AW4 transmission flush

Did a flush and filter replacement on the transmission today. 1997, NP242, AW4 trans, 4.0L six.

A couple of hints.

1. Undo the connection of the line to the back of the transmission to do the flush. You'll need a short piece of hose to slip over the line to get the fluid in the bucket, but it's worth not messing with the connections at the front.

2. If the fill/dipstick tube doesn't come apart like it should, cut to the chase and support the transfer case on a jack, drop the crossmember and pull the whole thing out the bottom. I fought it for an hour before realizing this.

3. There is a post on the poor man's flush, it works well. Four quarts out, four new quarts in, four more quarts out, drop pan, replace screen, reinstall pan, four quarts in, check fluid. I needed one final quart to top off.

4. Use the right fluid. I had my fluid changed (sucked out thru the dipstick hole and refilled) at a quick-change place, they used something that started to slip and never dropped the pan to do the filter. Now it's clean inside, has a new screen/filter, and the correct fluid (DextronIII).

Mark

Excellent post Mark.

My hints.

Agree! Use ONLY Dexronlll. Period.

-Use a 5 gallon Bucket for flush. Using water, mark the level each 2qts . This makes it easy to keep the qts Out and qt's IN about equal while flushing.

-use clear plastic tubing long enough to have bucket out where it can be watched while running.

-Flushing-run 2 qts Out-Stop-Add 2qts, Repeat 5 times. (12 Qts total)

-dipstick tube - Gently swing the back of the pan side to side while gently pulling down MAY help! Be sure to silicon spray that o-ring going back in.

-leave atf fluid a 1/2 to 1 qt. low and wait until AW-4 is Fully Hot (20 to 30 minute drive) to adjust to final level.

-Note: the dipstick is in the corner of the pan so pan must be real level to get a true reading. Also atf hot.

-It is Easy next time with a good set up.

-Add a cooler and temp guage and enjoy the Great AW-4.

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