How to replace a pinion seal on your TJ

TJDave

TJ Enthusiast
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Oct 27, 2015
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San Jose, CA, United States
My rig has 119.5k miles on it. The overwhelming majority are highway miles, but, it's seen its fair share of off road miles, too. Recently, while doing a grease job under it I noticed the front pinion seal was starting to leak. Well, at 119.5k that old seal deserved to be retired so I set forth to set it free...

Let me correct that. I've never done this procedure and so I sought out the help of someone who had, Bill M; 87YjBill. I took the following pictures and asked a boatload of stupid questions as Bill patiently responded, and allowed me to take photo's at each step. Thanks a million Bill! Here we go...

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Removing the yoke strap bolts to drop the axle end of the front drive shaft. NOTE; That impact wrench is 950lbs.


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Dropped the axle end of the front drive shaft.


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With a punch, Bill marked the relationship between the pinion shaft and the pinion nut so that at reassembly it could go back together exactly the same way, so as to not change the pre-load.


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Pinion nut removed with a good impact gun. Sorry, I forgot to note the socket size...for that matter, I didn't document any of the tools/sockets etc. I was to busy asking stupid questions and trying to get enough light to shoot the pics......


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Removing the yoke required a few strategically placed blows...


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The leaky seal.


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Bill starts with a chisel to peel back an edge of the seal.


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Here's the seal partly "peeled" back.


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Next he gets a "Seal Puller" and prys the old seal the rest of the way out. With a little work, it comes out. I should mention that while doing this, Bill whacked the bejeebers out of his funny bone on the passenger LCA bolt...that was probably worth $10.00... :)


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Now he cleans up the yoke with a wire brush.


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Here's the new pinion seal which I got here:
https://www.amazon.com/dp/B00HHGHW42/?tag=wranglerorg-20



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Carefully tapping in the new seal to seat it.


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Time to put it all back together! Installing the yoke...


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The pinion nut re-installation. Bill uses an impact gun to get it as close to lining up as possible. Removes the gun/socket and checks to see how close it is. He goes through this a few times before he gets it EXACTLY where it was when we started...


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All that was left was to install the drive shaft and go for a test drive!

It went very smooth. No surprises. The cost of the pinion seal from Amazon was $6.99. Bills labor was $50.00. While we were under there we decided it was a good time to drill that top hole in the rear track bar relocation bracket and cinch it up. And...while we were poking around under there Bill noticed my passenger side M.O.R.E. 1" Bombproof (Rubber) motor mount never got completely bolted up/cinched. Seems when I installed them two years ago I forgot to finish bolting it up...what can I say? A rookie mistake! But, now it got caught and corrected! Oh, add another $30 to the bill for my screw-ups...
 
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The I replaced my pinion seal I just torqued it down to the proper spec (the nut) and that was it. Was that a mistake?

I never had any issues with it (this was on my old XJ by the way) after that point.
 
I did the "mark my nut" method and it worked fine.

That pinion seal looks different than the ones I've replaced on dana 30's.
 
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For those who have the tools and want to set the pinion pre-load properly, you need;

250lb torque wrench although you can make do with a breaker bar if you're careful.
1-1/8" socket to fit the torque wrench/breaker bar.
An accurate dial-type inch-pound torque wrench (and probably socket drive adapters to fit the big 1-1/8 socket)

Understand that any torque setting means absolutely sweet FA. It's just a starting point, especially if you've replaced the crush-sleeve - which is not usually necessary. With the driveshaft, wheels, and drums removed, you use the inch-lb torque wrench to see how much rotational force is required to rotate the pinion shaft BEFORE you do your final tightening. You would do this while you still feel slight play in and out, like after you've changed the seal, installed the yoke/nut, and taken most of the slack out.

For instance, I measured mine at 9 in-lbs. The Dana 35 is pretty puny so it doesn't take much to turn it.

