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Allison transmission flush?

Discussion in 'Chevy Trucks' started by RCsLawncare, Jan 21, 2010.

  1. RCsLawncare

    RCsLawncare Senior Member
    Messages: 459

    Dealer says flush it for $250 bucks. It has 140k, got it with 110k with no maintenance history. Kinda wondering if I should leave it or have it flushed. Good? Bad? What do you all thing?
  2. sweetk30

    sweetk30 PlowSite.com Addict
    Messages: 1,588

    easy to do. i just did one.

    8 qt of good atf dextron 3 or better.

    1 spin on filter for the allision.

    around 30 min and basic tools.

    pull drain plug on pan. catch the fluid. reinstall plug.

    remove spin on filter. AND SWAP the magnet over if stuck to the filter. install the new one. http://www.napaautoparts.com/Search/Detail.aspx?A=ATP18592_0259785570&An=599001+102003+50014+2014039

    refill the tranny with around 7-8 qt of fluid till in the cross hatches on the stick.

    easy and simple. with that mileage thats all i would do.
  3. RCsLawncare

    RCsLawncare Senior Member
    Messages: 459

    So just draining the fluid would be better than actually flushing it. Thats what I wanted to do, but they had to give me the run around on why its better for them to do it.
  4. RCsLawncare

    RCsLawncare Senior Member
    Messages: 459

    Also, what's the best fluid I can get if Im just draining it. Can I mix something like royal purple into it? Any better or just stick with the basic stuff?
  5. Q101ATFD

    Q101ATFD Senior Member
    Messages: 277

    The best stuff, hands down, for an Allison transmission is Transynd, made by Allison. They claim a 100,000 mile drain interval when you have 90+% Transynd. One drain and refill will get you to 57%, and another drain and refill will put you at 83%. Of course you can use any approved Dexron-VI, however, I think that the MY 2003 Allison seals don't like synthetic fluids, with the exception of Transynd.

    EDIT: Per Allison, synthetic fluids should only be used in Allison transmissions with a serial number greater than: 6301670488 OR 6320784373. Numbers before those should only use non-synthetic Dexron-III.

    Clear as mud?
    Last edited: Jan 21, 2010
  6. RCsLawncare

    RCsLawncare Senior Member
    Messages: 459

    Good to know, I appreciate the info!!!
  7. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    Here's a good procedure to safely exchange the fluid in your transmission. I don't know what the total fluid capacity of the Allison is, it should be in your owner's manual. You'll want at least a couple extra quarts. This will give you 90% plus new fluid.

  8. stacks04

    stacks04 Senior Member
    from ct
    Messages: 119

    do the flush. the allison holds about 15-16 qts between the torque converter and the coolers. the trans also has 2 filters, the spin on and an internal filter like always. that kinda milage i would do everything. it will be much cheaper than the 2 grand to rebuild it if it takes a dump. just draining the pan only gets 50% of the fluid.
    if you go to synthetic you will need to change the fluid a few times also if you dont do the system flush. you will need atleast 2 drain and fills with the synthetic to be more than 75% synthetic fluid.
  9. brad96z28

    brad96z28 PlowSite.com Addict
    Messages: 1,526

    Draining it only does about half the fluid. Thats like pissing in the ocean. Might as well do it rite if ur gona do it at all.Im using dex 6 full syn in mine.
  10. grandview

    grandview PlowSite Fanatic
    Messages: 14,609

    I thought BB said not to flush it as recommended by GM.
  11. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    I'm sure he'll chime in soon. He "endorses" the exchange procedure I outlined in the thread I linked, at least for the 4L80e and 4L60e transmissions. I'm not sure why the Allison would be different, but he is the expert.

    Where's the "we're not worthy" smilie thingie :laughing:

    <object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/-FucbvoFFy0&hl=en_US&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/-FucbvoFFy0&hl=en_US&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>
  12. sweetk30

    sweetk30 PlowSite.com Addict
    Messages: 1,588

    make sure thay have a machine for allision trannys.

    a std flush machine cant handle the pressures of a allision tranny.

    i know of a shop that blew one up. :laughing:
  13. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    The Allisons have a higher pressure on the cooler lines?
  14. exmark1

    exmark1 PlowSite.com Addict
    Messages: 1,321

    With the higher milage I would just drop the pan and filter and fill dont power flush the system out.

    We drop the pan and filter on all of our truck 2 x per year or every 10,000 miles I have never replaced a transmission since we started doing this 5 years ago.
    We have some higher milage trucks that have been plowing for years this way with no issues!
    2003 Dodge Diesel 101,000
    2001 Dodge Diesel 148,000
    2000 Ford F-250 Diesel 125,000

    All 3 have the original tranmissions with no work done to them! The 2001 Dodge has been plowing and towing daily since it was new
  15. brad96z28

    brad96z28 PlowSite.com Addict
    Messages: 1,526

    A flush machine does not use any added pressure then what the trans makes on its own. It simply exchanges the fluid. As the old fluid is exiting the line the new fluid goes in the other side. How does that hurt anything? Why not do it please explain? I do them several times a week, and it is recomended by most auto manufacturers.
    Last edited: Jan 22, 2010
  16. brad96z28

    brad96z28 PlowSite.com Addict
    Messages: 1,526

    Yes they do, copmared to most of the trans that I have had gauges on. And they have some huge adaptors to hook up to at the cooler lines.
  17. RCsLawncare

    RCsLawncare Senior Member
    Messages: 459

    pictured a flush putting new fluid in at a high pressure forcing it through the transmission. Id rather know it out in one shot. After doing that, i will drain and change the filter every 15k. doe's that sound like a good plan? Just don't want to hurt it as it costs a lot and runs fine now!
  18. brad96z28

    brad96z28 PlowSite.com Addict
    Messages: 1,526

    Sounds like the procedure above does almost the same as my flush machine just not as neat. I would try that If I where u. And with flush machines they should call it a fluid exchange not a flush. Where someone came up with power flush thats a new one to me. Ur not gona hurt anything whatever u decide to do. But the more fluid u exchange the better. 15k is a bit early 30 k is more like it unless it starts to look dirty before then.But that will also depend on what fluid u end up using.
    Last edited: Jan 22, 2010

    NICHOLS LANDSCA PlowSite Veteran
    Messages: 4,362

    The serial # issue is dependent on which plant it was made in. I don't remember which is which.
  20. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Show me proof where "most" OEM auto manufactures endorse a trans fluid exchange procedure be done as a periodic preventative maintenance procedure.

    Dealers and shops do, and so do the manufactures that produce the exchange machines, but you won't find enough OEM auto manufactures to group into your "most" category. Because they do not recommend or endorse trans fluid exchanges as a periodic preventative maintenance item.