# Should I change my automatic transmission fluid?



## cobb (Apr 19, 2006)

I got a ford e250 with automatic tranny, 1996 model with 200k miles. From what I can tell it was never changed, the fluid is brown like the engine oil, it does not smell and it shifts fine. 

Anyway, after some slight investigating, seems ford does not recommend changing the filter. Further investigation from other mechanics say not to even bother changing the fluid unless it is acting up. One said its ok to drop the pan and change the filter, but do not use a flushing machine. Another website for fords states to undo the return line from the cooler and drain the 5 gallons of fluid before dropping the pan and switching the filter. 

So? I want to service the fluids and other minor stuff before getting it on the road to ride. 

Whats your guys opinion, experience? What about the mexacon vs dexatron fluid to use in it? Some say the new fluids are compatable with all, others say you must use the special mexacon only brand atf fluid for fords. 

Its my general knowledge that the fluid is the blood and if you dog it or over heat the engine and damage or burn the fluid, changing it immediately can prevent tranny damage. 

Thanks


----------



## ABTOMAT (Apr 19, 2006)

When you change the fluid you're supposed to drop the pan, replace the filter, and replace the gasket. This'll get about half the fluid out. Normally that's fine, unless the fluid's bad or its been in there forever. In which case...

The DIY procedure is (after the pan fluid has been changed and it's sealed up) disconnect the return line from the cooler. Start the engine and put the tranny in neutral. Have a helper pour new fluid into the filler at the same rate it comes out the return line. When the return line fluid runs clear you can stop and hook it back up.

Power flushes, chemical cleaning flushes, etc are bad unless you have a crapped up transmission and nothing left to lose. At a minimum it won't do anything, at worst it'll bugger up the tranny. I get the impression that these machines were invented for quick-lube joints that want to move customers in and out.

Now, dealers do have a machine that will do the automated version of the DIY procedure. Just replacing the fluid through the lines using the truck's own pump. This is fine, but you want to replace the filter and pan gasket at the same time.

Use only the fluid type recommended for your van by Ford. In the past it was Dexron/Mercon, I don't know what they're using now. Once you find out what fluid is recommended, then you can find an aftermarket brand and make sure it specifies what standards it complies with. All-in-one snake oils should be avoided.

At least you don't have a Chrysler product. Most modern ones need ATF+3 or +4, which is about $6/quart from a dealer.


----------



## nirad (Apr 19, 2006)

I used to work in a tranny shop for a few years. If your Ford tranny has 200K miles, leave the fluid alone! Chances are that a fluid change will not help. I have seen where tranny services with that many miles on them will actually fail in the distant future. Reason being is your fluid now is varnished and brown. Putting fresh fluid in will loosen/wash out this varnished coat off of the internal parts possibly causing failure.


If you do service the trans, be sure to drain the torque converter. Most fords have an access cover at the bottom of the bell housing. We "bumped the engine around with a remote starter button (also disable the run wire off of the starter solenoid.) Bump the engine around until the drain plug is on the bottom. IIRC it is a 5/16 head bolt. 
The way to tell if the tranny has ever has been serviced is to drop the pan. If you find a mushroom looking plug with a black o-ring in the pan this tells you that the pan has never been off. This plug in perfectly normal. When the vehicles are assembled, the trannys come from their assembly plant without dipstick tubes. The reason for this is that there are a slew of different dipstick tubes that may be used with that transmission. Vans for example have a very long tube compared to your truck. This plug is in the hole where the dipstick tube should be for shipping to the final assembly plant. When the chassis meets the body, an assembly worker puts in the appropriate dipstick tube for that specific body, forcing the mushroom plug into the transmission pan. Over the years we had quite a collection of these plugs. They also were most excellent to fire out of our blow guns.:naughty: 

After draining the converter and dropping the pan, replace filter, pan gasket, and omit the plug (it wont hurt if you leave it in but there is no need). Put at least 4 qts of fluid in before starting. Start engine and add fluid until full, occassionally bumping it through the gears. Do not overfill. After that, check for leaks, take a test drive and re-check your fluid.

I hate to be so long winded, but I have done a slew of these services. We used to do fleets of Crown Vic cop cars.:sweat: I kind of feel like a resident expert on tranny sevices.

Good luck in whatever you decide to do


----------



## IsaacHayes (Apr 20, 2006)

Yeah, don't flush it, or it might start slipping later. If you insist, only drop the pan and do the filter, as that doesn't drain it all out of everything.

Ive done the pan on my gm 4T60-E at 110k, then at about 140k I did a full flush, agaisnt warnings because I was having issues. Later I added some seal conditioner and all my problems went away and it's like brand new. I was lucky it didn't start slipping after the flushes...


