Forum Discussion

azdryheat's avatar
azdryheat
Explorer
May 28, 2021

Tranny fluid change

Got 70,000 miles on the current ATF oil, so today it and the spin-on filter got changed. I also dropped the pan to see if there was any sludge and it was clean. Love this Duramax/Allison combo.
  • Seon wrote:
    Cummins12V98 wrote:


    What about all the "OLD" ATF left in the converter???


    You'll never get all the oil out, even by a professional shop



    Next time someone drops their oil pan, best to install an oil pan drain plug. Much easier for the next oil change.



    allison already has a drain plug. no need to add one.
  • rhagfo's avatar
    rhagfo
    Explorer III
    Geo*Boy wrote:
    Seon wrote:
    Cummins12V98 wrote:


    What about all the "OLD" ATF left in the converter???


    You'll never get all the oil out, even by a professional shop

    Yes you can. Fill the transmission up, according to the dipstick, remove the return line from the oil cooler, install hose fitting, start truck, pump out a gallon, refill repeat until nice clean fluid appears.


    Did this on both of my old Ford C6 transmissions. What I did was start and start adding as it drained the keep up as helper went through the gears slowly.
  • The Allison does come with a drain plug. I was just curious to see what was in the pan. Oh, and Allison does not recommend a fluid flush or exchange.
  • azdryheat wrote:
    Got 70,000 miles on the current ATF oil, so today it and the spin-on filter got changed. I also dropped the pan to see if there was any sludge and it was clean. Love this Duramax/Allison combo.


    Pretty much what I found when I did my ATF along with a small amount of fine particles on the oil plan magnet.
  • Seon wrote:
    Cummins12V98 wrote:


    What about all the "OLD" ATF left in the converter???


    You'll never get all the oil out, even by a professional shop

    Yes you can. Fill the transmission up, according to the dipstick, remove the return line from the oil cooler, install hose fitting, start truck, pump out a gallon, refill repeat until nice clean fluid appears.
  • Seon wrote:
    Cummins12V98 wrote:


    What about all the "OLD" ATF left in the converter???


    You'll never get all the oil out, even by a professional shop



    Next time someone drops their oil pan, best to install an oil pan drain plug. Much easier for the next oil change.



    Too funny, the only vehicle I have not done a complete fluid exchange on is my current AISIN. It does have a factory pan drain plug as I would assume the Allison does.
  • Seon's avatar
    Seon
    Explorer II
    Cummins12V98 wrote:


    What about all the "OLD" ATF left in the converter???


    You'll never get all the oil out, even by a professional shop



    Next time someone drops their oil pan, best to install an oil pan drain plug. Much easier for the next oil change.

  • azdryheat wrote:
    Got 70,000 miles on the current ATF oil, so today it and the spin-on filter got changed. I also dropped the pan to see if there was any sludge and it was clean. Love this Duramax/Allison combo.


    What about all the "OLD" ATF left in the converter???
  • ktmrfs wrote:
    azdryheat wrote:
    Got 70,000 miles on the current ATF oil, so today it and the spin-on filter got changed. I also dropped the pan to see if there was any sludge and it was clean. Love this Duramax/Allison combo.


    no real reason to drop the pan. Only time the pan needs to be dropped is if there is some reason to do internal transmission work. That's what's nice about the spin on filter.

    I went to the deep pan on both my trucks, rather than the shallow pan the truck comes with. So the pan did come down for that. Being overly anal mostly.

    BTW, on both my duramax trucks, I did a drain and fill with allison transynd rather than the GM fluid. Lasts longer, holds up better, and NAPA sells it at reasonable prices.

    I dropped the pan to get all the oil out (about 1/2 quart was still in there) and to check for sludge (102,000 miles on the ODO).
    I checked on the 295 oil and but went with Valvoline VI since it's done a great job so far and I didn't want to drive across town to NAPA.
  • azdryheat wrote:
    Got 70,000 miles on the current ATF oil, so today it and the spin-on filter got changed. I also dropped the pan to see if there was any sludge and it was clean. Love this Duramax/Allison combo.


    no real reason to drop the pan. Only time the pan needs to be dropped is if there is some reason to do internal transmission work. That's what's nice about the spin on filter.

    I went to the deep pan on both my trucks, rather than the shallow pan the truck comes with. So the pan did come down for that. Being overly anal mostly.

    BTW, on both my duramax trucks, I did a drain and fill with allison transynd rather than the GM fluid. Lasts longer, holds up better, and NAPA sells it at reasonable prices.