By on December 21, 2009

Time to get out of Dodge? (courtesy: Flickr/Chad Dunbar)

Tom in North Carolina asks:

Thanks for taking on the synthetic vs. standard oil change question on my 2005 Dodge Durango a few months ago. Now for a new challenge: the same Durango, 78,000 miles, 5.7 Hemi with 5 speed automatic (trailer tow package and transmission cooler). It’s a highway cruiser, bought it to tow a boat with trailer. Except I have a boat slip now so there’s very little towing needed.

The dilemma: the manual says nothing about changing the transmission fluid if the vehicle is not used in severe service. Since I am skeptical of lifetime fluids, I think the fluid needs to be changed but don’t have any idea when to do so (FWIW: it is still a nice shade of red on the dipstick).

My options:

1.The local Dodge dealer recommends that the transmission fluid be changed weekly (well, almost), with both internal transmission filters changed, at $250 per service. Since the transmission is a closed system, I can’t really see where contaminants could get into the system that would require that the filters be changed, but being wrong could prove to be very expensive.

2. The local Tire Kingdom will do a fluid exchange/flush for $110. I used to do this every 75,000 miles with an Isuzu trooper that had a sealed transmission and never had any problems when I sold it at almost 200,000 miles. Is flushing out all of the old fluid and replacing it adequate (as long as the correct fluid is used), and more than the service manual requires?

3. Do nothing. The whole power train is overkill/overspec’d for highway trips and will probably last forever with engine oil changes and the occasional set of 16 (!) spark plugs.

I want keep the vehicle for another few years, and maintain it appropriately. It is not a Bugatti, nor is it a clunker. I am not from the “change the oil every 3000 miles because that’s what daddy did” school, nor the run it till it breaks crew. This vehicle is a heavy duty appliance, and I want to maintain it as such.

Sajeev replies:

There is no wrong answer, especially if Chrysler (and their Lifetime Warranty) stays around as long as your interest in this vehicle remains. Then again, don’t hold your breath on that.

And transmission filter(s) have purpose, needing replacement at some regular interval. But the conventional “drop the pan” service is the only way to do it. Which, if your torque converter lacks a drain plug, cannot remove old fluid as well as the “flushing machines” at local oil change places. Confused yet?

I’ll simplify: find a place with a transmission flushing machine plus a service bay to do a filter change. Ask them for a package deal on both services, unless you do have a drain plug on your torque converter. (If so, do a conventional service and hope the mechanic drains the torque converter.) And do this in the next 20,000 miles or so. Repeat again in another 50,000-100,000 miles, depending on condition of the tranny fluid as the years go by.

There’s no rush: you’re on top of things. Your game plan for the coming years determines just how bulletproof this Durango shall be in the future. And, short of doing neutral drops at stoplights, you can’t go wrong with any transmission regiment you have in mind.

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24 Comments on “Piston Slap: Dodging Trouble Again?...”

  • avatar

    Auto tranny dipstick? Consider yourself lucky…I haven’t seen one of those since 1997 :D

    This whole “lifetime fill” thing is a pretty common term these days. I can only assume it’s borne out of a median 40-something-month replacement cycle for the average car owner, as well as the desire for service centers to stick to more foolproof and higher-margin services.

    I’d personally go for the pan drop with filter change (vs just a flush). Might be the only time you ever need to do it for the rest of the car’s life, especially if you’re not doing much towing.

    • 0 avatar
      Eric Bryant

      Actually, “lifetime fill” addresses one major cause of transmission failure – over- or under-filling by both DIYers and pros. According to the conversations I’ve had with engineers at the OEMs, most users simply could not figure out how to properly utilize the dipstick, and thus the fluid level was rarely set correctly after servicing.

      If the “lifetime fill” concept for normal use makes someone uncomfortable, then just follow the factory recommendations for severe service. For those of us who make short-ish commutes in the Midwest through all four seasons, we’re already pretty close to what most OEMs consider “severe service”. If you live down south, the typical daytime temperatures can get close (or exceed) to those established as the threshold for “severe service”. Just interpret the guidelines a bit liberally, and you can find justification for frequently performing any maintenance task you wish ;)

    • 0 avatar

      @Eric Bryant

      I’d kill for a dipstick and/or easy way to determine the fluid’s properties over time. On my wife’s car (01 Passat auto), it’s $130 DIY or $400+ professionally to change 2/3 of the fluid and the filter, which also includes lots of hoops to jump through…such as a very narrow temp range for determining proper fill, as you mentioned. One of the only ways to determine overfill is when problems occur down the road.

      I just fundamentally don’t like the idea of “lifetime fill” because it’s a farce–lube fluids always break down over time.

    • 0 avatar

      Wow, my wife’s 2005 Sonata has a dipstick, I didn’t even think to look.  Just assumed it would have one.


  • avatar

    I owned a 1997 Ford F250 (light duty version) for 10 years.  Mostly, it was NOT used
    in heavy service, but as a daily driver.  I religiously changed the tranny fluid every
    30k miles (including a new filter and drain of the torque converter), and had had
    no tranny problems when I sold the truck at 160k miles.   The truck did have an
    auxillary tranny fluid cooler.

