Automatic Transmissions...A General Question

[Nitekruizer]

If there's one part of a vehicle that I don't know very much about it has to be the automatic transmission. One thing that I do know though is that I seem to go through them faster than a baby goes through diapers!
I don't know if it's my fault or if they are just failing on their own. So I have a couple of generic questions about them. Not just classic car/truck transmissions like the Ford C4's, C6's and FMX's, Mopar 727's, ect., but also the newer electronic controlled transmissions.
1. Does it hurt an automatic to drive it slowly in DRIVE for twenty or thirty minutes at a time? I mean, of course, with the engine at normal temperatures, engine not overheating. For example, driving in rush hour city traffic at speeds of 10, 12 or 15 mph? Frequent stops, but not driving it hard.
2. Could it damage a transmission to "top up" the fluid with a "Multi-Vehicle" type store brand fluid even if no more than 5 or 6 ounces of fluid were added and the transmission was not overfilled?
Thanks in advance

[Donnie]

Hi, what trannies are failing on you? One cause of repeat failure's is the cooler & the cooler lines are contaminated with metal & friction material from the previous failure....The cooler MUST be flushed or replaced........before installing a replacement unit. Blowing air thru the lines WILL NOT clean them......The air just passes over "whatever".........Flushing is a MUST DO>

Part 1 : driving as you described will not hurt your unit

Part 2 : I am going to not commit this one........you will get a few different opinion's, I'm sure...............Donnie

[ultraranger]

"... I don't know if it's my fault or if they are just failing on their own. So I have a couple of generic questions about them. Not just classic car/truck transmissions like the Ford C4's, C6's and FMX's, Mopar 727's, ect., but also the newer electronic controlled transmissions...

1. Does it hurt an automatic to drive it slowly in DRIVE for twenty or thirty minutes at a time? I mean, of course, with the engine at normal temperatures, engine not overheating. For example, driving in rush hour city traffic at speeds of 10, 12 or 15 mph? Frequent stops, but not driving it hard.
2. Could it damage a transmission to "top up" the fluid with a "Multi-Vehicle" type store brand fluid even if no more than 5 or 6 ounces of fluid were added and the transmission was not overfilled?
Thanks in advance"

Ford C-4/C-6 specifies Type-F transmission fluid. If you are using/adding anything else, you are probably asking for trouble.

In reference to the "newer electronic controlled transmissions," I haven't gone through the transmission and installed it in my '69 Ranger yet but, I have a Ford 4R70W electronically-shifted 4-speed overdrive transmission I pulled from a 1998 3.8L Mustang. Many people seem to have a fear of anything electronic but the 4R70W is one of the very best automatic transmissions ever built by Ford.

My (1998 3.8L V6 Mustang) 4R70W transmission just after I got home with it from the wrecking yard. I gave $138.00 dollars for this from U-Pull-It in Little Rock, Arkansas, which included; the transmission, torque converter, block plate, wiring harness, dipstick & tube.



...after I pressure washed the 4R70W to get the grime off of it.






The 4R70W is an evolutionary advancement of the old 1980-1994 Ford AOD. The 4R70W can easily handle over 600 hp and only requires a stand-alone shift controller, such as the Quick 1 from U.S. Shift.com (Formerly Baumann Electronic Controls) http://usshift.com/ --which will work with either a carbureted or fuel injected engine. The shift controller is also programmable so you can tailor the shift curve/firmness of the transmission's shifts right from the controller.

1. http://www.becontrols.com/aode.htm

2. http://usshift.com/downloads/4R70Wmanual.pdf

3. http://www.tccoa.com/articles/tranny/transmission/

[Nitekruizer]

