Well I went to a auto repair shop and i told them i dont know if the tranny was ever flushed on a 1995 pontiac bonneville and he says if it hasn't been flushed by 110k miles dont flush it. The fluid will be to thick and chances are that your bands wont handle it

Is this BS?

That all depends on how you drive your car. If you take it easy then you might be able to go that long before your tranny flush and be fine. I got mine last week I have 78k on mine. Two days later first gear is acting up. But he isnt lying to you. The tranny uses all the slop to help it work. Get rid of all the slop and it will cause slipping.

I did a flush at 80k, did wonders for me. If your fluid dosn't look or smell TOO bad, you'll probably be ok. Get a second and third professional opinion.

I haven't bothered to touch the tranny on my 90 SSE just for that reason. It has just over 182,000 kms ( about 110,000 miles). The fluid looked pretty good but I didn't want to take a chance and dislodge some crap that will come back to haunt me.

I may just get the filter changed and new fluid but even then I may hold off till it goes. Which I know it will since I don't think it was ever rebuilt yet.

If they have the right equipment they should be able to get all the crap out and your tranny will love you for it. I get mine flushed every spring.

ive been told every 20k miles on a hard-driven performance car...

Personal opinion here. Do a tranny service every 60,000km or 45,000 miles. To get all the fluid out run the engine with the outlet cooler line disconnected until it runs out. Drop the pan to get the rest and change the filter. Fresh tranny fluid (tranny fluid in general) has got a ton of detergents in it and if changed regularily should keep the tranny clean. A tranny flush is only useful for an extremely dirty tranny.

Is there a risk of damaging the transmission when draining by running the engine till the transmission "pumps itself dry" through that cooler line you speak of?

nope, been doing that forever not one problem ! just dont' run it long after the fluid stops

Ditto