works like a charm, problem gone within a week.
replaced fresh ATF + addictive

That's great !
Can i know which specific additive you used ?

Glad that your auto trans is sorted out whilst saving (or not conned of) a ton of $ from an overhaul expert .

Why not refresh with new ATF fluids first without treatment additive (especially when the 'old' outgoing ATF looks nice ,pinkish and not dark coloured ) and see how it goes from there ?
If need be, refresh ATF fluids for another time or two , if further improvement is desired .

This post has been edited by zeng: Jul 6 2020, 01:13 PM

i used lubgard platinum

I was told that if the problem goes away after the engine/transmission gets warmed up, cleaning/flushing it would probably work.

Hi zeng, I have already replaced my ATF and the symptoms still persists.
If the additive cost the same as a ATF change, I might as well give it a try.

K&W ATF additive isn't too expensive and very widely available/imported.
give that a shot for high mileage vehicles

Can try adding addictive. Maybe will works temporary for 3k to 5k kms
If internal gearbox wear out, need to overhaul or recond unit.

If symptoms persists after new ATF replacement , then it certainly makes sense to use proper treatment additive in your case .
The point here is to (slowly, in my approach of no treatment) 'smoothen or unstuck' transmission control valve .
Appropriate treatment additive is more powerful cleaning stucked control valve IMO equivalent to steroids/anti-biotics .
In case you are not quite happy with the result after first fluid change/treatment additive , can always repeat the whole process again before you give up and surrender to overhauls/transmission exchange .