My 4Runner is stock. I took it officially off road today on dirt and rock hills/banks, and through some red clay and such . Then i was driving home and for about 4 seconds heard a high pitched singing/screeching/ringing sound . I know I couldnt have possibly pushed it too far, what could this have been? How far can they be pushed stock?

 

I have seen stock and nearly stock rigs go some amazing places. It's hard to imagine from your description that you were even coming close to the limits, but I wasn't there.

You probably got a rock caught in the brake backing plate or something equally harmless.

Now, if you posted that you ran the Rubicon Trail in a stock rig, I would say you were starting to push the limits there...

 

mud in the brakes?

 

I'm sure the screetch is coming from the dust plate on the front/rear brakes singing away.

 

Now that IU think about it, I was throwing it around once driving away. My suspension is stock with 121000 miles on it. Too many to off road?

 

Barely broke in, in Toyota terms. Go through it, look at the various components, then upgrade/replace anything worn. You will be fine.

The first thing I would check is the shocks...