You now incrementally tighten the nut 5 - 10 ft-lbs and keep checking with the in-lb wrench looking for a 5 in-lb increase in rotational force. This is the only accurate way to know that you've compressed the crush sleeve enough to put the correct preload on the pinion bearings. It doesn't take much rotation to overdo it. Back it off if you've gone too far. If you exceed 300 or so ft-lbs - need new crush sleeve. I used a big pipe-wrench to brace the yoke while tightening the pinion nut.

In my case, the seal wasn't leaking. Just wanted to take the play out after 130,000mi. I wound up turning the nut 30-50 degrees to achieve this.
 
Getting ready to tackle both front and rear - both are leaking. Love the double bonus round! I have all the tools, just not sure of the talent! Also going to install a poison spyder bomb proof cover while I am it since I have to tear it all apart anyway. Called around to a couple of local shops to see how much they would charge and it was $600-$700. I can buy a lot of other cool parts for that, so here it goes!!! Thanks for the write up - really helpful. Several good youtube videos out there as well.
 
Getting ready to tackle both front and rear - both are leaking. Love the double bonus round! I have all the tools, just not sure of the talent! Also going to install a poison spyder bomb proof cover while I am it since I have to tear it all apart anyway. Called around to a couple of local shops to see how much they would charge and it was $600-$700. I can buy a lot of other cool parts for that, so here it goes!!! Thanks for the write up - really helpful. Several good youtube videos out there as well.

please let us know how it went and what you did and post some pictures. thanks! will tackle this job soon as well
 
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This is an old thread, but it might just be what I need. I replaced my pinion seal on the front diff just a few weeks ago, and I tightened the nut to match my marks exactly. However, within a few days I started getting a sound during acceleration that seems to be coming from the pinion. I did not want to mess with any preload issues, but I might have to.

@RaymondT posted an excellent explanation of the method for setting that preload, but I am confused about where to begin. How do I know if the crush sleeve needs replacing, and what am I disconnecting prior to starting the process that he described?
 
I'll be doing this Tuesday on both my front and rear dana 44s. I'm going to use the "mark my nut" method and count the exposed threads to double ensure it goes back on correctly. Just to verify replacing the gasket is the same method for front and back? Also if i happen to overtighten/undertighten the pinion nut whats the worst case scenario?
 
I just replaced mine both and front rear and realized it did not come with the “outer” part of the seal. (I’m not sure what it’s called but the part that makes it look flush.) I took before and after pictures and that’s really when I noticed it. Is that normal for a 2005 LJR?

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I just replaced mine both and front rear and realized it did not come with the “outer” part of the seal. (I’m not sure what it’s called but the part that makes it look flush.) I took before and after pictures and that’s really when I noticed it. Is that normal for a 2005 LJR?

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The "flush seal" is Dana Spicer 50531

I installed the same pinion seal you did prior to heading to Moab a few weeks back and have not had any issues. My jeep has rubicon axles front and rear. I'm not concerned with running without the dust cover. Actually, in my case I swapped the yokes to match my driveshafts (1310). When I did that the yokes made a grinding noise on the dust cover so the fix was to remove it.
 
I've read a lot of conflicting information in my research on replacing both Dana 30 and Dana 35 seals.

Some forum goer's (on Jeep Forum, Wrangler Forum, etc.) strictly advise using a new crush sleeve, new pinion nut, and using an inch/pounds dial to measure the rotating torque of the pinion nut to correctly crush the new crush sleeve and correctly torque on the new pinion nut.

Other forum goer's state that marking the location of your pinion nut first either by indexing, or with a paint pen, and re-using the pinion nut with some blue thread locker, and torquing the pinion nut to the exact same spot that it was before is completely fine. I read a post by Jerry saying that performing this method was usually completely fine - like anyone I trust Jerry's word over anyone else's. However, i'm still hesitant.

