I have 160,000 on my Regal GS with the original trans. I've been debating with myself if I want to change the trans fluid. I've heard that sometimes with higher mileage trans, when you change the fluid it could just make things worse. What are everyone'* thoughts on this?

I might add that I am starting to get a little slippage putting it in drive.

Flushing may not be good but changing the trans fluid is a necessity! The friction modifiers do break down on all ATF'* which then helps to wear/ build heat & then worse.
Plus the filter should be changed too!
bONUS- u also get to look inside the pan & find out how much particulate matter ie clutch plate /metal shaving etc are in there. Mine is clean as a whistle, but then I do trans service every 35k miles period.
Do your service & add to DEX VI (6)
LUBEGARD Automatic Transmission Fluid Protectant

PS:
Then Your minor slippage will probably be gone as the new fluid with new friction modifiers & Filter will all work properly again on the computerized transmission.

I know when i worked at the Chevy dealership. If someone had a vehicle with that many miles and the fluid had never been changed. We would warn them that if we changed it; it might have worse effects than if we didnt touch it. Alot of them with high mileage that had never been changed would come back and need a trannsmission within a few thousand miles.

New fluid will not fix seriously worn clutches/ trans. I guess the debate is open.
Did your customers tell you of problems before warning them or...they just came in asking for a change at that mileage?
Many customers would not tell dealership of the problems hoping fluid would solve their problems?
Really they dont want to pay for a complete scan to obtain codes first either.
Those customers may have just been hoping new fluid would fix all their problems.
Then since fluid filter change did not work, it was time to really fix their problems.
Personally I see no harm in changing fluid & filter in a serviceable transmission and restoring the fluid to the new standard of DEXRON VI which is a way better synthetic fluid.

They didnt have any problems. We warned them that after 100,000 plus miles or more. And it never been changed it could cause problems and it prolly be better to not change it. The newer ones im not sure about with the dex 6. That came out in the last year i worked there. I know they have longer change intervals. And possible if you did change the higher mileage with the dex 6 it might be ok.

Derek has your trans been serviced before? Does you fluid smell burnt or dirty?
Try having a scan for trans codes performed.
When I got my Park Ave at 75k miles it had P1811 code long sift max adapt, upshift problems when hot, taking too long to shift & kinda clunky (felt like it was slipping into next gear) 4T65E trans.
As recommended by forum members I installed the spacers /springs etc into the accumulator inside the pan area so it was accessible, with the 4T65E Transgo shift kit with Dex 6 & lubegard red and now it is perfect.
It also was a huge relief to see into the pan of course with no particles inside on magnet.

If a transmission flush causes problems, those problems were headed your way anyways. If you want to delay the inevitable I can see not doing a transmission flush but there is no reason not to do a pan-drop oil and filter change. That gets the new fluid your transmission needs without disturbing the things you don't want to disturb in an older transmission.

I strongly recommend a pan-drop oil and filter change. While you are at it, for very little extra work I would also install a shift kit to get those shifts a little crisper.

I'm not 100% sure about the trans service history. I bought the car in January 2011 with 137,000 miles on it. It was purchased from my cousin so I can ask him. Then again he bought it with high miles from the original owner so I'm not sure how many questions he can answer.