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Transmission FLush?

jeramie1jeramie1 Member Posts: 6
How often do you recommend this if all? Is changing your transmission filter/fluid enough or is this worth the extra money? And how much can one expect to pay for the flush?


  • q45manq45man Member Posts: 416
    For those with modern 4/5 speed AT transmissions the partially rebuilt replacement cost can run between $2500 and $3500.
    Each model has different failure modes some like the LS400 can last 200,000 miles or more since they use a premium [$5/qt] ATF and get a 2.5 qt [25%] pan drain every 30,000 miles.
    Some US transmission barely last through the warranty most have problems [not to spec by 100k].
    You must research your model to determine when the problems start [on average] and determine an economic analysis and any modifications that might extend its life! [external additional cooler], pan removal cleaning fliter change, flushes, etc.
    Transmission life is a function of average vs peak torque transmission [assuming it is kept spotless inside] and average vs peak ATF temperature.
    How much is doubling the life of the unit worth? The amount of the replacement cost. If it is $3000 you could spend slightly less than this amount on maintenance and still be ahead.
    On my Q45 the average failure occurs at 80-100-120,000 miles with minimal factory recommended maintenance. Presently I have 168k and am hoping for 200k.
    I have an external ATF cooler to lower the peak temp by 25F vs factory design [$150].
    I use Mobile 1 Syn ATF [$5x14=$75-14=]$60 more than standard], I flush every 25k....6 flushes x $160 = $960 worth of EXTRA maintenance plus two pan drops cleaning and 2 new filters say $300 I've spent $1260 and will spend another $200 before or at 200k say $1500 total or half the cost of a replacement [which are only warranted to last 12,000 miles or 1 year] they [partial rebuilds] typically last 36k or 2.5 years before you get to spend again.
    There has been no definative study on extending transmission life other than the effects of fluid temperature.
    A typical ATF flush runs $129 [BG machine] and uses 14 quarts plus a special cleaner additive and trans conditioner additive.
    Transmission repair shops/dealers stay in business because owners don't perform extra maintenance to extend the life of units, if every tranny lasted twice as long a usual half would have to go out of business ...RIGHT!
    Watch out many people when they have problems get them flushed for the first time and sell the could be buying a car with very limited tranny life...why we always recommend that anyone purchasing a used car with 70-80k always have $3,000 in reserve.
  • armtdmarmtdm Member Posts: 2,057
    If you do drain and fill at the scheduled maintenance for severe service you will never need to do a flush. New cars have a severe service life of 50,000 for tranny fluid, older may be 15 0r 30,000. If you drain and fill and if you use synthetics a flush is never necessary. I think many people have come to learn that the flushing machines were sold to dealers/garages as huge moneymakers as opposed to a needed service.

    My opinion, under normal circumstances with regular drains and fills never needed. You are flusing your money away.
  • q45manq45man Member Posts: 416
    If you remove 25% [2.5 qts from 10 quarts] you are leaving 7.5 quarts of degraded [by temperature and dirt [wear from friction disks]and suspended non magnetic metal particles] plus all the metal trapped by the filter metal screen still inside the transmission. You can never get 100% of it all out with a 100 drain and fills! A single flush gets 80-90% out and an additional pan drop and filter change gets it to 95% maybe!
    You do get some fresh additives with the drain and fill which is why the proceedure does extend life some.
    But if trany do all last 100,000 miles why are they not warrantied [36k worst 70k best], why do many sellers of aftermarket warranties require special maintenance proceedures, why are transmission shops still in business?
    You are fooling yourself if you think manufacturers care how long a tranny last beyond the warranty....just good enough so that 97.7% last till the warranty is up is the most economical point. Lux models do provide better units since a bit more is expected of them [marketing JD Powers, etc].
    Personally I could care less as either way I make revenue, actually since we installed and recommended flushing vigorously, our transmission replacement work has declined dramtically, but the associated revenue from flushing has almost made up for the lost profits plus we have more time to do more profitable jobs.
    It really depends on whether you like to spend a small amount annually or all at one time.

    How do you make much money on a $7000 machine [which requires $700 in annual maintenance]operated in our case by a $60k/yr tech taking an hour to do the job correctly using $33 worth of fluids and selling the service for $ is no more profitable than an average hour say $11 big deal. Now Joe Smoe paying a kid $10/hr can make money since it won't usually be done correctly or they will skimp on chemicals and time.
  • q45manq45man Member Posts: 416
    flush their personal cars every 15,000 miles since they get to use the machine FREE, only playing $20 for ATF and $17 for chemicals after hours. They spend the time to get the car on the rack and an hour to do it properly.
    Techs hate to work on their own cars but in this case it must be worth it and they buy parts at our cost. So plus their labor a tranny job would still cost them $2000 vs your $3,000.

