C.V. Axle Seal Part Question

[FlyFish3rman]

Hi All,

I have an 07 4.2 trailblazer with 4WD. I want to replace the outer most seal on the driver side of my front differential. The one that the CV shaft is inserted into. I'm replacing a bad CV shaft and I figured that I'd replace the seal while everything is out. It is not leaking currently.

I've searched the forum and people are saying the GM part number should be 19257296. The seal has the locking tabs on the inner side of the the seal.

I went to my local Chevy dealer, and the manager looked at the GM diagram and the diagram stated the correct seal should be 12479302 (which equates to part number 3 on the diagram). That seal does not have the tabs on the inner-side but a flat metal surface. I was also curious about the non-numbered part that seems to be before part (3).



Can anyone help before I tear everything down?

Thanks!

 

[TollKeeper]

Edit: Ignore this post, read below!

I think you might be better off in replacing the whole CV Axle Disconnect rather than just that seal.

 

[Matt]

I think you might be better off in replacing the whole CV Axle Disconnect rather than just that seal.

Wrong side Toll. He's wants the drivers side, not the passengers side.

@FlyFish3rman If you want the drivers side, you need the 19257296 part number.

 

[TollKeeper]

Ahh.. My bad...

So there are 2 iterations of this part. The earlier iteration has the teeth that you are referring to, and the later models dont. I talked to @Mooseman about this in the thread about my rebuild. It appears they are the same, but I dont have proof of this.

This is the one I put in my 2004 Envoy

https://www.amazon.com/dp/B0792JCVFM/?tag=gmtnation-20

The other part number you have listed above is the one for a disconnect (not sure of the vehicle).. Which is why I was confused.

Im also pretty sure the picture used above is not the one for the GMT360. You are after part #38 on the diagram below.

Best pricing I had found for this part, and immediate availability, was the dealer.... Surprisingly!

 

[FlyFish3rman]

Thank you all! You've confirmed my suspicion. We'll see if the dealer I bought the wrong part from will not charge the re-stocking fee for their mistake 🤞.

 

[Mooseman]

Yep, 19257296 is the correct one for the left side outer diff axle seal.

I'll say it again, dealers are idiots!

 

[FlyFish3rman]

Replaced the outer seal with 19257296 (from a different dealer who had stock) and the C.V. Axle. Popping noise while turning has gone away, but (as best as I can describe) a rhythmic humming/pulse remains while moving forward or reverse. I'm going to further investigate tomorrow and (possibly) start a new thread if I cannot figure it out.

Y'all are awesome, thanks!

 

[TollKeeper]

This Rhythmic humming could be a U-Joint, or even a Differential Bearing, or a wheel bearing, and less likely, but a possibility, a Transfer Case Bearing.

Knowing how this line eats wheel bearings, thats where I would be looking.
Does it change with speed?
Does it change when cornering?

 

[FlyFish3rman]

This Rhythmic humming could be a U-Joint, or even a Differential Bearing, or a wheel bearing, and less likely, but a possibility, a Transfer Case Bearing.

Knowing how this line eats wheel bearings, thats where I would be looking.
Does it change with speed?
Does it change when cornering?

The noise does change with speed. It sounds like it is coming from the front of the vehicle. I replaced both front wheel hubs a little less than a year ago due to ABS issues, but I wouldn't be surprised if one has failed again.

One thing that I haven't checked in the year since I've owned the TB has been the t-case fluid. I need to replace and re-fill that this week too.

 

[Mooseman]

It could have failed again if it was a cheap one.

 

[FlyFish3rman]

It could have failed again if it was a cheap one.

I did buy the duralast cheapies, but they're still under warranty so it could be worse. I'll check it out today after work.

 

[FlyFish3rman]

I've isolated the noise to the driver front area. When spinning the driver front wheel free hand it sounds like it is humming with a rhythmic click. I also spun the passenger front wheel and it is quiet.

I removed the hub assembly. It spins and there is no wobble but there is a very very feint grinding noise. The assembly is under warranty so I'm just going to pick up another. However, that is not the sound I'm hearing while driving.

I supported the spindle end of the CV Axle with one hand and spun it with my other. You can hear the clicking noise which sounds like it is coming from the diff. I just replaced the CV shaft and seal a couple days ago and visually inspected the bearing. It looked fine to me, but now I'm guessing that the bearings in the adjuster may be bad. The oil I drained had to of been close to the original, as it was midnight black.

Can I R&R the Bearing Adjuster without removing the diff? I looked through other threads and it wasn't stated explicitly, but it seems as though it is recommended it is replaced once removed. I've never repaired a diff before so this is new territory for me.

 

[Mooseman]

Haven't heard of anyone doing that specifically although there may have been one who re-tightened the adjuster that had worked its way loose. Most often when there is an internal problem with the diff, it's replaced as a unit with another used one. Just replacing the bearing and adjuster may require adjusting the whole diff for backlash as the ring gear position and bearing preload may be changed.

Did find this old thread about it.

Front Left Differential Seal and Adjuster Confusing Issue

Hello everyone, I have read many posts on here and the OS concerning the front drivers differential seal and bearing (adjuster). But I have yet to find anything posted asking the how and why (if you will) of putting the seal and adjuster back in the differential. I'll explain in a minute. To...

gmtnation.com

And this one is even more extensive:

NEED HELP - Replacing LH bearing in front diff, have questions.

Was surprised to find a loose roller bearing behind the LH CV axle seal. Looks like I can simply unscrew the adjuster but is there a procedure for this, special tool needed? Any surprises lurking? I can get the bearing buy never had to replace one. I was able to locate the loose rollers.

gmtnation.com

But apparently it can be done.

 

[FlyFish3rman]

@Mooseman: Thank you for the reply. I found those two threads, but I guess I have to read through them in finer detail. At this point, if it is the front diff, I'll just disable 4wd and join the 2wd club. I guess the way to find out would be remove driver side half shaft, fill seal with Gatorade cap, and take it for a test drive.

I did replace the wheel bearing and that didn't fix the problem. The only other thing I can think of it possibly being is a bad u-joint or even t-case bearing, but the sound and vibration appears to be coming from right below the gas pedal (having me think it is the front diff).

I took a video (not the greatest quality). What do y'all think?

 

[Mooseman]

Can't really tell from the sound clip. If you were in 2WD, then only the spider gears inside would be spinning so it wouldn't be a U-joint or the TCase. I'd pull the shafts, Gatorade cap the holes and see if the noise goes away.

 

[FlyFish3rman]

@Mooseman: Yea, I think that is what I need to do. Pull the shafts and see what happens.

My comment about the t-case and u-joints were in regards to the rear driveshaft. I was wondering if a bad rear u-joint or bad t-case bearing could cause the vibration and noise I'm describing, and if the vibration could travel up the drivetrain and make me "think" it is coming from the front diff.

Either way I'm going to pull the shafts and narrow this down. Thanks for all your advice!

 

[FlyFish3rman]

Officially apart of the 2wd club now. 2 CV shafts are out and plugged the holes with Gatorade caps. Removed the front driveshaft as well. No more noise!

The driver side bearing adjuster was shot due to very low oil for who knows how long. I may pull it and rebuild it at some point, but for now I'm on the road.

Next on the list is SAIS delete and a good tune. Thanks for all the help!