Automatic transmission fluid compatibility

Hello Johnjohn,

My Tribologist says the ATF+4 is synthetic so it may or may not work. Any moisture may cause curding and the additive package in the Dextron is likely not strong enough. Mercon will have the same issues possibly worse.

I use Hy-Torque in all my automatics (GM, Ford and Dodge) and as far as I know was the first to use it in a Ford automatic transmission (C6) the band were burnt and I had 10 gallons of free to use.

It's not cheap but I've gotten an extra 100,000 miles out of burnt bands in both Ford and Oldsmobile automatics using Hy-Torque. It also runs much cooler.

To change fluids you will want to flush the old out with new and drain then refill. some Torque converters have a drain plug that helps get the old out. Have no idea about your's.

Sorry what I have is opinion and no easy cure.

Brad

John,

You could always drain the pan then refill, disconnect the line going to the cooler.

Run the engine until about a quart comes out, add a new quart... continue until you see the color change for the new fluid.

2 man job.

Chaz

Mixing new fluid with old means that you are still using some older contaminated fluids. Your transmission is worth more than that to protect it and should be refilled with new fluids only. I had a GM transmission without a drain plug and clutches banging every time I started off and was told I needed a new transmission until someone said the fluid level was probably low. I warmed the system up, drilled a hole about 1/8 inch in the bottom of the transmission and drained all the old fluid out, running the engine for about 10 minutes to spin all the last of the fluid out of the system and left to drain overnight. The hole was plugged with a self tapping screw sealed to stop leaks. To fill the system the workshop manual says the engine has to be run to ensure it was correctly full. Measuring the difference to the drained fluid showed that about 2 litres had leaked out of the transmission.

How much does a drain facility cost to put in per vehicle? Well, simplifyied; an extra instruction on the software, a few seconds time on the machine line, extra wear on drill and tap, extra plug, seal and fitting time, divided by number of boxes manufactured. Result - peanuts. Perhaps GM don't like the word extra.

This looks like GM are trying to be too clever in not incorporating drain plugs. It sounds good to say you don't need to replace the fluids but that assumes nothing ever leaks or needs replacing. And running the engine while filling the box up? Come on, thats a bit dangerous isn't it?

There is a possible alternative. A company called International Lubricants (www.lubegard.com) makes special additives which can chemically modify certain types of lubricants, including ATF for other applications.

They offer a product which they state will modify Dexron/Mercon ATF for Chrysler/Dodge ATF+4 usage.

I have not used this particular product, so I cannot testify as to its effectiveness. However, I worked as a dealer and independent auto service technician for 12 years before I earned my engineering degree and left the auto field, but I used a variety of their products and they all worked well, including the ATF modifiers that I did use.

It may be worth your time to look into this product.

Hi standarded,

Thanks for the link. Looks like Lubegard HFM (Highly Friction Modified) is what I need. According the their website HFM converts Dexron into a compatible ATF+4 blend.

I think I'll look into this a little more. Sounds like just what I need.

Also, thanks to all for your input.

-John

Greetings.

Refer to thread " why does transmission fluid overheat"

I have 1992 Dodge Dakota v8 4wd and I use Amsoil. Bought Dakota at 119,000 miles and it just turned 213,000 now 11 years later.

The eaisest way and likely the cheapest way to change the fluid properly, including the fluid in your convertor is to take it into a shop, Zip Lube, jiffy Lube, or your personal mechanic if they have the proper equipment. They can flush the old fluid with new fluid without dropping the pan, if you trust the filter.

Make sure that they know you are removing the GM fluid so they are more vigilant in removing all of the old fluid. You are supposed to alternate between full flushes and dropping the pan and changing filters anyway or you never will get completely clean fluid.

It worked well for 40,000 miles you say. I say if it worked well for almost two trips around the world at the equator, use the same oil. "why mess with it if it works?" (that's my grandpa's famous saying).

Wangito

Your Dodge dealer will more than likely have a system that will FLUSH out your old trans fluid and that also flushes the torque converter. The equipment is usually supplier by a third party company that has them sell their additives(BG is one). I have seen it done several times. Since yours was just done 40k ago it should work great. I have seen in several cases if the vehicle trans fluid was neglected, the new fluid has a detergent to it and it cleans the varnish and sludge off. Then you have Trans problems.

Word of caution here. Careful on the flushes. Some service centers will "sell" you on the clean and flush. Older transmissions may not respond well to the treatment. A friend of mine "bought" the service and within a couple of weeks started experiencing increasingly more and more odd behaviors to the point that the transmission would no longer propel the car over 35 mph. This was a '92 Ford Escort wagon with about 120K miles. Ran fine before the service. Coincidence? Maybe, maybe not.

Automatic transmissions are the greatest wonder of the technological age....they normally outlast everything else.

