Should I try ATF+3 in my Chrysler?

[G-MAN]

I've got just over 63,000 miles on my 99 Chrysler 300M with the 42LE transmission and I'm contemplating a fluid change. Those of you who've read my past posts on the subject of ATF know I'm a stickler for using the specified fluid and ONLY the specified fluid. My 42LE came with ATF+4 in it, however I am considering using ATF+3 for the following reasons:

1999 was the model year that Chrysler switched from ATF+3 to ATF+4 and some 99 42LE transmissions were shipped with ATF+3 in them. There are no mechanical differences between the transmissions that shipped with ATF+3 and those that shipped with ATF+4.

From what I've been able to gather, the friction properties of ATF+3 and ATF+4 are the same, but the reason for introducting ATF+4 was to improve the lifespan of the friction properties, improve low temp performance, and to ensure that the factory fill could indeed function as a "lifetime" fluid. These were the only benefits of the Type 9602 spec over the Type 7176E. If that's the case, I don't see why I can't switch to ATF+3 since I'm planning to change the fluid annually from this point on.

Thoughts? Suggestions?

 

[unDummy]

I wouldn't do it. Why go backwards?

While you're at it, just use some API SA motor oil too.

Consider this:
electronic or ECU/TCU differences?
improved high temp performance and more consistent viscosity over the temp?
antifoaming properties?

The automakers are advanced enough to change the transmission programming for the better flow characteristics/consistencies of the blend compared to the mineral ATF.

Improved resistance to varnish/sludge formation when baked. Whether you change the older spec or not, the newer spec will probably leave 'less behind'.

I also don't see yearly changes as anything special. My transmissions recieve minimally 2 drain refills ever year usning synthetic ATFs.

My ol' ZF transmission(notorious lemonade maker) recieved a drain/refill every 3k miles. I think I hold the record for that transmission's longevity. It lacked an ATF cooler.

If you REALLY want to use ATF+3, invest in an ATF cooler with thermostat, an inline or additional ATF filter, and a maintenance dose of something that would help keep the internals clean(ATF protectant or known cleaner).

 

[Tom300M]

I wouldn't do it either. My first car was a 1990 Dodge Spirit with the A604. I had about 147,000 miles on it when I got it, maintenance history unknown. When I became a bit more educated about cars in general from this site and others, I decided to change the transmission fluid with some ATF+3 since it had been acting up some. I didn't really notice any difference though after the change. I later learned about ATF+4, and how I could use that in place of +3, as it is a better fluid. I did a change with +4 and noticed a difference, as the shifts seemed to be smoother, mainly the shift into 4th, which I had been getting a shutter on.
I now I have a 2000 300M which I got with 50k miles. I didn't do a fluid change right away, as the fluid looked like the dealer had changed it before it was sold, however I didn't like the way the 1-2 upshift felt at low speeds. I did a change with +4 at 60k and noticed a difference right away. The 1-2 shift felt much more "precise." In my experience with the 2 fluids, I'd stick with +4.

 

[Ray H]

Chrysler has factory filled with ATF+4 since MY 1998. The company recommends ATF+4 as backfill for ALL trannnies originally filled with ATF+3. Do as you wish, but there's probably a reason for Chrysler's advice. The good news is your transmission's no longer Chrysler's warranty problem.

 

[G-MAN]

quote:

---

Originally posted by Ray H:
Chrysler has factory filled with ATF+4 since MY 1998. The company recommends ATF+4 as backfill for ALL trannnies originally filled with ATF+3. Do as you wish, but there's probably a reason for Chrysler's advice.

---

That is simply not true. The first model year 99 LH cars to come off the Brampton assembly line were filled with ATF+3. The swtich to ATF+4 for LH cars occured during the 99 model year. The switch in the mini-vans did not take place until model year 2000.

And there are two reasons Chrysler recommends ATF+4 retroactively: (1) They no longer sell Mopar branded ATF+4 (except for NOS), and (2) the effective service life of ATF+3 is not as long as ATF+4 from the standpoint of friction mod retention.

ATF+3 should work just fine if you change it often enough. ATF+4 will (theoretically) retain its friction mod ability (under non-severe service) for the life of the transmission, but ATF+3 won't.

And my transmission is still under the extended warranty.

 

[Ken2]

An "extended warranty" is not a warranty. It is a service plan. You need to read the fine print in that contract to see exactly what it requires. If it requires the current recommended product, that that's that. Read that fine print.


Ken

 

[cousincletus]

Around here the price of ATF+4 has gone down to around $4.50 per quart at the Dodge dealer.

