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Mixing ATF and DEXIII

Coastie

Coastie

NAXJA Forum User
Location
Upper Peninsula, Michigan
Okay so when I swapped in my transmission I filled it with ATF because I could not find a good source of DEXIII at the time but have now found a store that sells it.

We all know that DEXIII is supposed to be better for the AW4 than ATF so I would like to do a complete fluid change. For me to do this I would need to drain and fill by transmission a few times replacing the ATF with the DEXIII, does anyone see any problems with this?
 
Coastie said:
Okay so when I swapped in my transmission I filled it with ATF because I could not find a good source of DEXIII at the time but have now found a store that sells it.

We all know that DEXIII is supposed to be better for the AW4 than ATF so I would like to do a complete fluid change. For me to do this I would need to drain and fill by transmission a few times replacing the ATF with the DEXIII, does anyone see any problems with this?
Click to expand...

by atf do you mean atf+4? if you did put atf +4 in it 4-5 drain and fills with merc dex should do it. remember to cycle through the gears and make sure it shifts into overdrive, lock out in between drain and fills. mike
 
ehall said:
if you have a tranny cooler you can disconnect the return line, and shoot the fluid into a catcher while pouring in new fluid from the top. disconnect the coil wire on the dist cap and it won't start.
Click to expand...

I thought the engine needed to be running and the tranny be able to go through gears for this to work.


x99j said:
by atf do you mean atf+4? if you did put atf +4 in it 4-5 drain and fills with merc dex should do it. remember to cycle through the gears and make sure it shifts into overdrive, lock out in between drain and fills. mike
Click to expand...

Yes I mean ATF+4 and what I am worried about is the time between fills where it would have a mixture of DEX and ATF in there. Everything I read says to at least take it around the block a few times which makes sense.
 
care to say were you found dexIII? all ive found in my area was the dex/mercon stuff now. of course the counter man said it was still dexIII just a differant name, but i havnt researched that yet.
 
Dexron II and III is no longer licensed by GM, and they only licenses Dexron VI ("6") for production now. Dexron VI is backwards compatible with II and III. I run it in my tranny and tcase and it works great.

Stuff that is labeled II or III is only going to be "compatible" at the price they could make it. I wont run that crap.
 
great thanks. ill ask my local napa about it. we too have a small napa store. small farm town so they carry alot of stuff normal napas dont.
 
I've had 6 quarts of this: DEX/MERC for high mileage vehicles sitting around with the tranny filter/gasket kit waiting for me to flush it. The salesman told me it was the same as whatever is listed in the Haynes manual. Is this the proper stuff? Do I need to look for different fluid? Any other trans fluid change tips?

Thanks
 
HenryKrinkle said:
I've had 6 quarts of this: DEX/MERC for high mileage vehicles sitting around with the tranny filter/gasket kit waiting for me to flush it. The salesman told me it was the same as whatever is listed in the Haynes manual. Is this the proper stuff? Do I need to look for different fluid? Any other trans fluid change tips?
Click to expand...

Dex/Merc III on the label will work in your AW4. You'll have a little left over (2 quarts or so) if you just drop the pan, replace the filter and refill. You can do a "poor mans flush" if you want (search), but you'll need more fluid with that technique.
 
ehall said:
The starter spins the flywheel, which spins the crankshaft, which spins the transmission input shaft. The pump should work from that, although I'm not 100% on it
Click to expand...

I could see that burning up a starter and/or killing a battery in a hurry....

Personally I would either do a series of drain and refills (changing the filter on the last one), or pop the tranny cooler line off, leave the engine running and trans in park and let it shoot some out into a container. It'd be helpful to have someone else there to add in new fluid as the old stuff comes out. Then I would drop the pan once I feel like I have pretty much all DEX in it and do a normal fluid and filter change.
 
If you just remove the sump plug without removing the filter, you'll only let out about 2 litres. So don't go pouring in any more than that otherwise you'll overfill. Ask me how I know! I flushed my system through by giving it about 6 or 7 changes thus way. Driving about 15 miles between each change. I didn't want flush the proper way as I heard some horror stories and this way worked fine for me.
 
the aw4 has a screen, not a media filter so i would leave it be and just exchange the fluid. mike
 
what are some of the symptoms of useing the wrong fluid? my aw4 has a bad whine when put in gear even at a stand still. seems like whenever there is any load at all it will whine. when i am at a coast downhill and there is very little load/line preasure, the whine dissapears for a moment untill i put a little load back on. other than the whine, the trans seems to be working great. shifts strong and all gears are fine. could this possibly be just the wrong fluid or clogged screen?
 
x99j said:
the aw4 has a screen, not a media filter so i would leave it be and just exchange the fluid. mike
Click to expand...

The one I got (told is for AW4) is a metal cartridge about 9"x5"x1/2". It is sealed around the perimeter with a hole on the top and a smaller hole on the bottom. Is this what you're talking about? It'd be much easier on me to just change the fluid, but if the trans would be better off if I cracked it open and changed this cartridge, I guess I'll do it...
 
HenryKrinkle said:
The one I got (told is for AW4) is a metal cartridge about 9"x5"x1/2". It is sealed around the perimeter with a hole on the top and a smaller hole on the bottom. Is this what you're talking about? It'd be much easier on me to just change the fluid, but if the trans would be better off if I cracked it open and changed this cartridge, I guess I'll do it...
Click to expand...
that is what i am talking about. if you look inside tha cartridge it is a screen:lecture:
 
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