Diff seal question

[ACR_GABOON]

I appears as though the drivers side output shaft seal is leaking on my car. I searched the internet for an exploded view of the diff and the one I found (for a 2005-2006 model) seems to show that the seal can be replaced without dropping the diff out of the car. Mine is a MY'2000 so I don't know if the diffs are the same or not. Can anyone shed some light on this for me? I'd rather not drop the diff if I don't have to. Thanks. Link to exploded view I found.............https://www.moparfactoryparts.com/oem-parts/mopar-differential-case-5161963aa?origin=pla&gclid=EAIaIQobChMInPL59pKd_QIV8MzICh3bnAd3EAQYASAB EgJMvvD_BwE

[GTS Dean]

I think the only external seal you can change without dropping the 3rd member is on the input pinion. To get to the output yoke seals, you have to pull the C-clips in the heart of the diff to remove the stub shafts.

[Steve M]

At the very least, you have to remove the axle and the output stub to get to it. If the stubs are retained by c-clips as GTS Dean indicated, you'll be dropping the entire thing so you can pop the cover off to access what's need to get those out. If they are circlips like they use on the later Gens, you might be able to get them out, but it won't be fun since there isn't much room to work.

As much as it sucks to hear, you should drop the differential to do the job properly regardless of whether or not you can remove the output stub in question with the housing still in the car.

FYSA, you'd also have to drop the differential to properly replace the pinion yoke seal on the front too. The crush sleeve that sets the pinion bearing preload is a one-time use item - if you loosen the pinion nut (and you have to do that to get to that seal), you must replace the crush sleeve. I'm sure there are some backwoods MF'ers out there that have reused crush sleeves, but it isn't worth the risk.

Edit: the last part isn't correct - my apologies.

[Old School]

FYSA, you'd also have to drop the differential to properly replace the pinion yoke seal on the front too. The crush sleeve that sets the pinion bearing preload is a one-time use item - if you loosen the pinion nut (and you have to do that to get to that seal), you must replace the crush sleeve. I'm sure there are some backwoods MF'ers out there that have reused crush sleeves, but it isn't worth the risk.

Actually, there is a procedure for doing this in Chrysler factory service manuals (don't know about Viper). You basically measure the pinion turning preload before disassembly (including the differential), then reassemble using this torque as the target. It's worked for me several times.

[Steve M]

Actually, there is a procedure for doing this in Chrysler factory service manuals (don't know about Viper). You basically measure the pinion turning preload before disassembly (including the differential), then reassemble using this torque as the target. It's worked for me several times.

You are correct - I was mistaken.

This is what I was basing my statement on (from the service manual I have):


Never loosen pinion gear nut to decrease pinion bearing preload torque and never exceed specified preload torque. If preload torque is exceeded a new collapsible spacer must be installed.

But I was reading into it too far. You can loosen the pinion gear nut, you just can't do it to decrease the preload due to overtightening.

For seal replacement, this is what they list as the procedure:

Removal
1. Mark pinion yoke and axle shaft for reference.
2. Remove propeller shaft from the pinion yoke.
3. Remove half shafts from axle.
4. Rotate pinion gear three or four times.
5. Measure and record pinion torque to rotate with an inch pound torque wrench.
6. Hold pinion yoke with Wrench 6719A and remove pinion nut and washer.
7. Mark pinion yoke and gear for installation alignment reference.
8. Remove pinion yoke with Puller C-452.
9. Remove pinion seal with seal puller.

Installation
1. Apply a light coating of gear lubricant on the lip of pinion seal and install seal with Installer 8889.
2. Install pinion yoke on pinion gear with reference marks aligned.
3. Install pinion yoke with Installer C-3718.
4. Install a new nut on the pinion gear and tighten nut only enough to remove the shaft end play.
5. Measure pinion torque to rotating with an inch pound torque wrench. Torque to rotating is reading recorded during removal, plus an additional 0.56 N.m (5 in. lbs.).
6. If rotating torque is low, hold pinion yoke with Holder 6719A and tighten the pinion shaft nut in 6.8 N.m (5 ft. lbs.) increments until torque to rotating is achieved.

CAUTION: If 393 N.m (290 ft. lbs.) maximum torque is reached prior to reaching the required rotating torque, the collapsible spacer may have been damaged. Replace the collapsible spacer.

By my read, as long as you are able to get to the initial preload reading +5 in-lbs without exceeding 290 ft-lbs on the pinion nut, you can reuse the crush sleeve/collapsible spacer.

Thanks for pointing that out...learned something new today.

[Dan Cragin]

If the rear end fluid has been overfilled or the fluid has been been overheated, those seals will leak.

First, I always change the fluid and clean the seal areas with simple green (not brake cleaner). 9 times out of 10 the leak goes away.

[ACR_GABOON]

If the rear end fluid has been overfilled or the fluid has been been overheated, those seals will leak.

First, I always change the fluid and clean the seal areas with simple green (not brake cleaner). 9 times out of 10 the leak goes away.

This is interesting. Anyone else tried this method with any success? Its worth trying but I am not getting my hopes up.

[dave6666]

If DC says something works 9 out of 10 times and you are still skeptical, but you'd trust someone else instead? lol

[Dan Cragin]

The seal could very well be bad, but I've always tried that course of action first. Make sure you don't overfill the rear end. The fluid level should be just below the fill hole.

[ACR_GABOON]

If DC says something works 9 out of 10 times and you are still skeptical, but you'd trust someone else instead? lol

Not sure what the point of your comment is, or who the "someone else" is that you are referring to that I'd trust. I meant no disrespect to Dan and unless I am misinterpreting what Dan is saying, I've personally never witness a seal stop leaking because the outside of it was cleaned. Seals leak because of damage, or debris being lodged between the seal and its mating surface. Believe me, I am all for not dropping the third member if I don't have to but cleaning the outside of a seal to correct a leak defies logic in my mind. Maybe someone can provide an explanation as to why this would stop the leak, I am all ears.

[Dan Cragin]

If the fluid is over filled, then the lubricant is above the seal and it can weep. If the rear end fluid becomes overheated (like at the track or very hard use) the seal gets superheated and the rubber becomes soft, allowing fluid to pass by it. Once the seal cools down, it hardens back up.

Just my experience and yours may differ, hope this helps. It will be good to see what the final resolution is.