Drop the pan. Its not that hard! There will be a half centimeter layer of dirt and metal filings in the bottom...this is normal. Clean it out, replace the filter. Use a new gasket, put it all back together. Replace with the same fluid as was in there before..it worked this long, it'll work that long again. Only after that process is done should you think about flushing the system. A system flush does not equal, replace, or obviate a tranny service. Flushing stirs up the gunk on the bottom, and will end up doing more harm than good if you don't clean out the pan first.

If you have burnt tranny oil, then take it to the pros for a band adjustment. They will do all the above as well as bringing your transmission into spec. You should notice that when you go to check your oil. Catch these problems early, and the fix will be cheap.

(Need I mention that you always check the transmission oil by starting the engine, cyclling it into forward and reverse, then leaving it in "park" as you check the level? Don't over fill....and pay attention to the "hot" and "cold" oil levels. Failing to do it this way will leave you with a false indication of fluid level...and you know that is not good. The stories I could tell!!!!)

Thanks Yusef1,

Your comments are duly noted and appreciated.

-John

Also Johnjohn,

You may know to but I haven't seen it mentioned, smell the tranny oil, if burn you will be able to smell it before you can see it.

Adjusting bands is not hard if you have a good manual.

Over 310K on my pickup and will put another 500 on it next weekend.

Brad

Thanks again to all.

I talked with my local Dodge dealer today and they charge $159.00 for a Tranny flush which includes new filter, ATF+4 fluid and Dodge approved additives.

I think I'll take them up on it. What'ya think guys?

-John

I was going to mention to get it flushed and use the recommended fluid. You may find a reputable transmission shop/garage that will do it for a little less but considering it's a dealer, $159 ain't bad. I get mine done for about $80 but it's a Toyota Tacoma. Probably doesn't take quite as much or use ATF+4 and that's why it's a little cheaper.

I think it would be cheaper than replacing a shelled-out tranny a thousand miles away from home...

Just put a new one in the Dodge Diesel(electrical issues) $4300.00 installed. Over 200k miles and the brain goes out of it.

Brad

I would say "Go ahead and go for it!!"... Get ALL the Dexron out of there, and ATF+4 in. I lost a Dodge transmission once because in a rush (and my innocence) I told the clerk "Gimme some ATF"... which he did.

Once you do have it full of ATF+4, I would feel safe changing it about every 70K miles (check the manual on this) just by removing the pan (about 10 qty screws with 10 mm hex heads in the Dodge Caravan) and ignore what is in the torque converter. Be sure to look for a magnet in the pan which will need to be cleaned also.

Now my experience is with the Caravan only. Your truck might be different from this.

Ah for the olden days when we used "ATF" and if this was not available, we could get away with 5w engine oil... but that was a long time ago.

Sincerely

Bill

I used to manage a chain of quick change oil shops in a previous life. Dodge/chrysler vehicles call for ATF+4. ATF+4 is a full synthetic. Originally your vehicle had ATF+3 in it. ATF+3 was a conventional transmission fluid. ATF+4 replaced the +3 fluid spec. The shop manual said it was ok to top off a low transmission with Dexron/Mercon fluid but not to change it completely out. I would assume a top off would mean 1 qt or less.

You need to change the fluid and refill with ATF+4. Dexron/Mercon is not going to be as good for the transmission as what is called for by Dodge.

I own a 1998 Dodge 3/4 ton V10 with 160,000 miles on it. I use a hand pump and run the hose down the dip stick tube and pump as much fluid as I can out. I usually get about 4 qts out this way. I do that about every 15,000 miles. Every 30,000 miles I drop the pan and change the pan gasket and filter. I abuse my truck by towing a large camp trailer, hauling heavy loads and off road driving. Dodge trucks in the 90's had a reputation for transmission troubles. I haven't had any trouble with mine.

When the Dexron fluid was installed in your truck they didn't get all of the fluid out either so you are running a mixture of Dexron and ATF+3 or 4. If I were you I would get a hand pump and do what I did on my truck and pump out as much fluid as you can through the dipstick tube. Refill the trans with the correct fluid. Start the engine and run through the gears a few times. Repeat this step at least 1 more time but preferably 2 times. Drive the truck around town for a few miles. Bring it back home and drop the pan and change the pan gasket, filter and refill with the correct fluid to the correct fluid level on the stick. Your transmission will hold 10-14 qts of fluid depending on what transmission is in your truck. You are good to go. In 10,000 miles I would change the fluid and filter again then start a routine changing the fluid/filter every 30,000 miles. Every 15,000 miles I would pump out what I could through the dipstick. Also note that on Mopar/Dodge vehicles you check most of them while idling in Neutral not Park. Read your dipstick it will tell to check in Neutral. You should get good service from your truck if you do this.

Regards,

John

Hi all,

My Dodge dealer flushed it today. I now have all ATF+4 fluid and feel good about traveling cross country.

Thanks to all,

-John