I have a 1998 Dodge Caravan SE 3.3 liter with automatic transmission. I don't have overdrive. The transmission is working fine but I want to change the fluid because it has 138K miles and I just bought it and don't know the history. Now I heard from a mechanic and some friends that I should not change the fluid because I will experience problems. i read some post on this forum about flushing the fluid by disconnecting the hose to the radiator and starting up the van and add new fluid as the old fluid is spraying out of the hose. I read a post that says to drain 3 quarts and run it for a few months. I read another post to not take it to a dealer to have it done because their high pressure flush machine will stir up debris and weaken the gaskets.

I am at a loss of what to do. I am not a mechanic but more of a handyman. I never worked on automatic transmissions before.

I also have a question on the type of fluid to put in it. My Haynes Manual says to put in ATF3. The auto parts store says to put in ATF4 if I have high mileage. Other post on this forum says to only put in ATF4.

Could someone help me with this issue? Or maybe I should take it to a transmission shop? I'd hate to mess up my tranny when there is nothing wrong with it at the moment.

 

There are pros and cons to machine flushing. And, there are risks in flushing a transmission that's been neglected. The first question you should ask is what condition is the oil in right now? Is it red or brown? Does it smell burned? Abused oil really stinks. If it's not burned, you should be ok to change it. You can drop the pan and change the filter. That will change about 40% of the total fluid. Then repeat it again a year from now. Or, you can do the line flush procedure.

What you should NOT do is a machine flush where they flush with cheap Dexron, and then add a "friction converter" to make it mimic ATF+4. Either flush with ATF+4 or don't do it at all.

You can read the arguments on both sides here:

http://www.ricksfreeautorepairadvice...-the-right-way

 

Thanks RickMN. Holy cow! What if the mechanic lies to you. Who can you trust. I better do this myself. I am thinking about just replacing the filter and draining what I can through removing the pan. This is so complex and it seams like one wrong move can destroy my tranny. I should have gotten a stick shift.

Oh yeah, should I use ATF 4 or 3? My Haynes book says 3 but I heard 4 from Advanced Auto and other sources.

 

Atf +4 is what you want
it is the newest and fully compatible with atf+3

and Chrysler has allowed other company's to license the mopar atf+4
you can find the aftermarket approved atf+4 here
Licensed ATF+4® Brand Names

http://www.centerforqa.com/licensedatf4brands.html

 

any my personal choice in your situation with not knowing the vehicle service history is to remove the pan drain and change filters, then repeat in a few weeks

or add a drain plug so you can drain it easier, I drained mine 4 times, after every 100miles I drained the fluid again, gets you the majority new fluid with out any of the arguments of a flush or not too flush

here was my post, https://dodgeforum.com/forum/dodge-c...rain-plug.html

 

Thanks Rick
royt911 use ATF+4 fluid.

 

Thanks everyone for your advise and links. I will give it a try in a couple weeks.