to pull seal out
Seal driver or Big socket or something similar Diamter to the seal to drive it back in with less chance of boogering the seal.
Big Torque wrench (I'm thinking 250# but dont' quote me on that, check to make sure) to tighten the pinion nut back down.
Oh and a 1/2" wrench to remove the driveshaft.

[/ QUOTE ]

You can not get the nut off with a pipe wrench. The Pipe wrench is to hold the yoke from turning. It will take a 1-1/8" socket to reach the nut.
You do not need a big Torque wrench. The final torque on the pinion nut will be what it will be, the only thing that matters is that the drag torque is correct. You will be better off with a braker bar.
If you have a ubolt type yoke then you need a 1/2" wrench for the driveshaft. If you have the stock strap type then you need a smaller wrench and or socket, (I think mine was 5/16" but some are smaller, 1/4").
 

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Re: advice request - Pinion Oil Seal on 82 Scrambl

yep, thanks for the corrections, I started getting rebuild instructions mixed in my head... /ubbthreads/images/graemlins/tongue.gif

thanks
 

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Re: advice request - Pinion Oil Seal on 82 Scrambl

[ QUOTE ]
Actually it does make a difference. If you have flanged shafts they you have a Dana 44 which uses solid pinion preload spacers. So all you would need to do is pull off the yoke, pry out the seal, add new seal, replace and retorque the yoke.

However, you will have a AMC20 which came stock with 2 piece axles. They used a crush sleave type pinion preload spacer. When you back off the pinion nut this spacer expands and you can not symply retorque, as this may not crush the spacer to its original size. On This or any other axle with a crush sleave, you need to do the fallowing.

1. jack up the rear tires.
2. Ideally you would remove the axle shafts, but I just back the break shoes off till the rear end turns ease.
3. Remove rear driveline.
4. Place an inch pound torque wrench on the pinion an measure the drag torque. Drag torque is the torque required to keep the pinion turning.
5. Remove Pinion nut. This will be very tight. You will need a large pipe wrench to hold the yoke and a large breaker bar for the nut. Nut size is 1 1/8".
6. Remove the pinion it should tap off with a hamer. Check the pinion seal surface for scratches and groves. If they can not be cleaned off with a light sanding then get a speedy sleave or replace the yoke. If the surface is damaged and not fixed you will be doing this all over again very soon.
7. Remove old seal, INstal new instal yoke, (I like to put a little RTV on the splines) and tighten the pinion nut to about 50 ft-lb, (you realy should use a new pinion nut).
8. Now you have to check the drag torque. If it is not enough tighten the pinion nut some more. Recheck continue till the drag torque back to original. Note, tightening the pinin nut takes a lot of force. Make sure you have a nice long braker bar.

[/ QUOTE ]

Wow i think this is the first time, i have every seen this explained correctly. I made a lot of money rebuilding rears that techs just impacted the nut off and impacted it back on.

Only one other thing to add, make sure the inch pd wrench reads in low numbers. You will be reading under 10 inch pds. OK maybe two things. A click type will not work. A beam or dail is what you need. Dial is easier to read but much more money.
 

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Re: advice request - Pinion Oil Seal on 82 Scrambl

[ QUOTE ]
Wow i think this is the first time, i have every seen this explained correctly. I made a lot of money rebuilding rears that techs just impacted the nut off and impacted it back on.

[/ QUOTE ]

It's pretty much straight out of the Jeep Service Manual. "Tech" seems like too lofty a title for someone who can't read. /ubbthreads/images/graemlins/grin.gif
 

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Re: advice request - Pinion Oil Seal on 82 Scrambl

[ QUOTE ]
...Only one other thing to add, make sure the inch pd wrench reads in low numbers. You will be reading under 10 inch pds. OK maybe two things. A click type will not work. A beam or dail is what you need. Dial is easier to read but much more money.

[/ QUOTE ]

Use a beam torque wrench. This is the only place I recommend using a beam wrench. I hate beam wrenches, but a clicky torque wrench can be a disaster when doing this job.

Watch out for parallax when you read the beam. You MUST read it straight on, close isn't good enough for this measurement. It has to be exact!
 
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Discussion Starter · #16 ·
Re: advice request - Pinion Oil Seal on 82 Scrambl

All, thanks again, I have a few follow up questions:

One) Is it easy to gauge the drag torque (before / after new seal) with not being able to do a full 360 degree motions w/the torque wrench, due to the proximity of the muffler? (i.e. the muffler would get in the way of turning the wrench in a full circle)

Two) Are inch pound torque wrenches strictly in inches or due they go up to feet as well? (maybe a dumb question)

Three) If the rear-end has been low on gear oil for some hundreds(?) of miles, prior to me buying the scrambler should I check anything else in the differential before I change the seal? It seemed to be running fine w/out excessive noise. When I checked the lubricant for the first time it took close to 1/2 to 3/4 of a liter of gear oil. It appears to have dripped a little less than a 1/4 of a cup in 24 hours sit in the carport...

Thanks again,
Michael

Note: Since I am not actually in the midde of the Atlantic /ubbthreads/images/graemlins/smile.gif I updated my geography to Northern Virginia / DC area...
 

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Re: advice request - Pinion Oil Seal on 82 Scrambl

You've just got to work around everything, or move it. This is not something you just do by guess and by golly. You need a good view of the beam

For the crush sleeve you want a torque wrench calibrated in inch/pounds, not foot/pounds.

I'd just take a cursory look at the differential and if it ain't broke then leave it alone.
 

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Re: advice request - Pinion Oil Seal on 82 Scrambl

Are we making this to complicated? All the guy wants to do is change the pinion yoke seal. A smart guy, Pontiac59, once told me,"count the threads at the end of the pinion before you remove the nut, then match it after replacing the seal".
 

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Re: advice request - Pinion Oil Seal on 82 Scrambl

[ QUOTE ]
Are we making this to complicated? All the guy wants to do is change the pinion yoke seal. A smart guy, Pontiac59, once told me,"count the threads at the end of the pinion before you remove the nut, then match it after replacing the seal".

[/ QUOTE ]

Pretty sure that Pontiac will agree with the content of that old thread that I posted above too. Maybe just a matter of what tools and resources you have on hand.

One thing is for sure... You do not want to be running along at highway speed and have it come apart. Remember that we are talking about the rear axle. Makes a bit of a difference how you use it.

It's only a small fraction of a turn between loose and crushing the sleeve more, possibly over tightening the pinion on an AMC20. And you will need to put some serious ump'f on it to get where you need to be.

It's not complicated, just a bit tricky if I'm going to trust it at 60 or 70 MPH.

New pinion nut, locktite etc. suggested.

Trail only rig that never goes over 30 MPH... Maybe it doesn't matter since it won't kill you.

Some things are important if you want to grow old. /ubbthreads/images/graemlins/laugh.gif

Actually I didn't want to grow old, but it's getting a bit late to argue now. /ubbthreads/images/graemlins/tongue.gif

/ubbthreads/images/graemlins/40BEER.gif
Dale
 
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