To change a older cars ATF? (tranny fluid)

[Ottobon]

I have read a bit about how its better to either change ATF at regular service intervals or to leave it be till it goes. I believe the problem with older transmissions that haven't been changed often is that dirt gets in the system, wears out critical surfaces, but at the same time works as a effective to add friction between the plates. So when you change the ATF in a older car and all the dirt comes out your left with a tranny that has too little friction and slips like crazy.

Now currently i own a 99 Taurus and the transmission is fine with the exception that on the highway, if you lightly add throttle while cruising the whole tranny likes to shudder. I know for a fact it used to be worse (according to my sister, who had work done on it) but i'd like to minimize the problem, the shuddering doesn't happen too often, but i have a feeling its going to get worse. So assuming that all this stuff about having proper friction is true, what should i use so far as ATF for a older transmission? Are their any good additives that help out older transmissions when it comes to adding friction?

Anyways, thanks!

[jayjaya29]

I dunno, I kinda believe that idea that the transmission needs those particles for the added friction is kinda BS. I have heard from a couple tranmissions experts that its simply false and changing your ATF is the best way to keep the tranny going.

Based on personal experience, I had my tranmission upgraded, which involved draining the fluid (not a flush) and putting back in what came out (comes out to about 6 quarts in my car). Went ahead and put in synthetic ATF, couldn't be happier, my car drives noticeably smoother, most likely due to the fresh ATF.

All this was done at 77,000 miles. I don't believe the transmission fluid has ever been changed before (bought the car with 45,000 on the odo).

[Scott]

Change it... you could even power flush it if you wanted to, but that is another one of those debatable services where no one has really proven it's effectiveness.

[Aston Martin]

Tranny fluid stinks more than a trannys fluid.

[Scott]

ewwwwwww

[Lupin_IV]

Originally Posted by Aston Martin

Tranny fluid stinks more than a trannys fluid.

[tigger]

What an awesomely disturbing thread.

Anyway, change your ATF. Random bits of grime should not be necessary to proper transmission operation . For a proper friction additive use something like B&M Trick Shift ATF. Idk if it would be the right choice in such a new vehicle though. And it's not a transmission mount or something going out, is it?

[Ottobon]

i don't think a mount could shudder like your running over rumble strips, it seems directly related to operational temperature and moving my foot in the right (wrong?) way.

[jayjaya29]

Originally Posted by tigger

For a proper friction additive use something like B&M Trick Shift ATF. Idk if it would be the right choice in such a new vehicle though.

Make sure you read the back of the bottle before you buy it. I remember seeing its not supposed to be used in transmissions that were made after 2000.

I looked at like 6 different types of synthetic ATF, so many different standards and uses, picked royal purple because it was the closest to the spec I needed. Couldn't be happier with the stuff!