transmission maintenance question
Thread Starter
Racer
Joined: Jun 2001
Posts: 377
Likes: 10
From: Chicago IL
transmission maintenance question
I had my 85 auto for a long time but I haven't put many miles on the car myself (second owner). I've changed the trans fluid and filter about 8 years ago and have put about 20k on since. Is it strictly miles on the trans that matters for fluid or should I change just because 8 years have gone by? Thanks
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
wow. That's a great question...
My thought is like this... The original fluid is 20 years old. The replacement, 8. However, the original fluid more then likely makes up about 40% of what is in there.
When most people change their fluid, they drop the pan and then replace. However, that only effects about half the fluid in the trans. I would suggest a power flush and a new filter.
Oh, I would suggest they do the same thing with the power steering. Never hurts.
My thought is like this... The original fluid is 20 years old. The replacement, 8. However, the original fluid more then likely makes up about 40% of what is in there.
When most people change their fluid, they drop the pan and then replace. However, that only effects about half the fluid in the trans. I would suggest a power flush and a new filter.
Oh, I would suggest they do the same thing with the power steering. Never hurts.
Thread Starter
Racer
Joined: Jun 2001
Posts: 377
Likes: 10
From: Chicago IL
thanks, I did drop the pan myself so I guess I have plenty of original fluid in there. I've heard some stories about 100% new fluid causing some problems - so I am a little nervous about the power flush but it seems like the right thing to do.
Instructor
Joined: Jan 2005
Posts: 146
Likes: 0
changing fluids
The problems I have run into dealt with Ford trannies. We were buying brand new for trucks, and changing the fluid at the proper times. Shortly afterwords, the trannies went. The Trans shop told us that everyone they repaired shared the same story: Change the fluid, change the tranny. I have not heard of this problem with GM. The tranny shop claimed that the torque converters relied on a certain amount of friction ofrom the oil to function. The new fluid cut the friction, and the trany would not work. My daughter made the mistake of changing the fluid on her T-Bird, and ran into the same things, as did a couple of other people I know. 
Safety Car
Joined: Apr 2003
Posts: 3,793
Likes: 9
From: VA
Originally Posted by viii
Is it strictly miles on the trans that matters for fluid or should I change just because 8 years have gone by? Thanks
However if it was my car I'd probably be changing it every 3-4 years regardless of usage. It's cheap enough.
Melting Slicks
Joined: Apr 2002
Posts: 2,118
Likes: 0
From: St. Charles, MO Route 66 Corvette Club
vii: I agree with Bogus in using the power flush method to change trannie fluid. I have read posts describing how to do this yourself using the engine of your car. I have not attempted to power flush my trannie! Most tire shopes who do some auto repairs will power flush the trannie for you at a cost of about $100. I have never heard of a trannie fluid change causing a trannie failure. This assumes two things: the person doing the work knows what they are doing and "quality" replacement oil and parts are used.
Changing the power steering fluid (flush) is an easy home job, but just takes some time in your garage. If you want info on the PS flush, send me a note to samlam@charter.net.
BTW, if your brake fluid has turned dark, that needs flushing too! As the brake fluid ages and absorbs water, it becomes acidic and goes to work on your brake components! This issue can really cost you some folding $$$$$.
SAM
Changing the power steering fluid (flush) is an easy home job, but just takes some time in your garage. If you want info on the PS flush, send me a note to samlam@charter.net.
BTW, if your brake fluid has turned dark, that needs flushing too! As the brake fluid ages and absorbs water, it becomes acidic and goes to work on your brake components! This issue can really cost you some folding $$$$$.
SAM
