You will get answers from both sides. Change, don't change, flush, etc. IMHO, the best is to drop the pan, change the filter, add fluid, disconnect the cooler line, pump out about 3 quarts, add 3 quarts, pump, add, etc. until you have replaced all the old. That is what I will do soon with mine @ 105k miles. The sooner the better.

 

Winterbeater has got it down....

The ONLY thing to avoid is the "reverse flush", or using a solvent type "cleaner", BOTH of which have been known to cause issues that didn't previously exist in transmissions that didn't have changes when recommended....

Dropping the pan to clean out crud & replace filter is good...

getting more old fluid out by pumping it out through the cooler line works well...

knocking the crud loose & flushing it where it doesn't belong by reverse flushes or 'cleaning" solvents causes more problems than it solves in many cases....

luck!

 

The fluid when new is bright red. As it burns it turns orange then brown and will smell burnt. You can pull pan and then install drain plug, I did both of mine that way. Pan uses glue but there are gaskets now made that work well and seal much better.

I change my fluid maybe every 60-75K miles depending on color.

 

You can add a drain plug, or use this guy's method from the How-To located in our How-To Archive up there in the blue banner right under the thread name.

How to change automatic transmission fluid and filter

The only thing I don't agree with is starting the engine. I recommended he crank the engine to control fluid flow. If you start it, it literally takes like 5 seconds to pump all the fluid out. This will completely drain the fluid whereas draining simply the pan and dropping the pan to change the filter will only drain like 3-4 qts. With MerconV being $5/qt- it can get expensive to use this method. The only bonus is that it's much less messy. Partially unbolting the pan so you can drain fluid from a corner is tricky, and tends to be messy. Then the pan is still full of fluid. The pan will be full of fluid using this method as well- so be careful and take precautions to prevent spillage.

 

The only thing I don't agree with is starting the engine. I recommended he crank the engine to control fluid flow.

Good point. Is disconnecting the coil plug the best way to "crank without starting"?

 

I'm not sure where it's located, but on my old Taurus, I would disconnect the inertia switch.

Also, add a transmission cooler while you're at it.

 

Just do a conventional filter and fluid change, this process generally changes 30-40% of the fluid as the torque converter retains more than half of the transmission fluid capacity generally. Now if the vehicle sits for a period of a week or so, the converter will drain back into the pan and more of the fluid can be changed. So with the conventional method, the new fluid is diluted by the existing fluid. so if you really want to change all the fluid then change the filter once, and just do a drain and refill ever 20k miles and eventually all the fluid will be changed.

I agree with the above posters that caution against the use of chemical flushes.

 

probably

 

Better to yank fuel pump fuse or inertia plug to disable starting. Pump will try to flood motor with no ignition happening.

The so-called 3X fluid change. First time gets like 50% of fluid new, 2nd time 75%, and 3rd 87.5%, not much to be gained after that. You change the fluid in pan 3 times, expensive nowadays. I used to drive car 2 weeks between each change, also the reason behind installing drain plug, so no more pan removal.

I too have moved to just changing every 20-25K or so once. That keeps fluid in pretty good shape.

 

I have 160,000 miles on a 2006 auto transmission Focus. I have never changed the fluid but I want to because it is brown and not sweet-smelling. The transmission is strong and I try driving it without abusing the transmission. Should I change the fluid and filter?

 

Honestly I would talk to a dealer because I’ve talked to many shop and they say that the tranS get used to the fluid and changing it when over due it could hurt the transmission

 

This guys seems to have a done good job in terms of pulling out the remaining oil, that doesn't come out with taking the oil pan and filter out...

https://www.youtube.com/watch?v=AnFe8eSiJzc

 

Too late hugo24k, ALL ATX will seem 'strong' until the very day they fail. Why on earth people think you change oil in motor but not trans............well just stupid thinking there, no other way to put it and no insult intended. Then they've done the damage but want to change it then.

Better late than never but it may be too late.

 

Good post.

 

Doing the math....

If you can get 3 quarts out at a time of a 6.7 quart capacity:

Replacing 3 quarts at a time:

1) 3.7 quarts remain of 6.7 = 44.78%
2) 2.04 quarts remain of 6.7 = 69.5%
3) 1.13 quarts remain of 6.7 = 83.16%
4) .623 quarts remain of 6.7 = 90.7%
5) .344 quarts remain of 6.7 = 94.86% fluid changed

With a manual hand siphon pump at Harbor Freight, $10, a warmed up transmission and the car on ramps you can nearly fill a two liter Pepsi bottle one and a half times in less than 5 minutes.

Allow the new fluid added to mix with the old fluid, maybe a few days, and repeat to get the % changed you want. I use a more rigid clear oil resistant tube, on both ends of the pump, from HomeDepot instead of the soft orange tube that comes with the pump.

It will take 8 times if you only change 2 quarts at a time to get 94% changed, Opposed to 5 times if you can change 3 quarts at a time.

I change 3 quarts once maybe twice a year.

For the last 50k miles I've been using the high mileage Valvoline 'Max Life' fully synthetic ATF Mercon LV, 1 gallon for $14.

 

X2, and why I usually stopped at 3X and calling it the 3X fluid change. After that then just do a partial every 20-25K to keep much of it fresh, 100% of it does not have to be.

When doing my son's car, I even kept his 3X (4 quarts) and filtered it to reuse in my older car. Another $20 out of thin air there.

 

Good advice; Thanks !!!!!

 

Hi,

Does anybody know how many quart is full transmission and how many quart pan has with engine off? Focus 2001, automatic

 

You gotta read, I know it hurts, he just told you above.............................

 

Does fitting a drain plug require welding a nut on the inside? As surely the sump isnt thick enough just to tap into it. Is there a tutorial?

 

Seen it done that way, prob. the easiest & least likely to leak. Downside is less than complete draining countered by the ease of doing it more often.

Tutorial would be from welding info., and understanding easier ways to accomplish the task.

For example, using a bolt to hold the nut in position while doing the weld which also reduces problems from the thin material warping from heat. If the outside of the pan will be the sealing surface, leaving it unsupported during the welding makes it more likely to warp and not be a good sealing surface. Using that surface to seal makes weld porosity unimportant and only tack welds necessary as the Factory does with engine drain pans.

Welding a nut as a bung on the outside requires a perfect weld to seal it to the pan. This can be done, but requires more skill and would be easiest with better equipment like Tig welding.

 

I use bolt on drain plug setup with no welding at all. I mod the parts somewhat though to allow a bit more fluid to drain, you are limited by the thickness of the nut that remains inside the pan. Its' height determines how much fluid comes out.

Dorman/Motormite makes those plug setups.

I use copper gasket and replace their crap plug with an allen head 1/8" pipe plug to lower the amount the setup sticks out of pan bottom as it can hit things. The location you pick for hole drilled in pan figures in there big too.

 

I have a spare new m12 suzuki sv650 drain plug, i know a pro welder ill get him to weld the nut on the outside and will take pics and post in about 2wks... Thanks guys

 

They say that now to keep from getting blamed for owner refusing to spend money until they begin to slip. Any damage is already done long before you change the fluid too late. The only reason trans is still working is because the extra metal in the fluid makes it lock instead of the dead clutches.

Only the unlearned take one that far then wonder about it, you already tore it up.

 

What is a transmission cooler