Automatic Trans Slipping in 3rd gear.

[Tipsey Hussle]

Recently got a 06 Silverado and now the Transmission is slipping going into 3rd.

does fine 1st and 2nd.   No 3rd.   Then kinda just rides high in 2nd .   
I’ve read this seems to be a problem with a lot of the trucks of this model.  This Trucks has 220k miles.  And the former owner said they don’t know when the last time fluid was changed.  That it was probably Atleast 50-60k ago.  If not more.  
 

so my question is.   Would going to have the transmission fluid changed help this problem out ?   Or is it a waste of time and $$   , or the trans if probably screwed by now ?   That it needs a solenoid or other repair ?    
 

Just seeing if anyone else had this problem or what there fix was ?  Or any advice on a budget.   Thanks     
any replies greatly appreciated 

[shakenfake]

You could change the fluid but if the transmission has never been rebuilt then it is about time

[Tipsey Hussle]

Far as I know it never has.  But if fluid hasn’t been changed in who knows how long.  I didn’t kno if that may help a while.  Wasn’t sure. 

[Black02Silverado]

It might not make a difference but for the cost of fluid I would change it out and see what happens.

[Brian715]

Classic 4l60 failure. Not sure I would waste the time oe money on a fluid change. She's toast. I've had a couple go out with those exact symptoms.  Honestly 220k is pretty good for a 4l60. A couple of years ago you could get a rebuilt one for about $800. Not sure what they cost now. 

[It's Tim]

What's the fluid level and condition?

What condition is the truck in?

Can you justify the expense of putting a transmission in it?

Edited September 16, 2021 by It's Tim