01 Denali Transfer case problems

[Ventura139]

Sup all. Need some help/input on my ride. I have a 2001 GMC Yukon Denali 6.0 (not XL) with under 200k miles. I seem to be having issues with my transfer case. The truck is always in AWD so there is no switching between 2 or 4. And when ever the outside temp is close to 90 or my trans temp reaches 200 my AWD acts up. When ever I slow down around 5 to 10mph or when I am pulling into my driveway or a parking spot my front wheels seem to bind like the Tcase isn’t compensating for the slower speed. Has anyone experienced this before? It’s hard for me to get a mechanic to diagnose it because it doesn’t always show symptoms right away. You have to drive it until the fluid heats up.
Thanks for the input cause it’s aggravating since I just want to get it fixed already

 

[ks03]

I know I might be taking the symptoms the wrong way, and be way off… but I think this could be caused by wheel speed sensors dropping signal. On non AWD vehicles people will get unwanted abs activation at low speed, but if you have AWD it can act like traction control working as hard as it can to keep you from moving.
I’d test the theory by disabling the ABS temporarily by pulling the fuse. If that eliminates the symptoms one of the front wheel speed sensors would be my top suspect. Check for play in the bearings, if they’re good, I’d try cleaning rust out from under the sensors… this brings us back around to the cause of wss issues and why it may act up when you’re seeing it. The rust under the sensor increases the air gap between the sensor and the reluctor wheel, which causes it to drop out at low speed. When the wheel hub assembly is at its hottest I suspect it could expand, increasing the air gap with it

 

[S33k3r]

The other problem you may experiencing is a pinhole leak in the transfer case. Until it gets hot, you have enough oil... But I am just guessing.

 

[afpj]

When was last time transfer case and front differential fluid changed? Any pending codes?

 

[Ventura139]

When was last time transfer case and front differential fluid changed? Any pending codes

No codes and i first changed it back in august when it first happend. But I never had a problem in the winter. I just changed it again a few days ago when it acted up again. No loss of fluid

 

[HD_LS]

No codes and i first changed it back in august when it first happend. But I never had a problem in the winter. I just changed it again a few days ago when it acted up again. No loss of fluid

On a 2001, you have an AWD transfer case with a viscous fluid coupling between the front and rear. I don't know what the syptoms of that viscous coupling going bad are, but that would be what I would start to investigate.

 

[Ventura139]

On a 2001, you have an AWD transfer case with a viscous fluid coupling between the front and rear. I don't know what the syptoms of that viscous coupling going bad are, but that would be what I would start to investigate.

I’ll have to check that out

 

[HD_LS]

I’ll have to check that out

Here are some links:
http://www.silveradoss.com/forums/topic/4312-nvg-149-transfer-case-info/

https://www.gm-trucks.com/forums/to...sfer-case-can-i-swap-for-another-transfer-ca/

https://www.transmissionpartsdistri...-all-wheel-drive-01-07-gm-trucks-suvs-32475r/

 

[Rocket Man]

Could be the front diff too.

 

[ks03]

@Ventura139 does this ever happen while going straight, or only when turning tightly?