    Keep up the good work discouraging people from flushing....there is a whole factory [260 employees] in Tenn. devoted to rebuilding Nissan trannys for replacement .... they need the work.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    The auto trans on my Benz has been serviced every 30K, according to the service book that came with it. Car now has 221K on it, no records of any trans. replacement. I just did an oil and filter change and I must say the trans. oil pan was absolutely spotless. I think it pays, along with periodic coolant and brake fluid and differential flushes.

    But of course, check your own car's service schedule and at least match that.
  • blkmgkblkmgk Member Posts: 54
    If automobile owners were to do a tranny flush as reccommended, there would definitely be less breakdowns and that would certainly prolong the life of your tranny.
    I have a 96 ls400 with 92k. I would like to get a tranny flush done,(among other things) where would q45 recommend and what to spend?!!
    thank you .all suggestions welcomed for maintenance at this mileage.
  • armtdmarmtdm Member Posts: 2,057
    If you have the tranny flushed make sure they then drop the pan and replace the creen/filter as the crud (trapped in filter or screen) may not be totally flushed out. Most shops DO NOT drop the pan after flushing. Thus, teh crud could be trapped in the screen or filter to cause damage. Plus, some pans have magnetic plugs, shops don't even bother to clean those (would have to drain fluid) when they flush the tranny!

    And the reason that tranny shops do so well (unfortunately, some chain shops have the same reputation as used car salesmen) is that most people never have them serviced period. A simple drain and fill (especially with a drain plug) will let the tranny go indefinitely and so easy you can do it every 15,000 miles if you wish and save money with 4 drains and fills over one flush. I have done this over the past 10 years with at least 5 cars using synthetic ATF (if the guys doing the flushes really cared about your tranny they would also push synthetic) Profits come first as always! Actually, do (drain and fill) mine every 30,000 with synthetic
    never a tranny failure and well over 100,000 miles.

    One must take everything on these boards with a grain of salt and then use ones own level of comfort in any maintenance procedure!
  • armtdmarmtdm Member Posts: 2,057
    A typical drain and fill get 50% of the fluid, not 25 %. Let's not mislead people. If only 25% I would even consider a flush but most of the time I get (especially if I let it drain overnight) 50% of the fluid.

    The most common overfill errors occur with tranny fluid because no one takes the time to heat the tranny up by driving it at least 10 miles and then checking. Dealers, tranny shops, none of them will take the time to fill it properly only the owner will do that, a voice to make sure you check that fluid when hot and go back to assure it was not overfilled or underfilled!!!!!!!

    I started doing it myself because no shop was willing to take the tech time to check it properly
  • andre1969andre1969 Member Posts: 24,491
    I'm a little confused on the terminology here. What would it be called where they take the pan off, let the fluid dump out, and then replace the filter and the gasket? Is that just a drain-and-fill?

    That's what my mechanic did to my '00 Intrepid at 30,000 miles, and it's running, so far so good, at 52K miles.
  • jinsongliujinsongliu Member Posts: 18
    I drain and fill my tranny two weeks ago. I know I overfill, does it going to damage my car?
  • gslevegsleve Member Posts: 183
    yes it is additionally if the mechanic disconnected the feed line from the radiator to the tranny and attached a clear hose into a gallon bucket and ran the car until the fluid in the gallon jug reached half way poured in 2 quarts ran again until the jug was full added 2 additonal quarts then ran again this time with another gallon jug for 2 quarts the color of the fluid would be bright red and entire tranny including the torque converter would be completely evacuated.

    This procedure is a little more time not by much given one is already lifted the car and performed a drain and fill on the transmission pan, however if this procedure is done and one used a really good synthetic procedure would not have to be repeated as often.
  • q45manq45man Member Posts: 416
    Measure the amount drained from the tranny in a gallon milk jug [with a funnel....assuming a pan drain plug] we do to get exact amount to refill!
    You will be shocked on an LS400 [2.3 quarts out of 10] on J30/Q45 [2.6 quarts out of 10.3].
    On most cars 66-80% is inside the torque convertor and won't drain.
    The flush machines recommend a solvent be added to the old ATF then the car run in ALL gears sequentially at 2000 rpm [on a lift wheels turning]for 3-5 minutes each [this takes 15-20 minutes [heats the ATF up so solvent cleans all the varnish/loose stuff from valve body passages.
    This is where some people skimp and there is a definite difference between a simple total fluid exchange and a rigorous cleaning then a fluid exchange.
    Sometimes [50/50] the first time flush aggressive cleaning doesn't result in PERFECT clean ATF and you end up just doing it twice.....failure to do enough is why some people have failures after a flush because there was just too much crap inside and the technican doesn't care enough to discuss this possibility or warn the first time user that two times [double price] may be required.
    Same with an oil change [following agressive chemical cleaning desludging] you may need an oil change every day for a week to get all the loose crud out.
  • armtdmarmtdm Member Posts: 2,057
    this is the term whether you drop the pan and fill or pull a drain plug and fill

