I was gonna do a search, but the option is not available right now, so. I was thinking about changing the fluid in the tranny of my 89. I thinks it's AOD. Anyway I have heard that if you have not changed it regulary that it's not a good idea to do so. I'm not having any trouble with it now, but thought it might be a good idea to go ahead and change it. I would like to get some input from those of you that have done this. And I was thinking of maybe of going to a synthetic. I have 116,000 miles on it.

 

Here is a recent conversation about your subject: https://www.ford-trucks.com/dcforum/97up/2273.html

At this point in your transmission's life, I would stay away from synthetic fluid.

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'94 E-150 Conversion Van 4.9 / C-6 -- '89 Mustang LX 5.0

 

Changing my tranny fluid at 85k miles got rid of several problems, and no, I wouldn't go with a synthetic. Just make sure you use what Ford calls for. Probably merconIII

 

In that post mentioned above, the guy said the Transmission is a "closed system"? Could have fooled me! I drove down to the Missouri river levee on a camping trip in Sibley, MO about two months ago, and slopped down a muddy road. On the way home, my AODE tranny LOCKED into THIRD gear. I got home, loosened the pan, and drained about 3 gallons of water out of my TRANSMISSION! Checked the filler tube seal, good. Checked the coolant lines, good. No loss of anti-freeze from the radiator, either. Fluid smelled badly burnt. I wasn't leaking tranny fluid from anywhere. Thinking I had fried my 4th tranny in two years, I waited a month and a half before getting bored and pulling the pan all the way off. At the bottom was about a half inch thick layer of mud, sand, silt, etc...Anyways, New filter, gasket, and fluid, and the tranny (for now) works fine..Almost gave me a heart attack when i dropped the pan though! Maybe it was a freak occurance, and my truck spazzed out thinking it was a Chevy or something....Who knows...

Note on actual subject:
I'm at 86000 miles on a 1995 f-150 4x4, AODE, 5 fluid changes (I'm very protective) and nothing negative has ever come from changing it.

 

I read both this post and the linked-to post; I've worked at a quickie-lube place, and now work for an independant garage, and I'll say this: I'd change the fluid if I were you.

The reason shops don't want to change higher-mileage transmission fluids is because of the headache that occurs when such a transmission does fall apart. Generally garages don't judge the change/won't change transmissions by mileages on the tranny but actually by how bad the fluid looks. If the fluid looks beyond brown & burnt (like the fluid is nearly a 'solid', or it is completely opaque), most shops will not want to change it because, often enough, these trannies will go bad in short order after changing the fluid. No-one has ever told me why it happens, but once the fluid gets that bad the trannies have a reputation of lasting a little longer with the crappy old stuff in it.

I doubt yours is that bad, and even if it was I would still take the chance on changing the fluid out and putting a high quality fluid in (a tranny shop once put Amoco trans fluid in one of my trannies, and that stuff was terrible - i would suggest a major oil manufacturer, or I really love the shifts I get with synthetics - transmissions (and the differentials - essentially the drivetrain) are actually the place a driver would notice a synthetic in as far as driveability).

To sum it up, if a shop recommends you not change it without looking at the fluid, that's bad. But shops are trying to protect themselves and reduce the amounts of come-back headaches they get, and reduce their liability if someone claims their tranny went south after being serviced by them. They'd like to do nothing more than take your money, but not if there is a big chance of it causing them a problem later.
No matter what, the fluid still ought to be changed. Even if the owner has a severe case of opaqe tranny fluid, they ought to take the chance on changing it out - the only problem is that a shop may not want to do the work, so it now becomes a driveway-job for the owner to take care of.
Lastly, always use quality lubricants - ask what brand the tranny shop is going to use.

Best,

 

GammaDriver

>If the fluid looks beyond brown & burnt (like the
>fluid is nearly a 'solid', or it is completely opaque), most
>shops will not want to change it because, often enough,
>these trannies will go bad in short order after changing the
>fluid. No-one has ever told me why it happens, but once the
>fluid gets that bad the trannies have a reputation of
>lasting a little longer with the crappy old stuff in it.

In my post on the other board, my statement below should answer your question. This answer is the result of my past experience as a manager for a transmission shop. Although an older transmission is not going to fail every time, this is usually the cause....

"Transmission fluid has a very high detergent level. If your old fluid is really bad, the new fluid will clean out all the old build-up around the seals and gaskets and may soon start to leak. Particles of this build-up now floating around could get into the valve body and cause shifting problems. The new fluid will react with the old brittle clutch material and cause them to flake."

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'94 E-150 Conversion Van 4.9 / C-6 -- '89 Mustang LX 5.0

 

How do you actually "flush" a tranny? I'd like to change the fluid, but I would like to try and be sure I don't have any of them "floaters" in there, LOL!

 

8996EBBroncos

Usually, if you drain the fluid while it's hot, the "floaters" will come out with the fluid and should be quite sufficient. There are places that will do a power flush, but they're pretty expensive from what I've heard.

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'94 E-150 Conversion Van 4.9 / C-6 -- '89 Mustang LX 5.0

 

Thanks for the tips, 94 and others. I'ma check around about the flushing deal.

 

I did a search on google and came up with this, I'm not done searching yet. But I thought that this was a pretty good way to flush the tranny.

While it's much better for the transmission to change the fluid using the method in [the above] article than it is not to change the fluid at all, this method only replaces about half of the fluid in the transmission. The best thing to do is to change out ALL of the fluid, and this is also something a person can do themselves.

First, drain the fluid from the pan, just like you would using Mr. Macfairlane's procedure. Once you've replaced the filter, the pan gasket, and reinstalled the pan, you're ready for the next step.

Fill the transmission to the proper level using the proper type of transmission fluid. Then disconnect the return transmission line (the line in which transmission fluid flows from the transmission cooler back to the transmission), located near the bottom of the radiator. There's two transmission lines connected in this location, and the bottom line is usually the return line. Once the line has been disconnected, attach a clear piece of tubing to the transmission cooler, the same diameter as the transmission line, approximately 5-6 feet long, using the transmission line clamp to secure it.

Place the unattached end of the clear tube in a plastic, one gallon milk container and place it where it can be seen (like not under the car).

For the next portion of the procedure, make sure that the parking brake is set prior to continuing. Start the engine. The transmission may have to be put into "Neutral" or "Drive" in order to pump the fluid from the transmission. I usually put mine in "Neutral" to accomplish this step. While the transmission is pumping out fluid, you can monitor approximately how much fluid has been pumped out by looking at how much fluid has been pumped into the plastic milk jug. While fluid is being pumped out, slowly add new fluid to the transmission at about the same rate as its being pumped out. This keeps the fluid level at, or near the proper level. You can see the condition of the fluid through the clear tubing as its being pumped out.

After approximately 4 to 5 quarts (obviously, if it's more than 4 quarts, you'll have to turn of the engine, and fetch another milk jug) of fluid have been pumped out, you should notice a change in the color of the fluid. It should go from a brownish red color, to a bright pinkish red color. When this happens, all of the old fluid has been replaced with new fluid.

Be careful not to overfill the tranny during this procedure.

When completed, reconnect the transmission return line to the transmission cooler. Check the fluid level as you normally would, and add fluid as required.

This fluid change method is twice as good for your transmission as the method of only changing out half of the fluid is. Happy shifting!