How do I get the drive shafts apart to change the carrierbearing on an extended cab 2004 f-150

Your local wrecking/recycling yard will be the best source for the correct information on the wheelbase length and length of the drive shafts.

1998 Chevrolet Tahoe/Wheelbase
111.5 to 117.5? the wheelbase of a 2004 Chevy Silverado ---119 to 157.5? not compatible

undo the cap bolts for the "u" joints at both ends of the shaft and take it out If it is held in with a u section strap around the bearing cap then remove them and do the same for the other end.

Usually you remove the drive shaft, then unbolt the carrier from the frame. The drive shaft slips into the bearing.

could be a drive shaft u joint

could be bent drive shaft,check rear end(differencial) fluid level

I have run into the drive shaft seal and or dust cover drying out causing a squeal. Just pull the drive shaft and put a light coating of grease on the seal and dust boot.

I'm betting they are different lengths and different size u-joints,

you have to take cap scews off the rear of driveshaft the drop the rear and pull out towards the rear

I have a '88 Ranger XLT extra cab 4X4 w/auto tranny (2.9L V6) that had a 2-piece driveshaft on it. After adding a 4" suspension lift, there was a strong vibration whenever I took off from a dead stop. I replaced the drive shaft with a beefed up 1 piece custom built by a shop specializing in drive shafts. The truck no longer had any vibration, and it hooks up immediately on exceleration. I found the shop on Ebay advertising drive shafts. All I had to do was measure the length from the transfer case/Tranny to the rear differential. The length of the new drive shaft allowed me to adjust almost 3/4" so all I had to do was get it close. I also took close up pictures so the shop could match up the correct flange on both ends of the driveshaft. The last thing I had to do was flip the crossmember brace so it wouldn't interfere with the new drive shaft.