Rear wheel locked up forward only (brakes OK)
 

Hi!
I have an issue with left rear wheel. It seems to be locked up in a forward direction only.
The car is jacked up, rear wheels up, transmission in neutral. Right rear wheel spins with no problem both directions while the left rear wheel spins only backwards, can't move it forward.
I noticed the problem in the freezing temperatures only. Something was terribly knocking from the drivetrain when driving.
What could this be? Rear diff? Wheel bearing?
The rear diff fluid was changed ~20k miles ago.

Will the wheels rotate in opposite directions when in park?
Have you checked the U-joints?

When in Park and spinning:

• right forwards -> left backwards
• right backwards -> left stuck
• left backwards -> right forwards
• try left forwards doesn't even move

Left only moves forwards when D and gas pressed but with problems and terrible noises.

That's an odd one. I'd make sure the ebrake components on that side have not become loose and bouncing around in there. Maybe try using a breaker bar to spin the hub so you can figure out where the noise is coming from.

ebrake meaning parking brake? oh I haven't ever touched it. Is it the similar construction as in 3rd gen? I read it is not uncommon that parking brake freezes in 3rd gen. It could be this!
I'll try to to turn it with a pry and take the brake disk off to see what mess could be in there.

Research how to properly remove the rear disk.....OR you WILL damage the parking brake shoe assembly!!!

The parking brake shoes and hardware are a BIG pain to replace so you don't want to do that job unless you have too!!!

Edit: I looked up this topic on the parking brake replacement for you, watch the videos in the first and last post for how too replace!!

Parking Brake Shoe Replacement

Thanks a lot! This is some awesome video instructions.

Yes, emergency/parking brake. I've seen some so rusted that it's a pile of parts behind the rotor/drum setup.

There was some badly rusted hardware inside the rotor.
Probably it stuck when freezing so I decided to replace it all.
I must admit it was a nightmare. It wasn't that easy as on videos. I can't remember anything worse anytime wrenching on the 4Runner.

The parking brake shoes: TRW GS8716, looked decent and the pad itself is wider then OEM. Most important it fits with no problem.

Pins were the problem. I bought two aftermarket kits. One had too long pins, both. But the other one named Carmont TOY-00358-P (FB-11-04-C) had the correct pins, but it was missing horse washers and the the bottom springs and the cap washer with bent end. I mixed it all and reused star adjusters.

After all the ebrake pedal is seven clicks, wheels are turning. The cable was moving freely. So I'm hoping it is it.
Thanks to all!

Great, good to hear you got it done. Those parking brake bits take some major dexterity and there's tips to help get it done but it's still a pain.