how much transimission fluid?

Discussion in 'GM Diesel & DuraMax' started by chasin7, Aug 12, 2008.

  1. chasin7

    chasin7 New Member

    I have a 2004 2500HD Chevy. I'm changing the tranny fluid soon. How much fluid does it hold. Not just in the pan, but the whole system? I plan on just changing it with Dexron III. That's what's recommended. Any reason to switch to synthetic? Any tips or advice as I never have done this before? I plan on dropping the pan to drain, then disconnecting the transmission cooler line at the radiator and then starting the vehicle to get the rest of the fluid pumped out. That's How I read it should be done? Do I risk doing any harm to my transmission this way? How long should it take about for the rest of the fluid to pump out once I start the truck? Thanks for any help.
  2. Crawdaddy

    Crawdaddy All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    I don't know if I'd want to start my truck up with no fluid in or available to the transmission pump. Something tells me that you'd at least start causing accelerated wear to the pump. Not to mention that disconnecting and reconnecting the transmission cooler lines are a royal b*tch because they are solid lines. I think I'd just drop the pan and filter, and leave a pan under the truck for a while. If you really want to clean/drain the transmission, I'd then refill the pan and run clean fluid and a cleaner through for a little while, then drop it a second time and put your final fluid in... I'd wait for verification from other members such as tbplus10 and collinsperformance first though before you go following my advice. :neutral:
  3. chasin7

    chasin7 New Member


    tried tackling this project tonight. The drain plug wouldn't budge and I ended up rounding it off. I didn't have the right wrench to get at two of the bolts on the pan. Could reach the rest with the socket. So I scrapped the idea until I get back from my vacation. I'm considering getting the thing flushed at a shop and just returning my supplies. Frustrating.
  4. PontiAddict

    PontiAddict Rockstar

    It all depends. What engine do you have? Gas or Diesel? Allison transmission or GM HydraMatic? I'm guessing the 4L80E is what you have...

    Just drop the pan, replace the filter, and refill. But I prefer flushing much more. But the filter needs to be replaced anyways, and doing it yourself is much cheaper than having the flush shop do it.

    As far as the amount goes, check at AMSOIL's website, I believe they tell you capacities. Otherwise, have you checked your owners manual?
  5. vegaschevy

    vegaschevy New Member

    Since you mentioned dexron 3, I will assume it is a L480E trans. My factory service manuals tell me on mine that it is 13.37 quarts aprox 3.5 gallons dry ( as in new un filled). If you just do the filter and fluid in the pan you wll need between 6 to 7 quarts. I like to pull the line off at the secondary cooler and put in a bucket ( extend with tubing). Have some one start and sit at the ready to shut off while I pour new fluid into the trans at same rate it is pumping out. When you see it coming out clean ( red) shut off reconect the line and check fluid level...add if needed and restart and let run awhile, then check again and adjust as needed.
    Pulling the line...slip the plastic cover back, use a prick or small flat head screwdriver to slip the lock clip off the line ( do not lose it). When reinstalling the clip do not force it straight on, it turns or rolls on prior to putting the line back..when the clip is on push the line back in, you will here it click. Check to see there is not a yellow ring showing ( if so try again you did something wrong).
    You may have to support the tranny and remove the cross brace and tranny mount to gat access to the back two to four bolts on the pan.
    tools 15mm socket,18mmsocket and wrench, 10 mm socket for the pan. This is based on 2002 1500HD 4x4 with L480E. 17 bolt deep pan.
  6. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    I agree, good reply. The only thing I would add is to use a synthetic oil like Amsoil, Redline, or Royal Purple. The synthetic oils last longer and can run at higher temperatures.
  7. blue99tahoe

    blue99tahoe New Member

    All right I'm getting to make a trip from MI to NE and have 116K on the clock... I plan on doing the trans, diffs, and transfer case.

    My question is when doing the DIY flush if switching to synthetic, do you drain the pan first and put a new filter on before flushing or just leave the old filter on. Then replace the filter again after the flushing. I know it is a dumb question, just not sure about the method. Because on one side you're replacing the filter twice(or not), but on the other side you're flushing new syn into the system just to drop the pan again anyways to put the new filter in.

    Any light into this would be great.
  8. vegaschevy

    vegaschevy New Member

    Here is what I did...since i would like to have used redline or ams oil, but it was not a new trans and converter and those were about $10.00 per quart..( kinda expensive to do a flush with)..I settled for valvoline $ 5.00 per quart, I think it was synthetic and is what replaces dexron 3 that I can not find anymore. picked it up at autozone ( read the back of the bottle ). I am assuming you have L480E trans( if it is an allison different fluid required). The system holds 3.5 gallons aproximately( once again different on allison). I drained the pan, then removed the pan ( took crossmember off to get to back 4 10mm bolts) replaced the filter and pan ( the factory gasket is great) and topped off with the 5-6quarts.Then ran for awhile cycling through the gears and letting her heat up to operating temperature. Then removed the grill and disconnected the line at the auxillary cooler, extended the line with a piece of hose into a 5 gallon bucket. Then while a friend started, and ran the truck I added fluid at aproximately same rate as it ran into the bucket, keeping an eye on the exiting fluid as he moved through the gears ( foot on break)...when it started running out nice and red, I had him shut it off. Then closed up the line and ran and checked fluid level off and on, let her cool down and sit for a day then started up and ran until operating temperature achieved once again, and recheck fluid level. Pull the stick out now and she is nice and red...and the trans temperature has only gotten up to the 200 mark so far sitting a traffic jam on the freeway with it being 80degrees outside..before the flush she would have been up to the red line. And after flush with the outside air temperatur in the 65 degree range, it would only get up to 150 on the guage. Went through four gallons of fluid aproximately ..well worth it. waiting tosee how she does this summer when it hits 120 degrees here.
  9. panasonic

    panasonic New Member

  10. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

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