Donnie, thank you for the quick response.
One transmission that I'm repeatedly having problems with is the FMX. I'm begining to wonder if anybody knows how to rebuild them. I've gone through several of them. A couple of them were auto wrecker transmissions, so, I guess that's to be expected. Three of them were rebuilt by transmission shops. Of the three that were professionally rebuilt, two of them were installed by the shops and one of them I installed myself. Strangely, the one that I installed lasted longer than the two that were installed by the transmission shops.
The last transmission was one that I bought from an auto wrecker. I replaced the input and output shaft seals and gave it a new filter and fluid when installing it. It died in just two weeks. I removed it and it sat in my garage for over a year while I used another transmission. When that one failed, I took the one in the garage to a reputable shop to have it rebuilt. That way I could still drive my car to work for a few days while they were rebuilding the other transmission. The plan was to just drive to the shop when it was ready and they would swap them.
Everything went according to plan except that when they were replacing/swapping the trannies they decided to replace the ring gear. The ring gear they installed turned out to be the wrong one and they "crushed the pump" when they tried to bolt the transmission to the engine. They had to take the transmission apart to fix it. They do have a machine for flushing coolers and lines, but I don't know if they would have used it, or if they would have needed to, when they re-installed the transmission. This transmission didn't last very long.
I stopped driving that car for now and bought a different car to use as my daily driver. I've been driving it for a year and a half. A few days ago I noticed the burnt smell of transmission, a smell I know all too well now, while I was driving it. This is the car that I had added the "Multi-Vehicle" ATF to. It says on the bottle that the fluid is "recommended for use in most North American vehicles". This car has what I believe to be a 41TE Chrysler electronic controlled automatic transaxle.

[Nitekruizer]

Thank you, ultraranger. I have been thinking about giving up on FMX's altogether and using something else. I was thinking about a C6 or possibly an AOD from an early '90's truck. My engine is a 351W and I haven't checked to see how common the C6's were for small blocks. The 4R70W is a transmission that I didn't know about, but it sounds promising as a possible replacement.

[motzingg]

sounds like you are dealing with an incompetent shop to me...

what exactly happens when these 'die'? an auto trans isn't a magic box, its just a mechanical device that is governed by the same laws as anything else. do they stop engaging? stop shifting? stick in one gear? generally speaking even using drastically wrong fluid wont kill an auto trans completely, but will cause it to wear out fast or act wacky.

another thing to consider is a floating ground in your car that is causing electrical current to flow in the wrong places. its a fairly common problem for cars of the 'early electronic control' era (early-mid 90's) to start showing up with ground fault issues, too much resistance in a ground circuit can cause solenoids to burn out or overheat, or not have enough power to make a good shift. sensors can run off of milli volt or amp signals that a little corrosion in a connector, wire, or ground screw can throw all out of whack.

a company called ATSG https://www.atsg.us/atsg/ sells aftermarket manuals for automatic trans repair, they are about 25 bucks and well worth it. You will get test procedures and tolerance levels, breakdown drawings, and more information than you can shake a stick at. If you know what you are doing and read their manual you will probably know more than your crappy trans shop technicians in about 3 hours.

here this is the one for your car
https://www.atsg.us/atsg/a604-41te-1.html

[ultraranger]

As Motzingg suggests, ATSG does have some good info in their transmission service/rebuild publications, for specific transmissions.

These are the two ATSG manuals I have for when I rebuild my 4R70W; https://www.atsg.us/atsg/ford-manuals-1/aode-4r70w.html & https://www.atsg.us/atsg/ford-manuals-1 ... dbook.html

An even better manual(s) I have are actual Ford service department manuals for rebuilding my 4R70W. I got both of these off Ebay for under $40 bucks for the pair. It goes into much more detail than the ATSG manuals so, you may consider that route if you are interested in getting an actual dealer service manual for whatever transmission you will be dealing with .

[Donnie]

Nitekruizer, I agree with Motzing on this one........The Iron case COM is EASY to rebuild. But, you will need to find a shop with an older tech that understands this unit...It uses a Ravigneaux gear train which is not the same as a Simpson gear train that is used in C4's--C6's--727---904's and others....It was designed by a French engineer around 1950.....Ford has been using this set up for 60 years, with minor changes in the AOD,
AODE, & the 4R70W....still many techs do not under stand how this gear set works........they just replace it if they see a fault, chipped gear etc.
Understanding this unit is a bit more complicated, But it is a good design, just more costly to replace as it is all in one housing. Simpson uses 2 planet's...Replace only 1 if it is bad.
You can also use either type F or Dex in your C4 or C6.........Dex is a bit more slippery & will give you softer shifts..Dex/ Mer. is called " fluid modified" that is what it means........When Lincoln owners started to complain years ago about firm shifts, Ford started using Dex.
Type F will grab just a slight bit better for a more positive shift.........either will work, your preference

Honda for one likes to use their own fluid.......I have seen Honda's fail because of improper fluid. Your 604 also does well on 7176 fluid. What year & bodystyle is your Mopar?
Does it ever feel like it is stuck in 2nd gear? What engine size? How many miles?

Also on your COM's...whose converter were you using?........there is a lot of junk out there.........Donnie

[Nitekruizer]

Thanks again guys for all of your responses and information.

