I have 200,000 in it so far. I have owned the truck since 30,000 and have NEVER changed the fluid or needed to add anything. Its a 2004 Z71 5.3L 4x4 with 35's on it. up untill last weekend it had 3.73 gears now it has 4.56. so I did the gears and this weekend doing a cam ,springs ect... My question is do I need to change the fluid or let it be untill it "gives up the ghost"? I know old school was just let it be but is the newer stuff the same?

 

I just let mine ride tell it explodes lol, but im only on my 4th 4l60e... people say if you put fresh fluid in a high millage trans the new fluid is to slick and makes the trans slip. all i know is you need to start saving cause that trans is most likely about to fail. i wouldnt waste the money or time changing the fluid, the cam swap is prob going to be to much for that high millage trans...

 

I agree it's on its last leg and i'm pretty lucky it has made it this far. I'll let it be and see how far I can stretch it untill the funds open for the new 60 or maybe try the 80 swap. Thanks for the input.