    For reasons above I prefer not to flush. And, as noted, if solvents used can be dangerous,
  • joe3891joe3891 Member Posts: 759
    Allison recommends fluid & filter changes,and were talking about $15,000 to $20,000 units.
    The transmission problems people are having are mostly poor design.The TH350 never gave any trouble and most people did nothing to them.Then came the overdrive units,trouble from then on and all design problems.
    A flush will not fix a design problem.
  • sinjin_dogsinjin_dog Member Posts: 84
    About a month ago, I simply drained and refilled with Mobile 1 ATF (thanks armtdm). Then drove
    60 miles and performed one more drained and refilling. My 2000 Camry is even running smoother with 12500 miles on it. The Toytota dealer wanted $80 just flush them (I bring my own ATF). May be I will do one flush job sometime before 100K miles mark.
  • armtdmarmtdm Member Posts: 2,057
  • blkmgkblkmgk Member Posts: 54
    Is that no mechanic is going to treat your car the way you (owner) would. That is why I prefer to do the job myself. That is why these boards are so helpful, they give guys like me an insight into a task that sounds difficult to do but is really simple when proper instructions are followed.
  • q45manq45man Member Posts: 416
    If you call him that I'm sure he won't! They [asumming properly trained] are TECHNICANS.
    Ours are salaried [$52-65k/yr] plus 100% medical and dental. They are all certified and each has over $20,000 in personal tools, some $50,000.
    You won't find this at dealers where employees are paid by book/hr for each job they do thus short cuts are the rule in order to make a decent living with warranty work [bogging them down].
    A simple discussion [not with the service writer] as to what care you expect, the level of service you demand, and a $20 [per actual hour worked up to 2-3] tip [some in advance] to the person doing the work will get you better work than do it yourself.
  • adc100adc100 Member Posts: 1,521
    20$/hour tip?????? Are you crazy???
  • blkmgkblkmgk Member Posts: 54
    I do think that a tip might get you the attention you want , but is it necessary to tip by the hour?
    Anyways, where is your shop located, I live in atlanta and would like to have my car service by your shop.
  • armtdmarmtdm Member Posts: 2,057
    have never been considered a personal service field, like a waiter, or barber etc,.. Tipping a mechanic to work on equipment?? Guess we should tip the physician who did my colonoscopy to assure he did not screw up and pierce the intestine.

    Give me a break!!!!!!
  • bluedevilsbluedevils Member Posts: 2,554
    It should not be necessary to tip in order to get good work done on a vehicle. I was pretty offended by the mere suggestion of this.
  • bluedevilsbluedevils Member Posts: 2,554
    q45's point that a simple discussion about how the work will be done should be conducted with the technician and not the service writer, points out the absurdity of how most shops operate. The service writer/advisor is the person with whom customers interact. This is a big part of their job. It's not as easy to get the technician to take time and explain how a repair will be done. My experience is that most shops want the techs working on cars, not talking with customers.

    If the customer needs to talk with the tech instead of the service advisor to get the desired information, then maybe the service advisor is not necessary. I have felt for years that, in most shops/service departments, the service advisor is an unnecessary and unknowledgeable middle man. I've seen knowledgeable service advisors/shop managers at only one shop in my experience. Everywhere else, they didn't know a lick about what was going on.
  • joe3891joe3891 Member Posts: 759
    What made a mechanic into a technican,why the computer of course.The average 12 yr old is a great wizz at computers so whats the big deal.
  • blkmgkblkmgk Member Posts: 54
    that is the question, but it does seem like nowadays these so called "technicians" will go the extra mile if you do tip 'em. if you do not, then they will just get your car out the same way it came in. I do agree that it is absurd though to tip a mechanic, i mean a tec.
  • armtdmarmtdm Member Posts: 2,057
    I concur. I have yet to meet one that was anything more then an order writer/taker, write down the complaint and "Next" And now with coive mail, you neer even can get one to sepak with or call you back!

    Get some high school kids with a personality and they can do a better job!
  • q45manq45man Member Posts: 416
    The founders were all Infiniti certified [they were all 3 at the 1989 2 weeks launch training]; they were all the key men [training wise] at diffenent dealers in different states. Two moved to Atlanta and set up the shop in 1995.
    The key was that all techs would be salaried to remove some of the pressure to take short cuts to maximize income. Build reputation for Quality at a fair price but keep overhead low [without fancy surroundings or loaner cars].
    The service writer/store manager are ex technicans who could function with the more difficult task of dealing with customers [much more difficult than a car].
    All technicans and the store manager are paid in the same range [$52k-$65/yr] primarily based on longevity.
    The only bonus structure is if all 4 techs bill more than 200 hrs combined each week everyone gets an extra $100.
    They may work paid overtime before 8AM or after 6PM as the work load dictates....the shop is closed Sat-Sunday to give everyone time to recover.
    The average repair ticket is $334 and the labor rate is $68 per hour [Inf & Lexus parts are expensive].
  • q45manq45man Member Posts: 416
    We average just over $153 [labor and parts] per hour gross revenue based on 2700 customers whose vehicles run the gamout of Infiniti and Lexus models from 1990-2002.
    If a waiter served you food and provided extraordinary service and quality what would you tip him for this effort 15-20%?