[Nitekruizer]

You can also use either type F or Dex in your C4 or C6.........Dex is a bit more slippery & will give you softer shifts..Dex/ Mer. is called " fluid modified" that is what it means........When Lincoln owners started to complain years ago about firm shifts, Ford started using Dex.
Type F will grab just a slight bit better for a more positive shift.........either will work, your preference



Also on your COM's...whose converter were you using?........there is a lot of junk out there.........Donnie

I was wondering about the fluid. Since the C4 and C6 can use Dexron, is it okay to use Dexron in the FMX too? The only two FMX's that I still have have these tags attached. One transmission is PHB-L8 and the other one is PHB-AT2.
I don't know what torque converters these are. They were supplied by the transmission shops.

[Nitekruizer]

Honda for one likes to use their own fluid.......I have seen Honda's fail because of improper fluid. Your 604 also does well on 7176 fluid. What year & bodystyle is your Mopar?
Does it ever feel like it is stuck in 2nd gear? What engine size? How many miles?

.........Donnie

Donnie, I've done a bit more research and it turns out that my trans may be a 40TE not a 41TE. I'm still trying to i.d. it for sure. Apparently, they started using the 40TE one year before my car was made. My car is a 2005 Sebring sedan with the 2.4L DOHC. The odometer is showing 303,000 km. The car seems to have been well cared for and is in really nice shape except for a few stone chips in the paint. I've owned it for a year and a half. The PO said that she had owned it for a year.
I looked at the bottle of "Multi-Vehicle ATF" that I had added to my Sebring and it does say in the fine print that it's compatible with ATF+4. I also noticed that I only used 4 ounces out of the bottle.
No, the trans has never stayed in second and really hasn't acted up at all except that I think the shifts are getting softer and there definitely is a burnt clutch smell.
This is the same way that my FMX's fail. They start to put off the burnt smell. They start to slip, that is, I have to put my foot progressivly further and further into the gas to accelerate or climb a hill. The engine revs higher than normal to climb a hill while the car loses speed at the same time. Eventually they don't even want to pull themselves up the little hill into my driveway.

[Donnie]

Now that I see you are driving a "604" these tranny's are totally unlike your COM's......in 1989 Chry was the first computer controlled SMART trans.
Not only does it not have any bands, it has 5 clutch packs & is totally controlled by a processor (computer)...The computer reads about 6 inputs from sensors throughout the car & tells the trans when to shift & how firm...It will, if working properly, adapt to your driving habits.
It also has the ability to compensate for worn clutches by monitoring the time that a unit takes to apply & changing the time/ amount of fluid to apply said clutch..===a worn clutch can feel normal again...the service engine light will come on if a fault is detected to warn you that a problem is happening....This sets a code in the computer that is available to any tech with a scan tool & will remain there for a certain # of engine starts, so you have time to get to a shop. If your light is coming on, I would have a GOOD trans shop scan it...On this trans, myself, I would only use 7176 fluid....others may disagree, but I've had TOOO many failed units that have had their fluid changed by unknowing folks..If this trans feels a firm shift due to improper fluid, it will try to compensate by controlling the solenoids to soften the shifts....This trans has no modulator to read engine vacuum, no cable or rod to feel the throttle position.Everything is controlled by sensor inputs, processed and a command is sent to the transmission...I doubt that 4 oz of other fluid caused your problem...but if you suspect that Dex or Mercon is the fluid in your trans, I would change it.....after thought.......7176 is MORE slippery than Dex.....& type F
ALSO THE MAIN CAUSE OF FAILURE IN THIS TRANS IS THE FRONT BEARING IN THE TORQUE CONVERTER, the after mkt came out with a washer to replace this bearing a few years ago, AND THEN Chry finally caught on & now uses a washer in the converter...A LOT LESS 604's needing repair
I'm not sure what year CHRY made the change,,,,,,around mid 2000's , just not sure of the year........all for now.......Donnie
There is probably a lot of stuff on line about Chry fluid, do more research....good luck

[Nitekruizer]

The engine light isn't on and there are no codes...yet. I'll try changing the filter and filling it with the right fluid.
Thanks again everyone.

[Donnie]

There should be a magnet in your pan, if it looks like velvet, that is normal wear, from all the planetary gears, if it looks like a Christmas tree, larger shards of metal a failure is possibly in your future....The magnet will tell a lot............Donnie