transmission flush or just fluid change?

ok, again me...

I took on eof those free 21Plus trans checks blabla today, and they said, everythings fine, just the fluid is due for a change.

They said, when they would change it, they would drop the pan and stuff and get approx. 60% out off it and wouldn't recommend a flush, because the pressure might force little particles to get back onto the gears and stuff... (or something like that, don't rememeber exactly)

Is that B...sh... and he said it, because they don't have the machine to flush it, or should I really only drop the fluid out and have them put new stuff in??

what about filter change? I have heard that when they flush it, they flush the filter too, so it doesn't need to be changed... Sounds kinda weird to me!

I had mine flushed at the dealer and they told me the fluch would actually clear the filter out. I got it flushed first, then dropped the pan and changed the filter(just in case). A flush will get about 99% of the old fluid out. How many miles are on it, and have you ever changed the fluid or had it flushed. If you have high milage (90k-up), then I would not reccomend changing the fluid as it might ballon the seals and blow up.

I have done a flush on my truck personally. It runs at a low pressure, so there shouldn't be a problem with throwing particles back into the trans pan. Basically what a flush is, you fill the machine up with the new fluid and it sits in a sack. There is another sack on top of it and that is filled with the old fluid. Basically when the old is pushed out, the new fluid goes in. It took about 15-20 minutes to do my flush. If you have a lift on your truck and have big tires - I would recommend find some stock tires or some small tires to do it, since the rear wheels will be rotating and will most likely shake a lot. Flush is commonly looked at by other mechanics in our shop as the best way to go with doing a transmission service. Dropping the pan itself hardly gets the fluid out. Torque Converters are very "thirsty" and take up most of the fluid. I would recommend a flush and filter change. You should be good for another 60-70 thousand. Good luck.

-Drew

I just bought the car, so I don't know if there were some transmission services...

It has 102,000 miles!

You can do a flush in your driveway in about 15 min. This procedure will remove/replace almost all of the old fluid.

Good luck.....

Sorry, in the above post, I did not explain how to do the flush. Here it is.....

It is best to drop the pan ( at least once ) and change the filter, Refill with ATF of your choice and then do the following flush procedure:

I disconnected the "to transmission" hose from my remote filter housing. I plugged and clamped the disconnected line and added and hose clamped a 6 ft length of 3/8? line to the housing. The other end went into a calibrated water jug ( 1 gal size ).

The the truck run at idle while 1 quart is pumped out. Stop the truck andd add back 1 quart of new ATF.

We used 15 quarts of Amsoil ATF.

Even though this ATF ( Amsoil ) has about 40 k miles on it, it still looked remarkably good, just slightly darker in color.

After the flush/fill was completed, I added a new K & N filter to the housing and reattached the hoses.

The procedure took my son and I about 15 minutes to complete. There was no mess since we were well prepared for the flush; nary a drop was spilled.

If your rig has 80,000-100,000 miles on it and the filter & fluid has never been changed I recommend NOT to change it with a flush. Just change the filter & fluid that you lose when doing a filter change. Then do it again about every 3,000 to 5,000 miles until you see the fluid is now looking clear.
They gave you good advice. You just may open up a bees nest with a full flush!

old mechanic said:

They gave you good advice. You just may open up a bees nest with a full flush!

Click to expand...

With a power flush, this is true, however, by letting the tranny just pump out the old fluis as you add new, no harm is done and you get "almost" all of the fluid out.

thanks for the advice... Will probably do the change myself then!

I just crawled under the truck...

I could only find two lines (metal) going into the top/side of the trans! And they go into the radiator. One into the upper side and one down below!

Is this a trans fluid cooler inside of the radiator? ( I think I read about it!)

Through which one should I drain the fluid? and where exactly do I add the fluid?

thanks again

Do you have the factory external tranny coller? And, yes, there is a cooler in the radiator.

Unhook either line to the radiator, put some clear tubing over it and run it into a 5 gallon pail, preferably a white pail with graduations on it... get a long skinny funnel that fits into your dipstick tube and is easy to pour into and plan to add fluid thru the dipstick tube. Have some one at the ignition....open up all the bottles of new fluid and have them handy where you can reach them easily during this process. Start it up and as soon as fluid starts being pumped into the pail, try and add it thru the funnel in the dipstick tube opening at the same rate.. if you fall way behind (more than a couple quarts), stop the engine, and add until you catch up... keep at it until you see clear red fluid coming through the clear tubing (now you know know why it is clear tubing I suggested). This may take a quart or two more than the total fill capacity as some mixing occurs. When the fluid coming through the tubing is clear stop the engine, reconnect the fitting at the radiator, run the engine til warm and check your fluid level. It would be a good time to replace the filter too.(this entails removing the pan and making a mess - sorry. You might want to consider adding a drain plug to the pan while it's off. Easy enough to do.) By doing it this way you will have clean fluid through the trannie. You will pay for about 5 or 6 quarts more fluid than you actually need in the trannie (assuming you do a pan drop and replace the filter now as well) but it's a good way to do this process. (You can also do the pan drop and filter swap before the procedure, I just liked knowing the filter was new and clean and passing new and clean fluid right from it's installation.

I did this on my Explorer and a Sable a year or so ago and the fluid still looks new. (210,000 on the Explorer now and 110,000 on the Sable.)

And while there is some thought that power flushes on older trannies may not be a good idea, the notion that you should not change fluid on an old trannie at all... is NOT a good idea. A transmission needs clean fluid with the appropriate properties, at ANY age.

aldive said:

Do you have the factory external tranny coller? And, yes, there is a cooler in the radiator.

Click to expand...

did you mean factory external tranny cooler? or what is a coller? I mean the whole truck is stock. I don't think anybody changed something on it.

what size tubing should I get?

Bandido said:

did you mean factory external tranny cooler? or what is a coller? I mean the whole truck is stock. I don't think anybody changed something on it.

what size tubing should I get?

Click to expand...

Sorry, misstyping; I did mean the factory cooler. Bot all Explorers had the extra cooler; does yours?

I think mine has only the cooler inside the radiator... At least I can'f find anything else

Bandido said:

I think mine has only the cooler inside the radiator... At least I can'f find anything else

Click to expand...

The extra cooler is mounted in front of the radiator on the passenger side,

Oh, I found it. Yeah, I got that one.
So do I have this extra cooler and another one inside of the radiator??? Isn't that kinda non-smart engineering?

Now its very easy to flush using the rubber lines from the extra cooler.

thats a good idea!!! Will do that. And dropping the pan and change the filter I can do some other time...

One more thing: Do I have to use the Mercron fluid? You said something about amsoil ATF???

I am a firm believer in using full synthetic ATF and I do indeed use Amsoil ATF ( Dead Link Removed ).

A suggestion for you i s to add an external filter for that auto tranny; in addition to the extra filtration of the fluid, it also allows for wasy flushes and provides a mount for a tranny temp sensor. Take a look at the following thread: http://www.explorerforum.com/forums/showthread.php?t=34136&highlight=secondary+transmission+filter

Its a long thread but filled with great instalation information.

Good luck.....