Comparing Mercon V, ATF+3, ATF+4 specs

[FazerZ]

Speaking as a transmission builder, I can say that using ATF +3 or ATF +4 in any DCX automatic transaxle or transmission will work just fine.

Most DCX transaxles will work just as good with quality dexron III, but in some instances, the TCC apply/release will not be good enough and cause complaints.

The advent of duty-controlled torque convertor lockup clutches and SLOWWW apply rates have brought about the need for highly friction modified fluids to eliminate NVH and durability concerns.

This is where the FM fluids, all the manufacturers are moving toward, have the greatest effect: TCC apply/release.

The use of ATF +3 or +4 depends on what you are trying to accomplish.

Service intervals are the key. G-man is correct in assuming if you use ATF +3, you will have to increase your fluid change intervals, because the fluid will not hold up as long and break down as ATF +4.

ATF +4 will allow for extended service intervals and likely give you the best performance (at an additional $).

We have moved all our builds and services over to ATF +4 for all DCX vehicles to consolidate fluid types, increase recommended service intervals, and reduce in-warranty concerns.

The last comment is about the durability of the DCX units, specifically the 41TE, 42LE (A604,A606) and fluid use. These units fail because of excessive cost-cutting and poor quality parts. The transaxle design was hands down the most advanced when they were introduced, but they were plagued with part QC. Even now, other manfacturers are just introducing the same/similar design ideas that chrysler had in 89.

If they would have just spent more money on making stronger/more durable parts (which they are slowly doing now)

DH

 

[G-MAN]

quote:

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Originally posted by FazerZ:
Service intervals are the key. G-man is correct in assuming if you use ATF +3, you will have to increase your fluid change intervals, because the fluid will not hold up as long and break down as ATF +4.

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Exactly. Since my plan henceforth is to pump the pan dry every year and refill with 5 quarts of XOM ATF+3, I'm quite sure this fluid will give my transmission just as long a service life as leaving the ATF+4 "fill for life" fluid in there without changing it.

I have observed absolutely NO difference in the performance of my transmission or its shift quality since putting in the XOM ATF+3.

 

[99]

Get back to us in a year or so and give us the details. I'd like to see what happens. Like I said, you are the only person that I've heard of that has went backwards.

And as for leaving the +4 in for life? LOL. No ATF is lifetime. VW says the same thing and I don't buy it. Those of us VW'ers out there that have changed our ATF know better than to believe it. Anyways, if I ran +4 I would still change it out yearly, just like I do with my +3.

 

[TooSlick]

If you note how close these are in terms of viscometrics, you can see how Amsoil is able to cover these three applications with one fluid - once they were able to tailor in the correct friction retention properties using several types of "selective" friction modifiers.

Amsoil synthetic ATF:

Vis @ 100C, 7.5 cst
Vis @ 40C, 37.2 cst
VI, 172
Noack Volatility, 10.1%
Four Ball (req for Mercon V), 0.40 mm
Flash Point, +435F
Pour Point , -61F
Brookfield @ -20C, 1342 Cp
Brookfield @ -40C, 9620 Cp

Note that PC is recommending Mercon V for all the older Mercon applications as well - no surprise there if you compare the Mercon V and Mercon requirements. These Petro Canada fluids are no doubt made with their excellent Group III basestocks. The Amsoil ATF is a PAO based product....

Tooslick

 

[RF Overlord]

quote:

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Originally posted by TooSlick:
Note that PC is recommending Mercon V for all the older Mercon applications as well

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I have a problem with Petro-Canada's recommendation...Jerry Wroblewski, one of the designers of the Ford 4R70W transmission, has said that although it's acceptable to use Mercon V in place of Mercon in all older-model AODE and 4R70W transmissions, DON'T use Mercon V in any OTHER Ford transmission or transaxle that didn't originally call for it.

 

[G-MAN]

quote:

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Originally posted by FazerZ:
The last comment is about the durability of the DCX units, specifically the 41TE, 42LE (A604,A606) and fluid use. These units fail because of excessive cost-cutting and poor quality parts. The transaxle design was hands down the most advanced when they were introduced, but they were plagued with part QC. Even now, other manfacturers are just introducing the same/similar design ideas that chrysler had in 89.

If they would have just spent more money on making stronger/more durable parts (which they are slowly doing now)

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I'm pretty sure Chrysler had more or less addressed the QC problems these transaxles had from being rushed into production by the time the first generation LH cars came out in 1992. The vast majority of problems with A604/A606 family after that came from the use of poor quality fluid and/or the wrong fluid.

 

[FazerZ]

quote:

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I'm pretty sure Chrysler had more or less addressed the QC problems these transaxles had from being rushed into production by the time the first generation LH cars came out in 1992. The vast majority of problems with A604/A606 family after that came from the use of poor quality fluid and/or the wrong fluid.

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I don't know what you are basing this statement on. Fluid quality or type did NOT contribute to the widespread failures of these units.

Can you specific talk about why you think this?

DH

 

[G-MAN]

quote:

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Originally posted by FazerZ:
I don't know what you are basing this statement on. Fluid quality or type did NOT contribute to the widespread failures of these units.

