2004 Silverado Front End Clunking

Whatever is clunking will eventually wear out and fail.

Probable the intermediate shaft, a known defect. There is a newly designed shaft that has so far eliminated my clunking.

My 2000 Silverado 4x4 Z71 Ext LT has had a few front end rattles

when the driver's door was slammed:

Had a loose drivers door window power regulator (FIXED)

Had loose self tapping bolts on the front Cross member skid plate (FIXED)

I now have a mild 'bump' rattle after the 4 Z71 shocks were replaced at 75K miles with stiffer Monroe Reflex units. (Not Fixed yet)

i hear a lot of these trucks doing this

Its most likely the ISS, its a known issue. Use a cord/rope/chain/whatever to hold the steering wheel from turning and unbolt the shaft at each end and remove it. Squirt some grease in the shaft and use a rubber stopper to plug the end (you can get them in the hardware stores) and compress the shaft to squeeze the grease into splines of the shaft. I think this spring I'm going to drill and tap mine for a grease fitting.

So are you suggesting that GM's fix for this is to install a replacement intermediate shaft that has a grease fitting?

--Steve

GM's fix is to install the redesigned shaft.

I know that, but I'm asking what's different about the replacement?

--Steve

It don't clunk?

No, they put in the same shaft hoping it will last until your warranty runs out or you trade it for another truck. If you don't and complain loudly enough you sometimes get an updated shaft that doesn't clunk as soon as the original.

I had mine replaced out of warranty for free. Had to convince the service writer, but they did do it, so far so good.