H3, CV or Differential Seal?

[Graham2990]

So upon the maiden voyage of my new Bendpak lift today, I noticed the following leak pictured below.

I'm torsion bar cranked to 23.5, but I remember reading here over the years about leaking CV joints in these trucks due to extreme CV angles....

I've never replaced a CV joint. Bought the truck at 72K, currently at 97K...

I'm not sure if that's what I'm dealing with, or if this is a seal issue on a separate component. If a differential seal is such a thing?

Is this something that can be solved by simply swapping in a new CV joint? Or is there some other differential seal I need to deal with?

This was on the drivers side FWIW. Second pic gives the best detail to location.

Bonus picture of the new lift.

 

[USMC_TOP]

Common leak spot. Nothing to do with your shaft angle


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[4speedfunk]

Yup...very common. $22 at GM. AAM sells both sides as a kit with seals and output bearings...
http://www.ebay.com/itm/like/152474...7290-0%26rvr_id%3D1185518206329&ul_noapp=true


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[alrock]

4speed, why is this anything more than just replacing the seals - do you think the bearings are necessary? Seals can also be found on Amazon. https://smile.amazon.com/gp/product/B001KSEGW4/ref=oh_aui_detailpage_o00_s01?ie=UTF8&psc=1

 

[4speedfunk]

No...most likely, the bearings are fine. You'll be able to inspect them once you get the old seals out. I would strongly recommend OEM seals (GM, Delco, or AAM), as opposed to aftermarket (National, Duralast, NAPA, etc.). I've heard stories of people installing aftermarket seals, only to re-do the entire job with OEM parts because of leaks. This might also be caused by worn output bearings (which might explain why AAM includes them). Regardless...this is one area where you want to use the OEM seal. It's too big of a job to save $5 on cheap seals.
You might consider doing both sides while you have it drained down. They almost always fail within 10k miles of each other.
Plan for an hour per side, unless your truck is exceptionally rusty. The only special tool might be a slide-hammer to pull the hubs off the knuckles (they are often fused with rust). You can usually rent one at your local parts store. Be careful re-installing the CVs into the new seals...they can be ripped.

 

[Graham2990]

I appreciate the information. So are there any special tools required for seal / bearing replacement?

Just skimmed through the manual on the Schwarttzy site and it's mentioning a few specialized GM tools.

What about stuff worth replacing while I've already got it apart? Anything else worth doing?

I think I'm just going to go ahead and order the bearings so I've got them if I need them.

These the ones?

https://smile.amazon.com/ACDelco-26...rd_wg=MUbWZ&psc=1&refRID=KAD24631KFA1QPJ4VX8B

Thanks!

 

[Reloader]

Just installed 4 off them thar seals this weekend. Two in my Alpha while regearing front diff and2 more in a 3T today while installing a set of Scorpworks side mounts.
If you look at one off the seals you will see that the actual rotating seal is internal and the part that the axle surface slides into is designed to grab the axle and turn with it. There is crosshatching to give it grip. What fails is that seal that grips the axle and then wears a groove into the metal seal surface on axle. When ever the dealer replaced one of these seals under warranty GM wanted them to replace axle also due to worn ring on sealing area. This is why reman axles are bad. Always go with new axle. The internal seal probably never hardly ever fails cause it's protected inside seal.
I always use GM oe ones as they cost me $14 at my dealer and $12 on Amazon if you can wait a couple days. When installing these seals its important not to drive them into bore with a hammer directly. If you ding up outer rubber coated part it can compromise the internal seal.
I use a square block of aluminum or an actual bearing race installer so pressure is applied equally all around seal. No sealant required on out side surface and I only apply grease to snap ring to center it on axle so it easily slides into end gear and clicks . Seal surface is dry to allow that inner ring to grip axle.
About them Torrington bearings in axle housing, on the left side if there is up and down axle movement you should be able to take some of that out by replacing both bearings. There is 2 on that side. One holds the cv axle stub and the other supports the coupler connecting stub to intermediate shaft. I believe the bearings there are 2 different sizes.
On the diff side if there is excessive up and down movement you can try replacing Torrington bearing BUT there may be excessive play in carrier/end gear connection. The end gear is harder than carrier so it's the carrier that needs replacing which means diff rebuild time.
Ive noticed that a little up and down movement is acceptable as I have installed seals on those and they seam to hold.
When you pull axle shaft inspect seal surface area after polishing up with some fine crocus clothe or a piece of the brown 3M pad. If grove is gone or mostly gone you should be ok. If you can catch a nail in grove , time for new axle.
if your 3 is an Alpha I highly recommend you pop for Genuine GM axles. The A-1 Cardon't selects are fine for the 5 bangers.
Sorry so long this was.

 

[alrock]

Agreed on the seals. Have only been buying AC Delco ones after hearing of others failing. Like you said, GM and AAM would of course work well.

 

[4speedfunk]

Also, it's a great time to install urethane bushings in the outboard diff mounts. You can unbolt them and do the work on a bench...much easier than trying to do it under the truck.


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