What are these rubber pieces on my 2007 tahoe rear diff fill plug?

[dpx2]

I have a road hum when I drive my 2007 Tahoe (rear end is a G80) so I thought I'd check the read diff fluid. When I pulled the fill plug, I found about five 1/2" rubber pieces that are about as thick as pencil lead, stuck with some grease/sludge on the fill plug. They are definitely flexible. Any idea what these could be from? I know the truck had a pinion seal replaced at 78k miles, long before I bought it. It now has 173k on it. I didn't drop the cover yet, but plan to.
Any idea what these pieces might have come off of?

 

[dpx2]

These are the pieces

 

[Blackcar]

If they used RTV on diff cover what squeezed to the inside may of broke loose.

 

[Fless]

Moved this to the 2007 section for you.

 

[dpx2]

Moved this to the 2007 section for you.

Sorry, I just noticed the sections are based on model years. Appreciate it !

 

[dpx2]

If they used RTV on diff cover what squeezed to the inside may of broke loose.

Possible, but they are so uniform, not like something squeezed out of a tube?

 

[gooffeyguy]

Looks like part of an o-ring. From where, I can't say. Does the fill plug use an o-ring, I can't remember?

 

[dpx2]

I didn't see an o-ring on the fill plug, so maybe that's it. The pieces don't look like they were ever round tho, straight as an arrow.

 

[Geotrash]

My money is on RTV. When it gets laid down in an even bead with a caulking gun like a shop uses and squeezed out between parts, it’s often in a perfect toothpick-like shape.

 

[dpx2]

I guess when I pull the cover I'll know if there's a gasket or rtv was used. I'm hoping gasket so I can re-use it. Otherwise I'll have to clean it up really good and use RTV to put it back on, which I've never done. And, it'll be in a cold garage - which I read you should only use RTV in temps 65 degrees or higher. That might be April before I can use it..lol..it's going to be only 25 degrees for a high for awhile here in Nebraska...

 

[Geotrash]

I guess when I pull the cover I'll know if there's a gasket or rtv was used. I'm hoping gasket so I can re-use it. Otherwise I'll have to clean it up really good and use RTV to put it back on, which I've never done. And, it'll be in a cold garage - which I read you should only use RTV in temps 65 degrees or higher. That might be April before I can use it..lol..it's going to be only 25 degrees for a high for awhile here in Nebraska...

Ah, Midwest winters! I don’t miss that when there’s work to do on the car.

Why not order a gasket from Rockauto to have on hand for the job just in case the one that’s there is trashed? My guess is that whoever pulled the diff just added RTV to the gasket to prevent a comeback (totally unnecessary). I’m 100% sure that the rear diff cover uses a gasket on your rig and not just RTV.

 

[dpx2]

I could do that too! I think I'll follow that suggestion, thx!

 

[Rocket Man]

I guess when I pull the cover I'll know if there's a gasket or rtv was used. I'm hoping gasket so I can re-use it. Otherwise I'll have to clean it up really good and use RTV to put it back on, which I've never done. And, it'll be in a cold garage - which I read you should only use RTV in temps 65 degrees or higher. That might be April before I can use it..lol..it's going to be only 25 degrees for a high for awhile here in Nebraska...

I wouldn’t use RTV to seal the rear cover with, you’ll get the same result with RTV inside the cavity. LubeLocker makes an awesome gasket for the G80 that is reusable. Guaranteed to never leak and it’s easy to install.
Part # is LLR-G850.