2003 3.8 SLE w 192,000
Tranny started slipping a little at take off with 175,000 miles on it. Changed tranny fluid and put in the shift kit. All good until about 188,000 miles. So changed tranny fluid and put in a stronger magnet in the pan. All good until now at 192,000 miles. starting to act up again on take off only. I understand about the real reason for this doing it and it being a major job to fix. Is there any other work around on this? Does anyone have a detail on how to do the real fix? Is it possible it is overheating and I should try clean the cooler? It only slips at takeoff after I have driven for a while.

It'* leaky and a tear down is likely. Valve body at least.

Are you changing the filter also?

Can you check the line pressure when it slips? That will tell us a lot. The cold pressure and hot pressure and what it does when it slips.

Yes filter is changed each time I change the fluid. How do I check line pressure?

It requires a long flex line and gauge. The ports for checking pressures are on the transaxle.

I agree with the guys above.

As a workaround, you could try adding a giant transmission cooler. It might buy you some time by allowing it to run cooler. I have one on my 1997 that has bought me around 95,000 miles (and counting) for a different transmission-temperature related issue: https://www.gmforum.com/buick-172/19...urging-310146/

Might.