transmission advice
 

i have an 86 rx7 that has an auto transmission. i got the transmission put in about a year ago used, and i want to get a tranmission flush done on it but i have been told that tranmission flushes for older cars is not good for the transmission. is that true?

owners manual for the 86 rx7 recommends replacement of the automatic transmission fluid every 30,000 miles.

I have heard somewhere that new fluid can fuck up a dying tranny, but if it is dying I would rather that it dies in front of my house instead of driving to school or work! Anyway just change it every 30K (I do it every 20K tho) and you should be fine.

If you change the fluid like you are supposed to you are fine. But if you dont and lets say for example your transmission has 160 thousand mile on it it wouldnt be a good idea. Reason is the thick dirty old tranny fluid is what is keeping your gears in the transmission in contact and making up. so when you take the old thick stuff out and put the new thin stuff in then the gears dont fit together like they are supposed to and you end up with problems. but that isnt always the case but that is why some people say dont change your fluid on a older car....but what needs to be added to that statement is dont change it on a older car if it has never been changed before. One of our work vans had close to 300,000 on it before we changed it but we changed it because it was messing up so we really had nothing to loose. after we changed it and the filter it was fine. but it was also a rebuilt tranny. se it probally had around 150,000 miles on it instead of 300,000 miles on it.
later

Well said Greys10th! That is pretty much what I meant :D

Yhep, if the fluid is burnt, my .02 cents is not to change it. The burnt ness and dirtyness is allowing everything not to slip or to function as normal. ATF has lots of detergents/cleaners in it. Old phucked up transmission with new fluid may not work well (slipping is the main problem). Take a whiff of the fluid, if it's burnt, no, if it smells nasty but not burnt, I'd say replace it.

If all heck breaks loose, save the old fluid to put back in if the new fluid phucks everything up.
:D

okay but what do i do if i dont know what shape the transmission was before i got it?