2011 GMC Yukon XL Rear End

[thewrightman]

Make

GMC

Model

Yukon XL

Year

2011

Miles

242333

Engine

5.3

Please see the attached video. I want to know what those little dodads are in the differential and what they do and do they wear out???? can/should they be taken out??? They look to me like a catastrophic failure waiting to happen.

 

[billr]

I think those are part of the limited-slip ("posi-traction") mechanism. Are you having some kind of problem with this diff? The parts you are fingering probably don't wear, but push on clutch plates that do. However, the clutches are in use so little, with most driving, that they tend to last "forever".

I guess that is more properly called a "locking diff", maybe this Eaton product?

https://www.eaton.com/content/dam/eaton/products/differentials-traction-control/mlocker/eaton-mlocker-brochure-2009-en.pdf

 

[thewrightman]

Could be. It's not like any locking differential I've worked on before. I was hoping someone had worked on one like this before and could give me the 101 class. The shutter I'm getting is when the vehicle is cold and on a straight of way. Originally I thought it was the transmission (242k miles) but it doesn't seem to have anything to do with transmission shift points and it goes away such that you don't notice after the vehicle gets warm - which doesn't sound like the transmission to me - sounds opposite.

 

[thewrightman]

I think those are part of the limited-slip ("posi-traction") mechanism. Are you having some kind of problem with this diff? The parts you are fingering probably don't wear, but push on clutch plates that do. However, the clutches are in use so little, with most driving, that they tend to last "forever".

I guess that is more properly called a "locking diff", maybe this Eaton product?

https://www.eaton.com/content/dam/eaton/products/differentials-traction-control/mlocker/eaton-mlocker-brochure-2009-en.pdf

Thanks, I'm reading the attachment/link now...

 

[thewrightman]

Thanks, I'm reading the attachment/link now...

That article plus driving it would seem to indicate to me that mine is working like it's supposed to. It's doubtful that's my problem. Thanks again.
PS: The universal joints seem to be fine. I'm going to change the transmission fluid tomorrow. I'll get back to you as I progress...

 

[EricC]

Those items are the differential governor and latching bracket. Basically when the left and right wheel speeds vary by +100 RPMs the counterweights fling out and cause the differential to lock so both sides are turning equally. As for causes of launch shudder...The center support bearing, driveline angles and transmission internals are all potential causes. Since yours seems to be temperature related I'd probably shift my focus to the transmission. Internal transmission seals tend to swell a bit as they warm up, and cold issues are often one of the first symptoms.

 

[grcauto]

What exactly is your problem and can you record it?

 

[thewrightman]

Update: Changing the differential gear lube DID make a difference. I'm hopeful now that it is not the transmission.

BTW, I should have told that it had over 230k miles on it when I got it.

What exactly is your problem and can you record it?

Please see my update...