Rear end wine - 2000 Chevy K1500. Sounds like the axle bearing but not 100% sure. Never replaced bearings in the rear before - not sure what I might be getting in for.

Elisa where ? are you working at, EXACTLY?
sounds like it's wheel /axle bearing, is it?
or the pinion bearing????? there are many bearings in any axle.

id bet $100 you didnt just pop in a new rear crankshaft bearing
as other poster guessed.

my guess is the rear axle seal leaked, GL5 lube
and soaked the brakes and all? or the front pinion?
the job requires, all Gear lube, be cleaning off all parts there.
after the job ends, or it will leak RESIDUAL GL5 (imagine a kitchen sponge?)
which axle , the 198RBI or the 226RBA??

this seal., must i guess?
so if this seal leaks, its because the bearing is bad, and beat the seal to deathh.
#1 cause.
when it leaks goes all over.
the rear has discs but has TopHAT, emrg. brake shoes
and those will be wrecked, (soaked in GL5 lube and leak after
and the shoes are wrecked too.) so did you clean all that and replace all that. (i can guess what you did or touched,)

That sounds very bad, Jorge. Don't drive it any more until you can either get the differential rebuilt or get the axle replaced with another good axle with the same gear ratio.

first up jack up the vehicle and remove the damaged wheel
fit the spare tire and then place an indicator ( rod on a brick ) close to the rim of the spare and turn the wheel
if the axle of hub is bent you will see the rim get closer then further away from the indicator as you turn the wheel
if it is , replace the axle and bearings
if not there will be no axle damage but the bearing could be "brinnelled "( a bearing term where the balls or rollers have been imprinted into the race from impact) in which bearing failure will become evident in 10-20,000 miles
next step is to go and get a rear end wheel alignment done as there could be suspension damage that will cause handling and tire wear problems

To replace pinon bearing you need to pull wheels and the brake drums off next pull cover off the back of the rear end (make sure you have a drain pan under rear end) next turn dive shaft till you see a small bolt remove bolt pull center pin out push axle in pull c clips out pull axels out remove four bolts holding ring and spider gears remove gears assembly next remove drive shaft remove bolt from pinon push pinon in remove seal and bearing

I am sorry to tell you this, but you will have to take the Truck to a Rear End repair shop to do this. If you are very mechanically inclined and have all the specific tools like a slide hammer, bearing puller, bearing installation tool, etc. If you have tools like this, then I would get yourself the car manual. To replace the bearings you will have to remove the axles.

Not terrible of a job to do. You will have to jack up the rear end and support it on stands and be sure to chock the front wheel so it does not roll forward while jacking it up. Remove the rear wheels and the drum assembly or rotor if disc brakes. Remove the rear differential cover be sure to have a drain pan to catch the fluid that comes out of it. Find the center carrier you will see a pin about 3/4 of inch in diameter going throught the center carrier with a bolt on one end remove the bolt turn chunk until pin comes out. Push the axle in enough to let the c-clip to be removed then pull out the axle. You will then have access to the axle seal and axle bearing. You will probably need a bearing puller with slide hammer to get bearing out. Then put back together.

Section 05-02A: Axle, Integral Carrier — 8.8-Inch Ring Gear 1994 Town Car, Crown Victoria/Grand Marquis. Workshop Manual REMOVAL AND INSTALLATION Axle Shaft NOTE: Whenever replacing the rear axle lubricant, use Rear Axle Lubricant XY-90-QL (ESP-M2C154-A) or equivalent.
Removal
CAUTION: The rear brake anti-lock sensor must be removed before the axle shafts are removed. The rear brake anti-lock sensor is bolted on the rear disc brake caliper anchor plate.

1. Raise vehicle to desired working height. Refer to Section 00-02 . Remove rear wheel (1007) and tire assembly. Remove rear disc brake calipers (2552) and rear disc brake rotors (2C026) .
   
   
   
   
   

1. Clean all dirt from area of axle housing cover with a wire brush and/or cloth.

1. Drain rear axle lubricant by removing the axle housing cover .

1. Remove differential pinion shaft lock pin and differential pinion shaft .
   
   
   
   

1. Push flanged end of the axle shafts toward the center of the vehicle and remove the rear axle shaft retaining u-washer from the button end of the axle shaft .
   
   
   
   

1. Remove axle shaft from the rear axle housing , being careful not to damage the inner wheel bearing oil seal (1177) and rear brake anti-lock sensor ring.

