Universal Joints going bad or transfer case?

[jbres]

My 2003 Tahoe has been making this "clunking" noise for about a year now but is getting progressively worse. Whenever I put it into reverse, I hear the clunk. Whenever I am driving and decelerate as coming to a light, then I tromp the gas to get back at it, I hear the clunk. It almost feels there is slack in the driveshaft...
I got underneath my Tahoe and the rear driveshaft when in park doesn't move and doesn't rattle. The FRONT driveshaft rotates with little effort even when in park.... When I put the e-brake on and Tahoe in neutral, the rear driveshaft feels stiff as it should, and the front driveshaft is like a dead fish and rotates easy as can be... Hopefully this is a sign my universals on the front driveshaft are bad??....Took it to my transmission guy a few weeks back and he said trans is fine...
Baby is coming any day now, and hoping its not my transfer case, because I don't have thousands to spend....

Tahoe is a 2003 with 123,000 miles on it, and very well serviced and taken care of by myself.

Any opinions? Thanks alot

[jbres]

looking closer at the factory front universal it does not have the grease fitting but does look almost like grease has spewed out of it over time... Also, I don't hear the high pitch whine but it louder now when "Decelerating" than it ever was in the past. I feel as if I can hear it gear it runs though...(This could be due to my 17" All terrain tires)

[jbres]

hmmm my Tahoe is 4 wheel drive only when I select it on the dash. I never had this "clunking" in the past until about 4,000 miles ago. I am starting to doubt taking it on long trips because of the noise.... Nobody thinks it my front drive shaft universals?

[mnm_2]

u-joints are going bad,replace with new joint that have grease fittings,they are not very expensive.sometimes the joint will feel tight but the factory grease will be gone and start wearing the cross and that is the clunk you feel,I have had them even make a high pitch whistle sound when the joint goes dry.

[enblethen]

Is the Tahoe all wheel drive or is it part time four wheel? Part time four wheel in 2 wheel drive selected in transfer case, the front drive shaft will turn very easily.
I would say the rear differential or transfer could be suspect.
Jack up the rear of the rig (both wheels). Turn drive shaft to see how much slack is in the rear differential ring and pinion.

[1oldtruck]

Sounds normal to me. My truck exhibits similar issues but never a problem with 86,000 miles. The front drive shaft is "loose" when turned compared to the rear. My truck was at the dealership less than a year ago for wheel bearing replacement. They explained the slack in the front shaft is required to avoid binding when turning in 4WD.

I don't think it is anything to do with the transfer case. I have replaced one in the past on a 2001. The problem with that one was the chain slipping on the sprocket. It was obvious when accelerating. You could feel and hear it. $1300 to replace after 200,000 miles.

Is your Tahoe 4WD or AWD? Both of mine are AWD.