: Flushing 4T80E....how many quarts of fluid?

08-26-05, 11:49 AM
Do I need...? It says-

-Bottom Pan Removal (requires drain plug removal) 11.0 quarts

-Complete Overhaul (with existing converter) 12.6 quarts

-Dry 15.0 quarts

The reason I ask, it that I'll be using a flushing machine which will pull more fluid that just puuling the bottom drain plug, but it will flush it completely dry. What I'm wondering is, how much could I safely put in, using a flushing machine, so that I know it's no over/underfilled?

08-26-05, 12:30 PM
Well, I just read the piece abotu not flushing the trnasmission due to debris being circulated, so now I just gonna drain it, and replace the filter I guess. My original question as to how many quarts I shoudl use still stand though. Thanks in advance.

08-26-05, 01:51 PM
Good idea on avoiding the flush.

When I changed mine, it took 12 or 12.5 quarts. When you take the pan off, it's going to make a big mess unless you have a large enough container to capture what comes out around the edges of the pan or you control the removal so you will know where the fluid is going to come out. Just be careful with the pan and don't allow it to bend or flex too much.

Once you have it off there, clean it out well and remove the magnet and clean it as well. Make sure you put it back where it was. The screens can just be removed, backflushed a bit, and reinstalled. They don't need to be replaced. There is a "hidden plug" that will drain the fluid from behind the side cover. I can't tell you offhand which one it is, but if you have a manual or diagram of it, you should be able to figure out which one it is. Once you've got it drained, screens reinstalled, pan and magnet cleaned, reinstall the pan using the torque and bolt sequence recommended in the manual to make sure you're not bunching up the gasket in one place. The OEM rubber gasket is reusable, so you don't need to rip it off there and use a crappy cork one. Just wipe it off well and make sure the sealing surface is also clean. Once it's all put back together and torqued properly, fill 'er up with fresh Dexron-III fluid. I think I remember our old friend saying that they come filled with Texaco brand fluid from the factory. I would check it at 11 quarts first just to be safe, then top it off as necessary. Don't want to have to loosen up the pan again just to drain out 1/2 qt. of fluid.

Let us know how you do it and how much fluid you use. I'm guessing it will be 12.5 quarts like mine was.

08-26-05, 05:37 PM
I just did mine in spring and I replaced about 12 qts, maybe a bit more.

08-26-05, 08:02 PM
Cool thanks for the replies. I guess I'm off to Pepboys to pick up a case of tranny fluid then. I'll let you know how it goes after I get it done tomorrow.

08-26-05, 09:24 PM
You can avoid some, or all, of the mess by pumping the system dry before you remove the bottom pan. Simply open the return line from the radiator-transmission plumbing and insert a fitting and hose to direct the fluid into a bucket. Much less clean-up; in fact, no clean-up.

But then, I do not remove the pan at all. Fresh fluid is all that I want. No gasket problems, no tranny fluid running in my armpits and eyes.

Thirty minutes labor, tops. Do it every (fill-in-the-blank) miles.

08-27-05, 12:31 AM
Well, it turn out that I got kind of side tracked watching that movie Collateral or whatever (pretty damn good) and never made it to pepboys. I think I'm gonna hold off on the tranny fluid change until my next open shop in 3 more weeks, and just concentrate on the Engine mount work, as well as the tire balance and alignment I had planned. The tranny is in tip top shape anyway, so it's not like I need to get it done right away.