Can you specific talk about why you think this?

DH

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I'm not talking about flat out failures. I'm talking about issues of poor shift quality and shudder only.

 

[G-MAN]

quote:

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Originally posted by FazerZ:

quote:

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I'm pretty sure Chrysler had more or less addressed the QC problems these transaxles had from being rushed into production by the time the first generation LH cars came out in 1992. The vast majority of problems with A604/A606 family after that came from the use of poor quality fluid and/or the wrong fluid.

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I don't know what you are basing this statement on. Fluid quality or type did NOT contribute to the widespread failures of these units.

Can you specific talk about why you think this?

DH

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Here is the quote from allpar.com I had in the back of my head when I wrote that:

quote:

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Jim, the owner of Gene Poon's transmission shop, died of cancer. Jim knew his customers, and had so much of their trust that customers would ask him advice on what new cars to buy. When Gene bought his used Intrepid, he first asked Jim about the status of the 604/Ultradrive. Jim assured him the early problems were solved, and Gene has been happy with his Intrepid since. However, when Jim found that Gene had bought one, he sent a script for customers buying new or used Chryslers. If anyone benefits from this, they can mentally thank Jim...

CONGRATULATIONS, NEW CHRYSLER OWNER!

Some advice on the 4-speed automatic transmission:

This transmission, which is used in virtually ALL Chrysler Corporation [Chrysler, Plymouth, and Dodge] cars and minivans, got a bad reputation early on for poor reliability. The weaknesses in the transmission have been fixed. But there is something which is the OWNER'S responsibility to see to: the proper care and feeding of this transmission.

Observe the "Severe Service" maintenance schedule.

Use, or have your mechanic use, only a QUALITY transmission filter when the transmission is serviced. The best is a genuine Chrysler MOPAR filter. THERE IS A DIFFERENCE. Some aftermarket filters, though they fit, are actually Universal types intended to fit several different transmissions. Some have the same filter in boxes with different numbers! In the case of the MOPAR ones, every one is different!

Use, or have your mechanic use, ONLY the correct transmission fluid. Quaker State and Pennzoil make a fluid which is compatible. It is also OK. Some Chrysler owner's manuals say that you can use DEXRON if the 7176 fluid is not available. DO NOT DO IT!

If the [correct] fluid costs more (it does, about 50-60 cents a quart), PAY IT.

If you need to add a pint of fluid and [the correct fluid] is not available, drive a few miles to the next place which has it. This will be less harm than using DEXRON.

If a mechanic says he can substitute a little DEXRON and it won't do any harm, LEAVE! [and never come back]

If someone says he can use DEXRON plus an "anti-friction additive" in your Chrysler transmission, LEAVE!

If somebody puts DEXRON in, take it to a shop which uses [the right fluid], and have them drain the ENTIRE transmission, and refill with [the right fluid]. This will cost about $160.

DO NOT USE DEXRON!

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Also there is a note from one transmission builder who stated that once they adhered to the use of 7176 fluid only the return rates on A604/606 transmissions dropped to the same levels as other makes.

This is strong anecdotal evidence that once Chrysler addressed the early QC issues with these transmissions the chief problem was the use of poor quality fluid and/or the wrong fluid.

 

[FazerZ]

quote:

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Originally posted by G-Man II:

I'm not talking about flat out failures. I'm talking about issues of poor shift quality and shudder only.

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Now we are on the same page. TCC shudder is primarily caused by improper and/or old ATF use.

If we were speaking of durability, then the units have a dismal reliability record in stock factory build.

DH

 

[the_oil_dealer]

quote:

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Originally posted by FazerZ:
Even now, other manfacturers are just introducing the same/similar design ideas that chrysler had in 89

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41TE sounds a lot like the G4A-EL introduced in 87', fully electronic. That thing loved ATF+3, it appeared far more suitable than the Dexron II (III) that was recommended. I must say that Chrysler has always had some really good engineering, with the added funds, costs don't need to be cut as often. The products are reflecting this

 

[G-MAN]

quote:

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Originally posted by the_oil_dealer:
41TE sounds a lot like the G4A-EL introduced in 87', fully electronic.

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I'm pretty sure the A604/41TE was the first totally electronic automatic transmission ever produced by any car maker. "Totally electronic" means that not only the lock up converter is computer controlled, but the fluid valves are solenoid controlled, which means the shift points are completely controlled by the computer powering the solenoids.

 

[the_oil_dealer]

quote:

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Originally posted by G-Man II:

quote:

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Originally posted by the_oil_dealer:
41TE sounds a lot like the G4A-EL introduced in 87', fully electronic.

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I'm pretty sure the A604/41TE was the first totally electronic automatic transmission ever produced by any car maker. "Totally electronic" means that not only the lock up converter is computer controlled, but the fluid valves are solenoid controlled, which means the shift points are completely controlled by the computer powering the solenoids.

