My 89 2.3 had the transmission built at 99K miles. I bought the car last fall and now it has 157K miles on it. Do you think it's safe to change the ATF fluid after driving a rebuilt transmission for 58K miles? If I change it, I would probably use the Mobil 1 Synthetic fluid.
I've heard that once you get past a certain point with automatic transmissions, changing the fluid will cause more harm than it'll help. That might just be redneck folklore though
I posted this on TF earlier this evening... didn't feel like typing it all out again....
there is truth to that statement, however, you will likly not see problems with a change at that milage. As you get closer to 100K miles without ever changing the fluid, there can be significant deposits, and so forth which the new fluid with lots of detergents can pick up and move somewhere else to cause problems. It is also possible for these deposits to be in the correct places, such that they make up the clearances after wear has taken place, and lastly, you can create new leaks by removing these deposits.
I don't think you'll have trouble at the 58K mile mark, but you had better do it soon.
On the other hand, if you have regularly changed the fluid as perscribed, there would be no worry about changing the fluid on a high milage transmission.
I use synthetics in my engine, but as for the tranny...I'd say stay stick with what youre using. I have 106k on my 89 lx and I am just about to do a ATF change, just got the Castrol stuff. I just figured that if its been using the regular stuff and working fine, why change it, cause synthetics aren't gonna give you much in the tranny. I say keep synthetics in the engine.
If the fluid is real black in color and/or smells burnt I would not change it at all. I work in a transmission shop and we have done service on tons of cars with nasty, smelly black fluid and the result is usually slipping shortly after.
If it looks clean and transparent red in color you should be OK.
One more thing, if you are gonna change it, add some Trans X. I swear by this stuff. Just follow the directions exactly! Dont over fill and your tranny will be renewed.
tranny fluid like all the fluids in the car have additives. over time the additives break down and reduce the perfomance of the fluid. tranny fluid has additives to help disperse heat for one, heat is a major cause of trannys. heat breaks down the aditives faster which causes more heat etc. if the tranny isnt slipping, there are some things you can do, there is a service called a T-TECH which changes almost 100% of the tranny fluid by intercepting the tranny line and using the tranny pump to push the old fluid into a machine and the new fluid runs back to the tranny. but the filter in the tranny should be changed too, and if there is a magnet in the pan it may be full too. i work in a shop that does these. i have seen some cars come in with slipping, and after the t-tech it stopped, ( we are told to check for slipping before we do the service, then they have to sign a waiver cause it may not help) as far as synthethic, if you have any leaks at all, it could make them worse. synthetic additives dont break down as easy but it also may "clean" spots of build up in high milage components causing a leak. more in engines than trannys though.
if it was me, i would drop the pan, change the filter, clean the magnet and drain then get the 100% fluid change service. (with non syn ATF) but if you do, make sure you recheck the level after you've driven it for a few hours. the new fluid going in is cold and ATF expands when hot.
Sounds good guys. My fluid is red in color and doesn't look very polluted. I don't think changing it will cause too much of a problem, but as said, if I'm going to do it, I shouldn't wait any longer.