    I now have a 2005 Accord V6.  Honda gives little guidance about servicing the
    tranny.  The car has about 70k miles on it, and I have dumped and refilled the
    tranny 3 times so far.  It is my understanding that this procedure replaces about
    one-third of the tranny fluid.  So far, no problems with the tranny, or even any
    hint thereof.  Most of my driving has been highway.

    I also recently purchased a new 2009 Xterra.  The manual is a bit vague about
    tranny fluid maintenance, other than to specify the use of a very specific fluid
    that can only be purchased from a Nissan dealer.  This truck has only 3500 miles
    on it, has been used mostly for highway driving, and so I’m not worried about a
    tranny fluid change yet.  There is no tranny fluid dipstick.

    I suppose my recommendation, based on experience, is this:  change tranny fluid
    regularly (milesage or time) even if you don’t think it’s necessary.  If you tow or
    snowplow or suchlike, change more often – including filter(s) and torque
    converter.  Yes it’s expensive, but it’s cheaper than a tranny rebuild or replace.

    • 0 avatar

      Someone on an Accord forum ran the calculations. Following the directions in the manual, where you drain the 3 quarts in the “pan” and refill, 3 times (for a total of 9 quarts), it will replace the majority of the dirty fluid in the transmission. Alternately, what one forum member did, was simply drain/fill the transmission every 2nd or 3rd oil change, keeping the fluid fresh inside. There is also an interesting writeup on how to reach the “non serviceable” filter in the V6 transmission.

  • avatar

    I have recent experience that suggests you may not want to touch it at all.  My wife’s 2004 Mercury Mountaineer has 65k on it.  We had never had the tranny fluid changed.  It had been shifting abnormally lately so I took it in for the flush and change.  Tranny immediately grenaded after that, and we just swallowed a $2000+ bill for a rebuild.

    • 0 avatar
      John Horner

      Ah, the myth that clean transmission fluid kills transmissions. Would you say the same thing if your car had a rod knock, you changed the oil, then the rod let go?
      The abnormal shifting you noticed was the first sign that something serious was going wrong. Whatever that problem was is what led to the complete failure, not the fact that you put new fluid in it.

    • 0 avatar

      It’s not a myth, here’s how that works (and why the Durango owner doesn’t need to worry about it):
      If your transmission is going, there will be a lot of metal shavings in the fluid. The shavings add friction to the gears and keep them shifting, when you change the fluid, it is much slippier and the already stripped gears will no longer grab, and your transmission slips.
      You want to change your transmission fluid before your gears are stripped, not after. After it’s too late and you should just drive on the tranny until you can afford to replace it (or you get stranded, whichever comes first).
      So with a new transmission, change the fluid on a regular basis (20000 miles seems like a good number to me, but go with what the manufacturer recommends if you don’t feel otherwise). If you have an old transmission and never changed the fluid, don’t change it now (especially if it’s acting up, it will just get worse).

    • 0 avatar

      You’re almost right, dolo…it’s not metal shavings, its ATF contaminated with the remains of your clutch packs that turns ATF into maple syrup.  Replace the syrup with slippery oil and what’s left of the clutch packs disappears in a hurry.  

  • avatar

    Do not do only a “flush and fill”.  I once spent $110 on this service only to discover that it does not include a filter change.
    It is a myth that leaving tranny fluid alone is best.  The fluid eventually breaks down chemically (even if remains red), and no longer lubricates as it should.  Gear and torque converter wear generates particulates that can eventually clog the valves and orifices inside the transmission, in spite of the pan magnet designed to catch much of them.  The dealer will be happy to replace the transmission after the warranty expires – at your expense.
    Have the pan dropped, and filter and fluid changed with only a Mopar product – nothing else.  The pennies you save on Brand X aren’t worth it.
    This is a service I perform myself every 25k miles on ATFs – particularly on my Chrysler minivans – and have encountered no problems with their transmissions.

  • avatar

    We have a 2003 Dodge Durango in our family, one of the older, smaller models, with a 4.7 litre engine and one of those goofy sort of five more like four speed transmissions.

    The owners manual said to change the fluid and filter at 100,000 miles which I did at Cottman Transmission. I had a coupon and the filter and fluid change cost about $75. The truck now has about 125,000 on everything seems to be fine (and I’ve got a teenager driving it!).

    You can try this approach as a suggestion….

  • avatar
    John Horner

    Drop the fan, change the filter, refill the tranny. Then, flush the tranny to get the majority of fluid which can’t be gotten to by a pan drop. Use ATF+4 fluid as specified for Mopars. Don’t let a shop use some “universal” fluid, or worse yet use generic Dexron plus a bottle of lubeguard.
    I do tranny services every 30k miles on our vehicles. This might be overkill, but modern automatic transmissions are very,very expensive to replace.

