Valv

I intend to drain my transmission completely and replace fuild with Amsoil. Looks like ti takes 12 quarts to fill and empty transmission. I have 4 gallons.

What is the correct procedure to replace all fluid and not wasting too much oil ? After all it's $ 30/gallon

I was thinking to remove a cooler hose and run engine while I fill from the input tube, until I see fresh fluid coming out. Is it ok ?

SmokinDodge12V

A complete flush is gona take more than 12qts your best bet is to take it to a place with your fluid that has a flush machine.

mikmaze

so the flush machine is going to be able to get all the fluid out? and I too am thinking of switching soon, maybe royal purple in mine.... same time goin to a double deep mag hytech, 4 extra quarts.

Valv

I've heard of many instance where the transmission developed problems after using a flush machine, regardless of brand.
In fact many mechanics use more or less a method like I described

BroncoAZ

Tag for later. I'm going to be installing my MH DD trans pan next month, I've got 4 gallons of ATF+4 on hand.

badme

Flush machine is the only way to get all the fluid out without taking the tranny apart. It will use more than 12 qts to do it. Your way will work as long as you can pour in the fluid as fast as you are pumping it out. 12 qts out and 12 qts in will be close to a full flush. You will need to have a container to dump the old into, that is marked for 12 qts.

Ducman82

i used my friends flush machine, just taps in line with one of the trans cooler lines. i did a mag hytec as well. first i dropped the old pan, new filter, then filled, then added about 15 quarts the the flush machine till the fluid going in was clear. worked great!

Grit Dog

Should work the same as flushing my Alli trans. Most all the oil is in the pan and TC. Dump the pan and refill. Disconnect the line to the cooler. Run truck for a couple seconds, replace what you pumped out. Do it 1 or 2 more times until you've replaced at least the total trans capacity, should be able to see when it is pumping out the new juice.

SOhappy

Don't do the flush machine- too many bad experiences with that. You're initial thoughts are correct. 4 gallons is exactly what you need. Just take the return line off the tranny, attach a 3' length of garden hose with a hose clamp, and drain it into an empty milk jug 1 gallon at a time by briefly starting the engine in neutral (you'll get about three gallons, because you already drained 1 gallon out of the pan). Be sure and fill the pan first and add a gallon after each one you take out. This does a complete fluid exchange without loosening particles that could cause problems later down the road.

SmokinDodge12V

What you just described is basicly what a flush machine does only that as it takes fluid out it is returning it at the same time throught the cooler lines.

Swarthy Dago

so........ so happy, what kind of bad things have happened ? to you ?

DBLR

Here is what Amsoil show: Automatic Transmission, Total Fill 4 speed 48RE..........17.0 quarts.

My self I would first change the filter and then buy 3 gallons of cheap Walmart ATF+4 to flush out the old fluid and then pour in 17 qt's of Amsoil ATF. Yes its cost to wast 3 gallons of Walmart ATF but then you also get all of the old junky fluid out being you show in your sig that your truck has 97,000 miles on it. Also you did not say if you owned it from new and if so had it serviced at regular intervals..

JMHO

Valv

Ok, job done, everything worked great.

I drained pan and changed filter, filled again with Amsoil ATF then removed rearmost line on transmission, attached a 2 ft rubber hose and started the truck, drained all fluid while refilling with new, after 3 gallons fluid became nice bright red.

I kept adding untill almost the whole 4th gallon was gone too, then shut off and topped transmission with 3 more quarts.

I probably could have saved 1 gallon and quit after 3 but I wanted to be sure almost all old stuff was gone.

Now I have Amsoil everywhere, 15x40 in motor, 75-90 differentials, and ATF in transmission and transfer case. I bought everything at the Amsoil warehouse and saved a bundle. Cost me around $ 320 for all the lubricants.