    To a technican who may work on 20 [30] or more cars per week, one is the same as another [unless it belongs to your mother or A Friend who respects you]. Of course a certain minimum level of performance is expected depending on the wishes of management.
    Obviously many of you are so use to Quicky Lube guys and Joe the High School drop out, a real technican who spent 2-4 years attending Vocational College earning a 2 year degree minimum, going into debt spending $30,000 on tools or has a BSEE, MSIE, MBA [myself] in the repair business is rare.
  • bluedevilsbluedevils Member Posts: 2,554
    but hard to find. It's true that knowledgeable, professional shops exist. But I have absolutely no idea how to find one. That, coupled with the fact that they are few in number, makes it very tough for a customer who cares about having good work done on his/her vehicles to actually get that good work.
  • alcanalcan Member Posts: 2,550
    Canadian technician requirements: Grade 12 minimum, 9,000 hour (about 4 1/2 years) apprenticeship, 3 eight week college sessions, minimum 70% to pass the Provincial certificate of qualification exam for Auto Service Technician after all above prerequisites have been met. And still get referred to as "grease monkeys".
  • joe3891joe3891 Member Posts: 759
    Have you ever done a inframe overhaul on a DT466,it makes you feel like a grease monkey.All jobs aren't computers & sensors.
  • alcanalcan Member Posts: 2,550
    No argument about that. Did my share of clutches and rear ends in 6000 series dump trucks in my time. I think the problem stems in part from the fact that the very first mechanics were blacksmiths, and that's the perception some of the motoring public still has.
  • pronigierpronigier Member Posts: 19
    Is this any different from a flush. I was convonced I should get a flush/exchange, whatever.The chain put dextron 2 in my 97 camry. I checked the manual and it does say dextron 2 or 3. I don't think I will get it done again because the car smokes on startup now. This same shop left various hoses to the air cleaner disconnected and installed the wrong spark plugs. I don't think idleing a car for an hour to do a trans flush is good for the engine. I have been told that the smoking is probably valve seals but I can't help but think that the idleing and air cleaner hoses and wrong spark plugs didn't help any. The correct spark plugs are in now and the hoses are connected. Can I mix dextron 3 with dextron 2 when I have a good technician drop the pan and change the filter, at next service ?
  • alcanalcan Member Posts: 2,550
    Are you sure the last fill was Dexron II? That fluid has been obsolete for years, superseded by Dexron III (initally designated Dexron II-E for factory fill) which has improved additive packages to provide a better low temperature flow rate for smoother cold shifts and better thermal stability to resist high temperature oxidation and varnish formation. They are fully compatible.
  • bburton1bburton1 Member Posts: 395
    Would suggest when changing fluid you use the exact fluid recommended by the manufacturer. No car manufacturer's do not formulate ATF but they do have specific tranny designs which require specific atf performance.

    Switching to synthetic might be the ticket for a new tranny or it might provide years of trouble free service.

    Just changed the atf on my 97 accord after 30k since last change-fluid was discolored-no burnt smell and I drive almost exclusively at highway speeds. Change that ATF-the tranny you destroy could be your own.
  • armtdmarmtdm Member Posts: 2,057
    My 92 Camry calls for Dexron II but been using the Amsoil Universal synthetic ATF since 25,000 miles, change every 30,000, currently 138,000 total.

    Like oil the higher numbers can usually be used in engines etc. calling for the lower ones. IE: use a SJ oil for engine calling for SE, using Dexron III when calling for a II.

    Not true for gear oils though. Should not use a GL-5 when a GL-4 is called for.
  • wtdwtd Member Posts: 96
    My 98 chevy truck has a drain plug in the tranny. I first changed my fluid and filter at about 20,000 and than have just drained and refilled about every other oil change. fluid stays clean this way and no need for flushing.
  • dlaughlindlaughlin Member Posts: 17
    Anyone know how much fluid is needed to flush a Infiniti I30, 1997?
  • bidandsellbidandsell Member Posts: 43
    Try changing the output lip seals on a CAT 938F transmission inframe. Of course you can't steam clean it first.
  • blkmgkblkmgk Member Posts: 54
    on the bottom of the pan?
This discussion has been closed.