Leaking oil near the rear differential

Whitelightning

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Noticed some oil leaking, thought it was from the differential cover, (which I’ll service anyway cause I’m sure it’s been a while).

I guess this is a seal in there. I’ll try and find a YouTube video, I’ve replaced u joints on a driveshaft once, so I have an idea how to get it off to get to that seal.

Also, I just replaced the manual transmission fluid… would this have anything to do with overfilling?

There’s about to be another hurricane coming through, so I might not have a chance to fix this for a bit.

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Its a crush sleeve diff. Those can turn into more than you bargain for.

I have a decent variety of tools, and the local parts stores have a bunch of specialty "loaner tools" that I utilize pretty often.

What would be the main thing/step I should try not to screw up to not turn the small fix into a big one ? 😅

Also, I'm seeing in some videos that people recommend using RTV on the seal. In the FSM, I see it says to use gear oil.
 
Good point, I've only attempted this on my front Dana 30. What's the tricky part for a crush sleeve diff?

On a solid spacer pinion you take off the yoke,pry out the seal and do the reverse to be done. Guys with crush sleeve diffs can get in trouble being lazy trying to copy that.some get lucky,some don't.there are some hokus pocus ways but if you don't measure preload you don't know.

The trouble lies in the sleeve setting preload and the risk of changing that when torquing the nut. To do it right you pull the axles and carrier,get a dial type inch pound torque wrench,and make sure of the preload while torquing.
Like Mac said,some of them refuse to crush at first.it is easy to go past the proper torque and need a new one.
 
On a solid spacer pinion you take off the yoke,pry out the seal and do the reverse to be done. Guys with crush sleeve diffs can get in trouble being lazy trying to copy that.some get lucky,some don't.there are some hokus pocus ways but if you don't measure preload you don't know.

The trouble lies in the sleeve setting preload and the risk of changing that when torquing the nut. To do it right you pull the axles and carrier,get a dial type inch pound torque wrench,and make sure of the preload while torquing.
Like Mac said,some of them refuse to crush at first.it is easy to go past the proper torque and need a new one.

Thanks for the replies everyone.

I've been reading the FSM, doing a little research. I still need to do a little more studying...

Also, I happened to stumble across some "crush sleeve eliminator" videos on Youtube... gonna check it out now to see what thats about.
 
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To do it right you pull the axles and carrier,get a dial type inch pound torque wrench,and make sure of the preload while torquing.
Like Mac said,some of them refuse to crush at first.it is easy to go past the proper torque and need a new one.


I haven't found any "idiot-proof" ways to do the crush spacer or the solid spacer (crush eliminator) alternative. The dial-type torque wrenches aren't cheap either. (I do have access to a lift though). @Rickyd in the 2003 FSM I don't know if it mentions pulling the axle and carrier. It just says :

(10) Remove pinion shaft seal with a pry tool or a
slide hammer mounted screw.

(11) Remove front pinion bearing using a pair of pick tools to pull the bearing straight off the pinion gear shaft.

(12) Remove the collapsible spacer.

Because the crush spacers are cheap, can't I just buy a few and repeat if I over-crush it?

Also, I've read that the crush spacer is only used from the factory to save on production costs and a solid one is superior, is that true?

I'm fine with whatever option as long as it's done properly so I don't break something expensive
 
You need to be able to measure the pinion preload. That can only be done with the carrier and axles out

This is true , but I have had success marking the nut , counting the turns to remove it , replace the seal reinstall the yoke and tighten the nut with the same turn count and a TINY amount more. No issues with the 3-4 rear diffs. I reused the sleeve with. Is it right No , maybe I was just blessed when I was dirt poor....:LOL:
 
You need to be able to measure the pinion preload. That can only be done with the carrier and axles out
Will I still need to use a dial torque wrench if I put in the crush eliminator (with the axle pulled). I’m thinking it’s probably no benefit of doing the crush spacer if I have the axle and carrier out right?

what’s your opinion? Also, I watched a video where this guy was talking about moving the carrier closer/further to the pinion and a few other confusing stuff… just hard to understand what someone’s talking about, never messing in an axle before
 
If your gonna install new bearings then by all means pull the axles and carrier and buy a bearing kit. However, there is no need to replace the crush sleeve for a pinion seal R&R. If there is play in the pinion shaft, the pinion bearings are scored/worn etc, then the races are bad as well and that opens another can of repairs. You will not crush the sleeve further with a 1/2" rachet and new pinion nut or using 271 on the old one if necessary. As other have mentioned, stake the existing pinion end, the nut to match, and you'll know exactly where it was when you reinstall the nut and tighten it back up. A new seal will not change diddly as far as preload.
 
Will I still need to use a dial torque wrench if I put in the crush eliminator (with the axle pulled). I’m thinking it’s probably no benefit of doing the crush spacer if I have the axle and carrier out right?

what’s your opinion? Also, I watched a video where this guy was talking about moving the carrier closer/further to the pinion and a few other confusing stuff… just hard to understand what someone’s talking about, never messing in an axle before

You need the dial indicator to set up the eliminator to start.
This is true , but I have had success marking the nut , counting the turns to remove it , replace the seal reinstall the yoke and tighten the nut with the same turn count and a TINY amount more. No issues with the 3-4 rear diffs. I reused the sleeve with. Is it right No , maybe I was just blessed when I was dirt poor....:LOL:

You have a lot of experience and skill. It just isn't something I'd recommend for a beginner. I bet you can spin the yoke by hand and know if it's loose or tight. It's a good idea to learn to do something right before you try and cheat.
 
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This is true , but I have had success marking the nut , counting the turns to remove it , replace the seal reinstall the yoke and tighten the nut with the same turn count and a TINY amount more. No issues with the 3-4 rear diffs. I reused the sleeve with. Is it right No , maybe I was just blessed when I was dirt poor....:LOL:

I've done this method countless times. No issues. Yes, everything you're suggesting is technically correct...but most of us shade tree mechanics have slapped a new seal in and go.

Heck Rick Pewe and David Frieburger just did it in this video...


-Mac
 
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