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Yes, I'm going by that definition as well. In the case with the G4, there was also an HL version which indeed was hydraulic but the EL was totally electronic. Of course there was no duty control, but rather line pressure was controlled by the "kickdown" cable. It had a selectable Econ/Power mode which altered up/downshift points and a HOLD 'Manual' mode for the first 3 speeds. Kinda cool for being on the market in 87

 

[G-MAN]

quote:

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Originally posted by the_oil_dealer:
Of course there was no duty control, but rather line pressure was controlled by the "kickdown" cable.

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Then it wasn't totally electronic.

 

[brianl703]

quote:

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Originally posted by the_oil_dealer:
41TE sounds a lot like the G4A-EL introduced in 87', fully electronic.

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Is the G4A-EL the same as the 4EAT that Ford used in the '91 and newer Escorts?

In the '91 Escort it had a separate transmission control module. In the '92 and later models, it was integrated into the powertrain control module.

 

[the_oil_dealer]

G-Man, I dont know of an atx that is unable to do that, be it vacuum controlled/hydraulic like the old school boxes or an electronic box like the ones we discussed. In electronic units, the TPS position and RPM/Load calculations tells the TCMs when to shift. Its specifically the duty-cycle operation (engaging and disengaging the solenoids at a frequency (40? 60hz?) to govern line pressure that makes them buzz.

 

[G-MAN]

quote:

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Originally posted by the_oil_dealer:
G-Man, I dont know of an atx that is unable to do that, be it vacuum controlled/hydraulic like the old school boxes or an electronic box like the ones we discussed.

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I've owned half a dozen cars with cruise control, both domestic and foreign and my 99 Chrysler is the only one I've ever had that will downshift on a steep hill to maintain speed. I'm talking about going DOWN hill by the way, where the cruise control is backing off the throttle to keep the car from going too fast. The only thing my 97 Olds does is back off the throttle. If the hill is steep enough, the speed increases no matter what the cruise control is set at. My Chrysler will downshift to 3rd to keep the speed from increasing past what I have it set at.

 

[FazerZ]

quote:

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Originally posted by G-Man II:
Those "buzzing noises" that a Chrysler transmission makes are the solenoids the TCM uses to downshift the transmission. The noise is there for every upshift and downshift, it's just that the overall noise level is low enough when the car is coming to a stop that you can hear it if the windows are down, or if you're standing by the car.

One cool thing about electronic solenoid control of the shifting is that the cruise control can actually downshift the transmission to maintain speed when going down a hill. [/QB]

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Actually, this is not necessarily a function of electronic shift control, but smart shift strategy that is present on some vehicles.

I am not aware of any grade control present in DCX 's vehicles. However, it could be undocumented in some later vehicles.

I think on those vehicles, its just a matter of getting the TPS or other load sensor to get to the right value to cause a downshift just as the_oil_dealer has suggested. Much like a old cable or vacuum controlled unit.

I do know Honda has a new grade control shift strategy present in their automatic transaxle controls. It actually looks for inputs that indicate the vehicle is going up or down a grade and holds the appropriate gear; decreasing excessive and annoying upshifts and downshifts.

If the control unit sees a decrease in vehicle speed and a large increase in throttle for a certain period of time, it will cause a torque-demanded downshift AND (the key) hold that gear until conditions change.

If the control unit sees a increase in vehicle speed and a closed throttle position or reduced throttle position, it will cause a downshift and if possible engage engine braking.

This is under normal driving and is directly cruise control related.

It's pretty slick and about **** time something like this is in place. I'm sure that DCX probably has silently implemented such tech. Just not widely documented.

the_oil_dealer is right on the money. The buzz of the chrysler units (i don't even have to look to tell a chrysler is a coming!!) is caused by the modulating of the solenoids to apply and release the clutch packs.

The BIG important difference here is the solenoids control the clutch directly. DCX is alone here. Most of the other manufacturers use a relay or another separate valve to control the clutch. The other advantage of this type of system is the line pressure control doesn't have to be tied to torque input. These units keep line @ three different ranges depending on which gear the unit is in.

This idea of each clutch having a separate control is where the automatics are going. Gives more precise control and helps simplify things. It simplifies the actually hydraulic control system (fewer valves), but increases the sophistication of software control necessary. Which is best? It's tough to say.

Good discussion...moving slightly off-topic.

DH

 

[the_oil_dealer]

quote:

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Originally posted by G-Man II:

quote:

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Originally posted by the_oil_dealer:
Of course there was no duty control, but rather line pressure was controlled by the "kickdown" cable.

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Then it wasn't totally electronic.

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okay.. maybe not but it didnt make unessecary buzzing noises whenever you pulled up to a light!!

 

[the_oil_dealer]

quote:

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Originally posted by brianl703:

quote:

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Originally posted by the_oil_dealer:
41TE sounds a lot like the G4A-EL introduced in 87', fully electronic.

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Is the G4A-EL the same as the 4EAT that Ford used in the '91 and newer Escorts?

In the '91 Escort it had a separate transmission control module. In the '92 and later models, it was integrated into the powertrain control module.

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Ford coded any electronic 4speed auto as 4EAT.

The transmission that the Escort has was the smaller brother to the G4A-EL calleed the F4A-EL. They used the same planetary gearset insterestingly enough. In the early 90's was a big component switchover and most of the TCMs were integrated into the ECU.