----------



## Tooner (Apr 20, 2006)

Change it or not? That question can be hotly debated for sure, so I'll stay out of it. Personally though, if it was mine, I'd change it.

As for what fluid to use I would stick to whatever the owners manual recommends only.

Below is a link to the procedure that I use on my Ford. Though it is for a slightly newer diesel vehicle I would think it would be pretty much the same for yours. This site has alot of knowledgable guys on it and you may want to post your question over there also. 

http://www.thedieselstop.com/faq/1999faq/Maintenance-AutoT.htm


----------



## scott.cr (Apr 20, 2006)

A lot of the time when overdue ATF is serviced, the reason why techs won't use a power flusher is because the old ATF will be saturated with clutch pack material (paper). The old fluid has permitted excessive wear and once it's gone, so is a lot of your friction material.

I had a 1996 E250 van (4x4 conversion) and changed the ATF when I bought it because the trans was slipping when it shifted to 2nd and 3rd gears. Changing the fluid didn't help, but I did add 1 quart of ATF friction modifier and that helped tremendously. I bought it from one of the supporting dealers on the bobistheoilguy forums.


----------



## VWTim (Apr 20, 2006)

I've never fully understood the reason to not change old dirty broken down fluid. I've heard all kinds of stories, but nothing that's been confirmed first hand. Depending what model tranny it is, you may or may not have a torque convertor drain as mentioned, but it would be a good idea to drain in addition to the pan/filter.
Also being '96 I'm pretty sure it's only going to need Dexron/Mercon 3, Ford went to Merc5 on some trannies in '97.


----------



## springnr (Apr 20, 2006)

Old fluid may have particles which help with friction as mentioned earlier. New fluid won't have particles and will clean some. 
So if the tranny has problems that are being mask then new fluid will hasten the need to repair. 

If mine I would probably not drop the pan or mess with the filter. 
Instead I would opt to use the return line from the radiator cooler to let the engine pump/remove two gallons then add two gallons of fresh fluid and drive around 1000 miles, then repeat with two more gallons/1000 miles, then repeat with two more gallons/1000 miles. 

If it is running fine after 6 gallons of fresh then consider dripping the pan to clean it and change the filter. Or just be happy with mostly new fluid in an old tranny.


----------



## IsaacHayes (Apr 21, 2006)

Yup. I know someone who works on highway patrol crown vics. Flush the trans and then it goes out shortly.

You get a "sludge" built up on the clutch packs, and a fresh flush will wash/disolve that away, and in that sludge is a lot of your friction material. If the clutch pack is worn a lot, then you'll start slipping.

If it does not smell, and shifts fine, leave it alone. Since it does not smell, then that means it's not burnt, so you should be fine.


----------



## robinhood4x4 (Apr 21, 2006)

Good site about the myths of tranny flushing.

http://www.gadgetonline.com/TransFlush.htm


----------



## snakebite (Apr 21, 2006)

i would change it thru the cooler lines pumping 2-3 gallons thru it.outlet into a jug and idle till you get bubbles.reconect and refill.drive a bit and repeat.
then drop pan/filter.
clean the magnet.if it looks like the science project with iron filings you got big trouble.
a little fine mud is ok.this is wear from the steels and normal.chunks or slivers of anything is bad.use only the spec of fluid the mfr recommends.i have done this to many auto trannies with nothing but improvement.i got over 300k miles out of a 200r4 before i had to rebuild it.only hard parts i had to replace were torque converter and stator support.
just dont try a flush to fix a problem and blame the flush when it dies anyway.
only 2 additives worth using in a trannie.
for cleanup-autorx.
when done with your fluid/filter swap as a last step add a bottle of lubrgard red.


----------



## cobb (Apr 27, 2006)

SHOOT!!!! I lost this post since I did part of what was suggested. 

I asked around and it seemed that the flushing machine was not suggested, too many cars are left dead in their tracks after the good crap was washed away from the innerds. 

Doing the filter was most recommended and the fluid in the pan, plus cleaning the pan. 

I decided at the least, the pan and filter. I got to see the history of the tranny and feel a bit more comfortable I have red vs brown fluid. The magnet thingie was coated in black slime, the bottom of the pan was covered in a grey powder, likely aluminum. THe filter opening looked clean and no plug thingie was found. 

I was going to undo the line and pump it out, but wanted to know the filter was clean and no crap in the pan. I was going to also drain the crap out of the torque converter, but it rained the whole time and nothing went right. THe jack was sunken into the ground, had to drag it across the yard. THe jack stands kept sinking in the ground and I was just nasty after laying on the ground. 

