So I've got a 2001 tahoe that I've only had for about 3 weeks that drops gears and regains them at random(usually after towed or pushed while running). While driving there's this constant grinding scraping sound almost like an axle being stripped up, then it'll start grinding gears (both reverse and all drive gears). First time messing with an automatic transmission on my own so would like some advice.

 

Welcome to the forum from Oregon.

I think any transmission tech would road test that rig and then tell you the transmission needs rebuilt or replaced. Sometimes when enough metal has floated in the transmission fluid thru the system, the case is no good. Get a trusted transmission shop to help and if you don't know what you are doing or are not mechanically inclined, let a trained tech do the work. These 4L60E transmissions are typically good for 150k-200k miles. If you tow enough with it that could be the source of the problem if it is not set up with a tow package and have a large transmission cooler.