Installation
NOTE: Check for presence of rear axle shaft o-ring (4A332) on the spline end of the shaft and install if not present.
CAUTION: Care must be taken not to let axle shaft splines damage oil seal or bearing assembly.

1. Carefully slide axle shaft into rear axle housing without damaging rear wheel bearing (1225) or rear brake anti-lock sensor indicator (2C189) . Start splines into side gear and push firmly until the button end of axle shaft can be seen in the differential case .

1. Install the rear axle shaft retaining u-washer on the button end of the axle shaft splines, then pull the shaft outboard until the shaft splines engage and the rear axle shaft retaining u-washer seats in the counterbore of the differential side gear .

1. Position the differential pinion shaft through the differential case and differential pinion gears , aligning the hole in the differential pinion shaft with the lock bolt hole. Apply Rear Axle Lubricant to differential pinion shaft lock pin . Install differential pinion shaft lock pin and tighten to 20-41 Nm (15-30 lb-ft). CAUTION: Differential pinion shaft lock pin must be tightened to specification using Stud and Bearing Mount E0AZ-19554-BA (WSK-M2G349-A1) or equivalent.
   
   
   
   
   NOTE: Axle housing cover must be installed within 15 minutes of application of the silicone rubber or new silicone rubber must be applied.
   CAUTION: Make sure machined surfaces on both axle housing cover and rear axle housing are clean before installing the new silicone sealant. Inside of axle must be covered when cleaning the machined surface to prevent axle contamination. Tighten the cover bolts in a crosswise pattern to ensure uniform draw on axle housing cover .
   

1. Apply Silicone Rubber D6AZ-19562-AA or BA (ESB-M4G92-A or ESE-M4G195-A) or equivalent. Install axle housing cover and tighten retaining bolts to 28-38 Nm (38-52 lb-ft).
   
   
   
   

1. Add Motorcraft Rear Axle Lubricant XY-90-QL or KL (ESP-M2C154-A) or equivalent until it is 6-14mm (1/4-9/16 inch) below bottom of fill hole. Add 118.3 mL (4 oz) of Ford Additive Friction Modifier C8AZ-19B546-A (EST-M2C118-A) or equivalent to Traction-Lok axles. Install fill plug and tighten to 20-41 Nm (15-30 lb-ft).

1. Install rear brake anti-lock sensor indicator . Tighten retaining bolt to 4.5-6.8 Nm (40-60 lb-in).

1. Install rear disc brake caliper and rear disc brake rotor .

1. Install wheels and tires.

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1. Insert Rear Bearing Remover T85L-1225-AH in bore and position it behind bearing so tangs on tool engage bearing outer race. Remove rear wheel bearing and inner wheel bearing oil seal as a unit, using Impact Slide Hammer T50T-100-A.
   
   Rear Disc Brake Caliper Anchor Plate
   
   
   
   
   

1. Lubricate the rear wheel bearing with Rear Axle Lubricant.
   
   
   
   

1. Install rear wheel bearing into the housing bore using Axle Tube Bearing Replacer T78P-1225-A.
   
   
   
   CAUTION: Installation of rear wheel bearing or inner wheel bearing oil seal assembly without proper tool may result in an early bearing or seal failure. If inner wheel bearing oil seal becomes cocked in bore during installation, remove it and install a new one.
   

1. Install the inner wheel bearing oil seal using Axle Tube Seal Replacer T78P-1177-A. Use Premium Long-Life Grease XG-1-C or K (ESA-M1C75-B) or equivalent between the lips of the inner wheel bearing oil seal .
   
   
   
   

1. Install axle shafts as outlined.

Not 100% sure on that vehicle & don't have manual on it at this time, but will say very common that it does have "C" like clip at end of axle. Large pin comes out first, then push axle in slightly & remove clip, & slide axle out.

Check to see if the drum is hotter than normal. If the bearings are bad, you have to lift the truck and remove the axle. Remove the wheel drum until you get to the axle. They to remove the axle, you have to open the rear end Spider gear ***** at the middle. They have a half moon wedge or a clip you have to remove. They you pull out the axle.Replace the bearing grease it and seal it. Then put it back in the reverse order. Sounds simple but it is not that simple. Takes work

You say the rear wheel axles and bearings have been replaced, you mention nothing of the front wheels, you have the symptoms of a front wheel bearing being worn out, remove them and check for pitting in the bearing rollers or the bearing races, I am sure you will find a problem. Hope this helps solve your issue with the bearing noise.