  • avatar

    The main job of automatic transmission fluid is to provide hydraulic pressure to change gears while dissipating heat.  It does not perform the same exact primary function as engine oil which is to lubricate.  Dirty ATF (which the questioner’s is not) with some metal shavings is not necessarily trouble for a tranny.  Changing ATF on a regular basis is no guarantee of future problems and can, in fact, be the source of trouble down the road.  Everytime you let a tech drop the pan you raise the risk that he’ll foul up.  Perhaps he’ll put the wrong fluid in (especially if he is not a Chrysler tech!), put too much/little in, or his not-yet-amortized tranny fluid flusher machine gets used improperly damaging your $3000 tranny in the process.  For the kind of duty described LEAVE IT ALONE!

    Chrysler engineers know best. Here’s an article from a couple of years ago quoting the manager of Chrysler automatic transmission engineering about the issue:

  • avatar

    I know the “flush” is supposed to get all the fluid, but doesn’t that put undo stress on the seals and parts of an older transmission?  (Or is that another myth, B&B?)  Isn’t it safer to just drain it and leave a little fluid behind when your dealing with an say a transmission with more than about 50,000 miles?

  • avatar

    What about rear diff fluid? I’ve got a Dakota and when its cold the rear end has a noticeable vibration, but things get smooth once its warmed up.

    • 0 avatar

      JMII, what does your owner’s manual say?  Chances are (unless you tow or operate your truck in some kind of severe commercial duty conditions) the manual tells you to leave the rear end oil alone.  Don’t fix what ain’t broken.

    • 0 avatar

      I’d have the differential checked and gear oil changed. My friend had his 1999 F150 differential fluid looked at around 99,000 miles and the mechanic said he was lucky he brought it in. The gear oil was very thick and somewhat low, differential probably would have worn gears in another 20,000 miles or so.  Currently has over 145,000 miles on the F150.

  • avatar

    Don’t forget that transmission has 2 filters – the “normal” one that picks up the fluid going to the front pump, and one for the converter/cooler return. Both are accessed through the pan, and the converter/cooler return one looks like a minature oil filter.

  • avatar

    I too own a 2003 Durango with the 4.7 V8. It’s been more trouble free than the wifes  Toyota RAV4. The transmission is, I believe a Mercedes sourced unit that has 4 gears upshifting and 5 downshifting. The reason for this is the customer notices the abruptness of a downshift much more than an upshift under acceleration so the extra gear on the way down “smooths” it out.

    I agree with Eric, follow the factory recommendations for severe service – if you must. My guess is you can leave it be and it will be fine. I have contemplated doing this myself but so far I’ver resisted going to the dealer to drop the pan.

    I would reccommend against getting a flush. Chrysler transmission are very picky about the fluid they use. One of the problems with the early 90’s trannys is the owners manual and the dipstick itself said to use dexron(?) fluid when it should have said ATF+3. Service techs put the wrong fluid in some causing many of the units to fail. Today Mopars use ATF+4. If you hook up your Durango to a flushing machine, how do you know that there isn’t some residual fluid no matter how small from a previous flush? I wouldn’t risk it. Drop the pan if you must, but DO NOT flush! And NEVER, EVER, NEVER let someone tell you they can put an additive in their transmission fluid and it will be “just as good as” ATF+4. Run, don’t walk, away from that person.

    There is a good Durango forum on Yahoo. Just go to Yahoo Groups and search for Durango. It’s run by a service tech who works at a dealership in Houston I think. They seem to give solid advice fwiw.

    • 0 avatar


      The transmission (known as the 545RFE) is a pure Chrysler design and was originally launched along the then also new 4.7L V-8 in the 1999 Jeep Grand Cherokee (although at that time it was call the 45RFE). You might be thinking of the Mercedes “hand-me-down” A580 that is used in the 300/Charger and Grand Cherokee SRT-8.

  • avatar
    George B

    I drain and replace the transmission fluid myself, replacing the drained fluid with whatever fluid the manufacturer used.  For my next car I plan to change fluid at 20k to 30k mile intervals.  Buy automatic transmission fluid at the dealer to avoid possible warrantee disputes with the manufacturer.  To avoid adding too much or too little transmission fluid, I carefully measure the volume I drain out and double check with the dip stick.  If the transmission has a filters that can be replaced, I pay a reputable independent shop to drop the pan and replace filters and fluid per the severe condition service interval.  Not much of a fan of transmission flushing.

  • avatar

    I agree with John Horner. 30K miles max between fluid/filter changes. Also, if you do it yourself, make sure  you do a cross hatch pattern when you replace the bolts. There are alot of them. In addition, don’t over tighten them! If you strip one, you will be in a world of hurt. Finally, clean the magnet off in the drain pan and make sure the old gasket is cleaned off the pan and trans. Or just pay some shop to do it!

  • avatar

    I almost forgot: If a shop tells you that your trans is ‘sealed’ and service is not required, go somewhere else. Transmissions are not sealed. The shop tells this to people that do not know much about cars because they (the shop) do not want to be liable if they damage your transmission. Also, if a shop has a transmission flush machine/service, they will tell you that filter change is not required/transmission is sealed ect. That is because they have to pay for their machine! I find quick lube shops are famous for this. Just something I have experienced, and something to keep in mind. Hope this helps, and good luck!

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