Could it be the Universal Joint ??

Tahoe u joint labor is .7 to 1.1 hours depending on the different driveshaft combos (rear driveshaft) and the u joint part runs about $20 to $30 each

A bad U-Joint will usually squeak as you pull away from a stop, the squeak will be rotational and increase with speed initially and may then go away at 10 mile an hour or so. If a U joint is worn to that extent the shaft itself may become damage and need to be rebuilt. If the joint fails it could conceivable cause the truck to flip over. What ever the source of the noise is it needs to be checked out for safety sake.