Pinion Seal Replacement

[VKSheridan]

Hey gang! I think I accidentally “grass wrapped” the pinion seal on my rear axle. My rig is a 2020 Rubicon with stock OEM axles.

I’m going to replace the seal in my driveway. Any tips, tricks or task enhancement feedback worth sharing other than “Drop driveline, remove yoke, replace seal, fill, reassemble “?

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[grimmjeeper]

Don't over torque the pinion nut or you'll be replacing bearings soon.

 

[Some Random Guy]

I would count pinion shaft threads, then mark the nut and pinion shaft. Then get a “before” pinion torque-to-rotate with no tires on. If you’ve never done gear setup just know that it is very sensitive when you put that nut back on.

 

[chevymitchell]

Hey gang! I think I accidentally “grass wrapped” the pinion seal on my rear axle. My rig is a 2020 Rubicon with stock OEM axles.

I’m going to replace the seal in my driveway. Any tips, tricks or task enhancement feedback worth sharing other than “Drop driveline, remove yoke, replace seal, fill, reassemble “?

This is a 15 minute job, so don't over think it.

1. Remove Driveshaft.
2. Remove pinion nut.
3. Remove flange. (3 jaw puller works fantastic.)
4. Pry out old seal.
   1. Inspect old seal for seal spring. Make sure it's there on the old seal and laying behind the tail bearing.
5. Before installing new seal, apply a light bead of RTV around the seal. The RTV that comes out of the package on the new seal is like a wet fart. Don't trust it.
6. Install flange.
   1. This isn't a complicated effort. Just tighten it until there is no movement in the flange. Tighten, then wiggle the flange in every direction. Once there is no movement, stop. You're done with that. Don't count threads. This will not work here. Once the flange is against the sleeve, a 1/32 extra turn on the nut could be the difference between good and smoke checking the bearings. Again, tighten until there's no movement and then stop.
7. Install driveshaft.
8. Burnout.
9. Post pic here.

 

[VKSheridan]

Much thanks for the info. I’m still slumming and bumming on the backroads of Montana (watching my oil level of course and keeping the diff out of water) and will hop on this in a couple weeks provided the damn seal isn’t on a ten month backorder…..LOL

 

[chevymitchell]

Much thanks for the info. I’m still slumming and bumming on the backroads of Montana (watching my oil level of course and keeping the diff out of water) and will hop on this in a couple weeks provided the damn seal isn’t on a ten month backorder…..LOL

I’ve got a bunch of them here if you need one.

 

[J0E]

Hey gang! I think I accidentally “grass wrapped” the pinion seal on my rear axle. My rig is a 2020 Rubicon with stock OEM axles.

I’m going to replace the seal in my driveway. Any tips, tricks or task enhancement feedback worth sharing other than “Drop driveline, remove yoke, replace seal, fill, reassemble “?

Why do you think it's because of grass? Shouldn't that be covered under the powertrain warranty?

Both ChatGPT and Bard are skeptical grass is the problem.

 

[VKSheridan]

I went down a creek several months back that had a lot of river grass in it. When I got back to the load out area and did her “pre-highway” inspection, the underside looked like my Wrangler was wearing a hula skirt. There was weed wrap on the driveline, dangle wrap on the suspension and creek moss in the skids. I cleaned it up as best I could while I was there and then cleaned it more when I got home.

Fast forward and judging by what I pulled with a seal pick, it looks like I didn’t get it all out from behind the rock deflector. I pulled a few strands of what has the texture, grain and appearance of grass so that’s what has me leaning that way. After pick cleaning (which is not remotely thorough or a “fix”), the few oil drops stopped until recently.

I was planning on changing the seal regardless since cleaning doesn’t restore potentially etched sealing lips but figured I’d ping you guys as there’s always a “look for this” that experience creates and Chilton manuals don’t.

As for doing it under warranty, I fear the dealer would charge me ten times more than it’s worth while denying coverage to the seal because I changed the gas cap to a locking cap. The juice just isn’t worth the squeeze if ya know what I mean.

 

[VKSheridan]

Finally got back into town to proceed!

My yoke tested the legs of my puller (Step 3) but we prevailed. Everything went to plan and yes sir, I applied RTV to the seal flange because I agree, the orange strip isn’t all that impressive.

Putting the yoke back on though was Step 3 in reverse and I’m not confident in how I executed Step 6.

