Slipping sound when accelerating hard or uphill

2007 Toyota Tacoma V6 Automatic

My truck has been making a slipping, sound when I accelerate hard or am slanted uphill. If I start accelerating like normal it doesn't make the sound, only if I accelerate hard. Now the 4x4 light flashes.. not sure if it is connected or not. The first shop I took it to thought it was a bad transfer case motor but couldn't fix it. Sent me to a Transmission shop. Transfer case motor switch was bad so replaced those, still not fixed. Transmission shop said they couldn't figure it out, thought it might be electrical and referred me somewwhee else. Any ideas?

 

Not sure about the slipping sound, are you spinning the tires maybe?
The 4wd problem we can probably figure out if your willing to do some electrical testing.
https://www.tacomaworld.com/threads/4wd-system-operation-help-thread.742420/

 

Slipping is the only way I can think to describe it. It's not the tires.. it's like parts sliding together and clunking while turning. Maybe something trying to engage?

 

Not sure, it could be alot of things. Can you post a video of it?
You will have to put it on a video sharing site like youtube and post the link to it here.

 

Here's the sound. Not sure if it's related, but the 4 wheel drive light is blinking, (4H works).

https://youtube.com/shorts/VJUDMtY_42M?si=xKBKMOZJMqrixPhm



I'm going to see if I can do some of the electrical testing mentioned above.

 

I'm thinking u-joint or carrier bearing maybe, hard to say.
Definitely something in the driveline, as loud as it is it shouldn't be too hard to find.

 

It ended up being the carrier bearing.