I just got stuck twice in two different icy parking spaced with my 2004 Trailblazer. The front tire was on dry road, and the indicator said it was in 4 hi. Why was the rear driver-side tire spinning? Is the four wheel drive inactive? The front tire should have pulled it out, right?

ABS systems are designed to engage when braking suddenly causing tire skid/spin...the system is designed to pump the brake pedal and the driver should hold the brake pedal down firmly...DO NOT PUMP...the ABS does this for you.

Most 4WD systems are designed to be shifted in and out "on the fly". It is less stressful for the drive train doing it while in park however. 4WD does not like cornering - especially on "grippy" surfaces such as dry asphalt (why would you need 4WD on dry asphalt, anyway?). Dry asphalt is really tough on 4WD as the the tires may have minute differences in circumference as a result of wear and since all are spinning at the exact speed (even going straight ahead), those difference add up and strain the drive train. Slippery surfaces allow the tires to slip away those differences as soon as they begin to appear. Even wet pavement allows this to happen, tho not as easily as grass, dirt, snow or ice.

Drive in a tight, complete circle on dirt and you'll see that there's a shorter path of tracks for the inside tires than those on the outside. Yet, the 4WD locks all wheels to turn the same amount. The jerking during the cornering that you're feeling is the inside tires trying to spin to "catch up" to turning at the same rate as the outer tires. See the video linked below.

Check your manual and you'll likely be cautioned against running 4WD on dry pavement for these reasons.

I would try taking the right tire and cv axle off there next to the oil pan is a part that the axle slides through.it has a connector that engages the axle or 4x4 but if it is dry it will need to be replaced or checked out.it is kind of hard to take all of that off but check it out

Hello,,you may have to much stress on the drive line system,if on dry ground jack up one of the front corners so the tire leaves the ground,if oyr in a wet of icy area spin the tires a bit to relieve the stress,, also must be stopped or in park to shift in and out,,you could also try backing up a ways in case front accuator isnt releasing properly,,good luck.

If the 4wd was engaged on dry pavement you would have a difficult time making a turn because the front tires would be turning at the same time.
If the bump or vibration is felt when you are driving down a straight road I would agree with the ball joint or other suspension theory.
I will note here that Jeep Cherokee came with two different kinds of 4wd, one version can be driven on dry roads when engaged.

Sounds like you have a wheel bearing starting to go bad. If it gets worse when you turn left than the right side is usually bad. If it gets worse when turning right than the left is usually bad. Sometimes you can jack up the vehicle and spin the wheels by hand and hear/feel the bad wheel bearing. Also sometimes you can grab the tire at the 12 and 6 position and push/pull and feel the tire move. Another indication that the wheel bearing is bad.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

I have a '02 TrailBlazer and I had the same problem. When I got a flat and went to change the tire on the side of the road I was not able to get the tire off the winch. Luckly, I have AAA and the driver knew the trick to getting the tire free. The process involved lowering the tire as far as it would go and then kicking it. Wind back up and repeat until the winch free's itself.

When I took the car into the shop to get the tire fixed and the have the spare put back on the car, they were not able to get the winch free enough to put the tire back on. They said that is is a common problem with this mechanism and suggested replacing the winch system (estmated parts and labor $215). From what I can tell the winch accumulates rust up in the cable and locks up.

Test the tread depth, see how close it is on all 4, Toe-in setting is supposed to point the front tires toward each other very slightly. On a dry surface in 4x4 if you turn a tight circle you should feel skipping when the tires pull against each other. Caster, camber and toe in should have all been checked on all 4 wheels. With newer cars that have traction control and antiskid, the old methods of alignment are not any good. It is quickly becoming quite specialized.

you normally have different psi in the front than the rear is because of the weight difference.

  The clutch in the transfer case is burnt up and fused together therefor binding the powertrain. If you continue to operate it like this it will destroy the front differential and possibly the rear differential. It was most likely cause by the tires not having equal circumference either due to a mismatch of tires (different brands although the same size is indicated on the side wall will have different measurements,I have seen BF Goodrich tires have a different size because speed rating was different although the model was the same) or lack of tire rotation during the life of the tires.. If the measurements are not with in 1/4 inch around the center of the tread this will cause your concern. Tires should always be replaced at all 4 corners on all wheel drive vehicles.