Putting the yoke on got real tight, real quick so I had to pull it on with the nut. I set my torque wrench to 130 figuring anything higher than that is crushing roller cages but to be honest, I’m not sure that was enough. It’s in the “General area” of where it was but thread counting ain’t my strong suit.

I pulled, wiggled and tried my damndest to see if there was any free movement indicative of a no-load situation but still, my gut was skeptical.

Unlike a free floating slip yoke where you seat the bearings and then rotate the nut a specified amount to get a desired preload or free-load, this configuration seems risky. How in the hell can you tell you’re loose or tight when the yoke to spline tension is also in the mix? Rhetorical question, keep reading….

As I was preparing for the recommended burn out I noticed when I lift my foot off the gas and the direction of torque flow reverses, I feel a growl.

No heat (yet) but a very noticeable growl (noise plus feel) when the torque goes from the diff to the engine.

On acceleration, no noise or growl, just when changing the direction of torque.

It’s there but less pronounced if I slow by slapping into neutral. I didn’t really notice anything in high speed reverse but that doesn’t change the sensations in forward.

It’s like the pinion is no longer properly seated with the ring gear and because of that, it’s not liking its new location and moving when it’s the drag instead of the tires. In English, I just described pinion float.

Question: If I run that bitch (the nut) in with an impact and then loosen the nut just a tick to relieve *some* of the crush, what are your thoughts? I don’t like having a growl that was never there before but I am not sure of any “driveway alternatives” other than hammer to ensure she’s tight and then loosen to let ‘er loosen.

Thoughts?

 

[VKSheridan]

UPDATE:

With the wheels off the ground and the transfer case in neutral, I put my impact on the pinion nut (the crowd gasps). I’ll bet I got another solid 4 turns of the nut.

Since torque is irrelevant because you’re pushing the yoke on tensioned splines and measuring flush yoke to race is equally out the window, there’s no accurate way that I can see to properly set preload other than “run it till the nut stops turning and nothing more”.

Driving it now - No heat, no noise, no grumbling.

 

[patreesheo]

Bought a 21 Rubicon a month ago. I was swapping the Rough Country suspension that came with it with a Clayton when I noticed the front drive shaft was replaced with a RC shaft. I figured it was a bonus and left it. However, I also noticed that the bottom of my differential is greasy. No other leaks apparent from the diesel engine above with 36.000 miles....

SO, thinking of changing my seal. Any thoughts why this could be happening due to the new driveshaft?

 

[chevymitchell]

Bought a 21 Rubicon a month ago. I was swapping the Rough Country suspension that came with it with a Clayton when I noticed the front drive shaft was replaced with a RC shaft. I figured it was a bonus and left it. However, I also noticed that the bottom of my differential is greasy. No other leaks apparent from the diesel engine above with 36.000 miles....

SO, thinking of changing my seal. Any thoughts why this could be happening due to the new driveshaft?

Likely wasn't due to the new shaft. It just happens. If the jeep didn't see 4wd much, then the seal could just be leaking from non-use.

 

[JEEP4U]

Likely wasn't due to the new shaft. It just happens. If the jeep didn't see 4wd much, then the seal could just be leaking from non-use.

Clean off the area with some brake clean and a rag. Check your differential fluid level...... Drive it and recheck for leaks.

 

[word302]

UPDATE:

With the wheels off the ground and the transfer case in neutral, I put my impact on the pinion nut (the crowd gasps). I’ll bet I got another solid 4 turns of the nut.

Since torque is irrelevant because you’re pushing the yoke on tensioned splines and measuring flush yoke to race is equally out the window, there’s no accurate way that I can see to properly set preload other than “run it till the nut stops turning and nothing more”.

Driving it now - No heat, no noise, no grumbling.

I'd expect your pinion tail bearing to fail in the next 6-12 months. These things are VERY sensitive to too much preload on the bearings and your impact (assuming it's a decent one) likely took you well beyond where you wanted to be. Hope I'm wrong. Good luck.

 

[VKSheridan]

We’re cruising past 6 months and 7,000 miles with no anomalies but I share your skepticism. I should have clarified I used the impact to get the additional 4 spins of the nut, not to hammer torque but like you implied, that’s not a good way to set preload. We’ll see what happens, I might get my regear sooner…..LOL

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