 

[Ray H]

My ex-wife's '99 Chrysler 300M's owner's manual clearly states ATF+4, only. The car was purchased in mid-October '98, so that spec was set in stone before the manual's copy was submitted to the publisher. However, some pre-1999 and early 1999 Chrysler products had ATF+3 underhood stickers mistakenly placed, but the actual fluid was ATF+4. Given the problems Chrysler had with its automatics during the mid-to-late 1990s, only the stubborn, truly unenlightenable would argue for the use of ATF+3 in those boxes.

 

[G-MAN]

quote:

---

Originally posted by Ray H:
My ex-wife's '99 Chrysler 300M's owner's manual clearly states ATF+4, only. The car was purchased in mid-October '98, so that spec was set in stone before the manual's copy was submitted to the publisher. However, some pre-1999 and early 1999 Chrysler products had ATF+3 underhood stickers mistakenly placed, but the actual fluid was ATF+4. Given the problems Chrysler had with its automatics during the mid-to-late 1990s, only the stubborn, truly unenlightenable would argue for the use of ATF+3 in those boxes.

---

Yeah, well...whatever. The majority of the problems with the Chrysler transmission was the fact that up until 1997 the owners manuals listed Dexron as an appropriate substitute if ATF+ (and later ATF+2 and ATF+3) was not available. What this meant was that shops didn't stock the Chrysler fluid and even some dealerships continued to just use Dexron. Chrysler knew that Dexron would not work in these transmissions all the way back to the initial testing of the Ultradrive back in the 80s. Why they continued to allow the use of Dexron is a complete mystery. They finally wised up with the introduction of ATF+4, but went overboard, IMO. To ensure that Chrysler fluid and ONLY Chrysler fluid would be used, they didn't license the formula for ATF+4 except to their OEM lubricant manufacturers. Perhaps they felt the "Dexron is interchangeable with ATF+/ATF+2/ATF+3" mentality was so ingrained that the only way out was to specify a new fluid and be the sole provider of it.

The friction modification characteristics of ATF+3 and ATF+4 are the same. ATF+4 is not a more highly friction modified fluid than ATF+4. The difference is in the base oil used, which gives a longer service life by improved retention of the friction mod and improved cold weather performance. That's it.

 

[bulwnkl]

I think one could draw an analogy this way:

"My owner's manual specifies synthetic motor oil (or perhaps synthetic blend). This model used to be factory-filled with dino and that was the specification. The synthetic is specified purely for long-drain capabilities. Should/could I use the dino they used to specify since I'm going to be changing at the old service interval anyway and it is much cheaper?"

My opinion would depend upon the conditions under which the vehicle is used. What kind of shape is the fluid in when you drain it? Do you tow or carry heavy loads? Do you do a lot of in-town or low-speed driving without turning the OverDrive off? These are the things that killed many Mopar (and Chevy, etc.) transmissions in the past. If you're using it lightly and changing often and the fluid differences you cite truly are the only differences, I think you can make the decision you're making with fair certainty, just like you could choose dino motor oil in the analogy I wrote.

I've had or used many Mopar vehicles (mostly farm pickups). I have used RedLine C+ in one of my pickup transmissions. It worked very well, but that pickup specified ATF+3 (it was a '98 with the 47RE). I have never tried a +3 or the C+ in a transmission that specified +4.

 

[G-MAN]

Well, 5 quarts of Mobil ATF+3 went in this morning. So far I don't see any difference is shift quality.

Given that the 42LE holds 9.9 quarts, I've essentially got a 50/50 mix of the old ATF+4 and the ATF+3.

I'll keep you posted.

NB: If odor is any indication, the additive chemistry used in this ATF+3 is NOTHING like the Mercon V I put in my van last week. While the Merc V has a somewhat synthetic smell, it still has the "tradtional" odor of ATF. The ATF+3 smells nothing like ATF. It has a distinct "plastic" odor, sorta like some synthetic motor oils I've smelled.

 

[99]

LOL about the Dexron issue. My 97 Jeep Wrangler has the 32RH trans and in the owner's manual and on the dipstick it says you can use Dexron II. No way in ****! I seriously hope none of the previous owner(s) did. Well I guess the trans would've been toast by now if they had. Anyways, I put ATF+3 in it and change it every year. I have seen the TSB that DC released about using ATF+4 in lieu of ATF+3. There's nothing wrong with continuing to use ATF+3 if that's what someone wants to do. With the prices of ATF+4 hovering above the $5 a quart price point, I'll continue to use ATF+3. Someone told me the ATF+4 is a full synthetic. Any truth to that? Lastly, the TSB says ATF+4 is backwards compatible with older Chrysler ATF requirements (7176, ATF+ family) but ATF+3 cannot be used in applications originally requiring ATF+4.