I was planning on:
  1. (first draining all my differential fluid)
  2. Measuring and recording how far down the pinion gear shaft my pinion nuts are (on both my differentials)
  3. Marking them with a paint pen
  4. Removing the pinion nut
  5. Removing the yoke with a gear puller
  6. Replacing the pinion seals (with some Permatex black silicone)
  7. Re-install the same pinion nuts (with some blue loctite) by torquing them only until they reach EXACTLY where they were before
What are ya'll's thoughts and experiences with this?
 
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I've read a lot of conflicting information in my research on replacing both Dana 30 and Dana 35 seals.

Some forum goer's (on Jeep Forum, Wrangler Forum, etc.) strictly advise using a new crush sleeve, new pinion nut, and using an inch/pounds dial to measure the rotating torque of the pinion nut to correctly crush the new crush sleeve and correctly torque on the new pinion nut.

Other forum goer's state that marking the location of your pinion nut first either by indexing for with a paint pen, and re-using the pinion nut with some blue thread locker, and torquing the pinion nut to the exact same spot that it was before is completely fine. I read a post by Jerry saying that performing this method was usually completely fine - like anyone I trust Jerry's word over anyone else's - however i'm still hesitant to try this method.

I wanted to see what those on this forum had to say?

Thanks!
On my old dana 35 I used the paint marker method and it was fine. Given I do not put many miles on my TJ. If its used as a daily driver I would be inclined to do it the proper way. @bobthetj03 has done it the inch/pound way so he could probably help you with any questions.
 
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I've read a lot of conflicting information in my research on replacing both Dana 30 and Dana 35 seals.

Some forum goer's (on Jeep Forum, Wrangler Forum, etc.) strictly advise using a new crush sleeve, new pinion nut, and using an inch/pounds dial to measure the rotating torque of the pinion nut to correctly crush the new crush sleeve and correctly torque on the new pinion nut.

Other forum goer's state that marking the location of your pinion nut first either by indexing, or with a paint pen, and re-using the pinion nut with some blue thread locker, and torquing the pinion nut to the exact same spot that it was before is completely fine. I read a post by Jerry saying that performing this method was usually completely fine - like anyone I trust Jerry's word over anyone else's. However, i'm still hesitant.

I was planning on:
  1. (first draining all my differential fluid)
  2. Measuring and recording how far down the pinion gear shaft my pinion nuts are (on both my differentials)
  3. Marking them with a paint pen
  4. Removing the pinion nut
  5. Removing the yoke with a gear puller
  6. Replacing the pinion seals (with some Permatex black silicone)
  7. Re-install the same pinion nuts (with some blue loctite) by torquing them only until they reach EXACTLY where they were before
What are ya'll's thoughts and experiences with this?

I replaced my rear pinion seal on Dana 44 I just swapped into my 2000 TJ. I used a new SKF Pinion Seal and a new Spicer nut. Pulled old seal with a puller, cleaned it up and hit brought spots with Emory cloth, then installed the new seal and nut and torqued to 180 ft lbs. No leaks. No issues. It’s a self locking nut, so you are better off spending the $6 and torquing to factory specs. My $0.02...


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I thought that the Dana 30 and Dana 35 pinion seals were the same. So I installed a Dana 35 pinion seal on my Dana 30, and just realized that the inner diameter of the seal doesn't even meet the yoke.

I'm pretty positive this is not how it's supposed to look like:

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After more research, it appears that the Dana 35's pinion seal is different than the Dana 30's?
 
I'm having a devil of a time getting the new pinion seal back into the Dana 30 front diff. I am actually on my second seal. I was only able to get the first one (O'Reiley's) about 1/2 in and I could nto get it to seat further, I was afraid to force it. Upon removing I bent it up.

Off to Napa a went to get another seal, and now I'm afraid to try to get it to seat. Did you all grease it up or use RTV. The new one seems to have a substantial bead of sealer on it and I'm wondering if some grease might get it in easier.
How hard was it to get your to seat?

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