I ended up using high millage fluid. I thought about synth and regular. I did fine the mercron flavor, not mercron V or Mercron III. 

I think it runs better now after an hour of driving. Before it was rather muddy as to when it shifted midrange. Basically it seemed to get lost in gear selection at 25-35mph then it would grip again about that speed range and below it. Now its firm with a tap up to 35, then a slight depression of the gas petal is needed to go over 35. Not only can I spin on grass with a tap at idle, but I can kick up gravel from a dead stop to 15mph on the highway entrance path. Feels funny as what do I do at that point? Let off and loaf out into traffic or floor it, its already spinning, so I just wait for the noise to stop then give it more gas.


----------



## greenlight (Apr 27, 2006)

I listen to car talk, so I know all about fixing cars!

Dirty fluid is not an indication that it needs to be changed. All engine fluids get dirty.

Run it till it dies!!

Or let the next guy fix it.


----------



## colubrid (Apr 27, 2006)

I have heard the same thing from my mechanics friend about changing the oil on high miliage trannys. If you do put new oil in it will probably be the end of the tranny.


----------



## VWTim (Apr 27, 2006)

The slime on the magnet and dusting in the pan is normal, nothing to be worried about. As to flushes, barring pressure flushes, a basic tranny shop flush that taps into the cooler lines, I've done hundreds of those and NEVER a dead tranny in the shop or shortly thereafter. Good fluid is good fluid, broken down clutch material in the fluid is not the same as clutch material on the clutches.
Glad it's worked out for you. Might not be a bad idea to drain the torque converter one of these days too, get that fluid all clean.


----------



## SRMC (Apr 27, 2006)

colubrid said:


> I have heard the same thing from my mechanics friend about changing the oil on high miliage trannys. If you do put new oil in it will probably be the end of the tranny.



That was my experience. At 75K miles I had the fluid in my '98 sedan changed. Because of the design the filter could not be replaced, and it was basically a drain and refil. Within 10K miles the seals in the transmission were shot and it started overpressuring and blowing fluid out of the dipstick. I'm convinced that if I had left it alone it would have been fine. I had a similar experience after pushing new brake fluid through one of my cars. The wheel cylinders were scrubbed clean internally and started leaking immediately. I'd leave it alone.

SRMC


----------



## VWTim (Apr 28, 2006)

How do you know it was overpressurizing? Sounds like it was just heavily overfilled.

As to the brakes, the reason for the problems is most brakes aren't used thru their whole travel, and when the fluid gets neglected there can be coorosion and build up in areas the pistons don't normally travel. It wasn't the new fluid, it was the act of bleeding the brakes and moving the pistons thru travel they weren't used to that normally causes the problems. That's what preventative maintanance is for, prevent problems before they can show themselves.


----------



## cobb (Apr 29, 2006)

Well, we will see...... Its amazing the experience and sides you guys have to offer. 

I am ignorant about auto trannys, but I know some about engines. Its my experience engines like clean oil. Leavng dirty oil in your engine is the best way to get the rings to start passing oil and to wear away the surfaces of your bearings. Now, crap settled in your engine is ok, its dirty oil that causes problems. Ive know folks to flush their engine and get it to start buring oil or use synth oil and suddenly develop rod knock and put regular oil back in it and it stops knocking. 

The only problem I have with running dirty oil in the tranny is that there are bearings and seals that need clean oil and then you got the filter intake. 

Well, it seems to shift better and I put 4 hours in all on the new fluid. Not sure I will get 10 thousand miles on it. In a few weeks I should be legal to drive and going to hit the ground running. At least if I sell this soon, it had red tranny fluid, I ahve receipts from all the parts Ive bought and installed. Lets not gotget it as almost 3 grand below blue book.


----------



## springnr (Apr 29, 2006)

Tranny oil/fluid does not have to deal with combustion byproducts loading it up. Which is why transmission fluid is useable for a longer period of time than motor oil.

Heat will kill tranny fluid. Over time the additive pack wears out and normal tranny wear adds particles. So changing every 30K to 50K is good preventative maintenance. 

Do not over or under fill as this will cause problems. Some are meant to be checked with the tranny at operating temp while running others with engine off. 

Newer cars and trucks have computer to control the tranny so taking the battery cable off to reset the computer will let it reset to baseline and start learning again with the new fluid.


----------



## cobb (Jun 11, 2006)

I have to say since Ive done it, I agree with the side who says not to change it if its old, has a lot of miles on it, etc.


----------

