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Flushing the Transmission Fluid (myth or fact)

The garage I used to work at used a machine that connected into one of the tranny cooler lines, measured the quantity of fluid coming out, and pumped in the same amount going back in (you didn't even have to connect the lines carefully, it figured out which one was pumping and auto-switched the lines internally if you had them swapped) - as I don't have 7 thousand dollars on hand to buy such a machine, I've been considering using a pair of 5 gallon pails to do the same job in a more ghetto fashion - use one as a drain bucket and keep the other filled with clean fluid till the old fluid line starts looking red (while shifting through all the gears of course). Anyone see a reason this won't work nicely if I make sure to keep the clean fluid bucket above the level of the transmission so it doesn't have to pull uphill?
 
kastein said:
The garage I used to work at used a machine that connected into one of the tranny cooler lines, measured the quantity of fluid coming out, and pumped in the same amount going back in (you didn't even have to connect the lines carefully, it figured out which one was pumping and auto-switched the lines internally if you had them swapped) - as I don't have 7 thousand dollars on hand to buy such a machine, I've been considering using a pair of 5 gallon pails to do the same job in a more ghetto fashion - use one as a drain bucket and keep the other filled with clean fluid till the old fluid line starts looking red (while shifting through all the gears of course). Anyone see a reason this won't work nicely if I make sure to keep the clean fluid bucket above the level of the transmission so it doesn't have to pull uphill?
Click to expand...
why not make a ghetto flush?
video it and post it on youtube
 
I've heard that the pump in the tranny pushes the fluid toward the radiator cooler, but does not also suck it back. To return, the fluid is pushed along by the output line. You'd literally have to have the supply of new up above, and figure a way to have it flow back at approximately the smae rate that it's pumping out. How about a small drill powered pump? A variable speed cordless. You could regulate the fresh going in by what you see coming out.
 
BTW, Kastien, you mentioned shifting thru the gears while it's running. Unless it's driving, only first will catch if you put it in Drive. But, cycling between Reverse and Drive should do what you're suggesting. How about lifting the rear wheels off the ground, after having first secured the vehicle. Just letting it idle in Drive will get it to at least Second gear. Just be careful!
 
not a total hijack, but along the same lines, what atf (dexIII) is the best? i heard amsoil mentioned, any others?
 
heyhar said:
I've heard that the pump in the tranny pushes the fluid toward the radiator cooler, but does not also suck it back. To return, the fluid is pushed along by the output line. You'd literally have to have the supply of new up above, and figure a way to have it flow back at approximately the smae rate that it's pumping out. How about a small drill powered pump? A variable speed cordless. You could regulate the fresh going in by what you see coming out.
Click to expand...
Yeah that's actually exactly what I'm worried about. We'll see I guess, unless an AW4 guru comes along and clears things up.

heyhar said:
BTW, Kastien, you mentioned shifting thru the gears while it's running. Unless it's driving, only first will catch if you put it in Drive. But, cycling between Reverse and Drive should do what you're suggesting. How about lifting the rear wheels off the ground, after having first secured the vehicle. Just letting it idle in Drive will get it to at least Second gear. Just be careful!
Click to expand...
Considered... not sure I want to risk this though! I might do it while I'm doing my SYE (while the driveshaft is dropped), that way there wouldn't be any way for it to get me in trouble at all.
 
dieselenthusiast said:
I just did my second transmission drain and fill today. It’s a good feeling to see cleaner fluid appear on the dip stick. I don’t have an owners manual, so I was wondering exactly how to check the fluid level. I’ve been checking the fluid by placing my transmission into neutral and checking the dip stick while the vehicle is at idle. Is this correct?
Click to expand...

run the engine for a good 10 minutes (drive it or idle, doesn't matter), and then check the fluid in park.
 
ehall said:
run the engine for a good 10 minutes (drive it or idle, doesn't matter), and then check the fluid in park.
Click to expand...
The tranny dipstick in mine says to check in neutral, might be model year specific but I doubt it. Most vehicles say park, but every Jeep I've seen suggests neutral.
 
General rule on this stuff is do not flush unless it was flushed at previous service intervals. Also you need to be really cautious with transmissions that have been generally neglected. There can be a lot of sediment in old transmissions, and new fluid has fresh detergent that will kick that crap loose. A flush does a full fluid replacement which is a pretty big shock to the system. On an old tranny with dead fluid it's too much to ask.

Best thing to do drain and replace a couple of quarts two or three times, then drop and replace the filter, and refill with more fresh fluid. Drain and refill again if you want to
 
Dexron III. NEVER ATF or ATF+4
 
Dexron III only, got it.

Definitely need to do this, trans has 78k on it and am pretty sure the previous owner never changed the fluid.

What is the capacity? Roughly 3.5-4 qts if only draining and refilling?
 
something like that. I dumped 5something quarts into mine after replacing the cooler lines and draining the cooler as well, and it was only a little overfilled.
 
SeeJay said:
I am new to the AW4 but what fluid is recommended for these transmissions?
Click to expand...
If it's a newer model with < 100K I suggest using ATF+4 synthetic.
My '01 has been using it since new and it shifts as well as the day I bought it and now has over 100k
If it has a lots of miles and has not been well maintained it's probably best to use DexronIII
 
sbxj said:
If it's a newer model with < 100K I suggest using ATF+4 synthetic.
My '01 has been using it since new and it shifts as well as the day I bought it and now has over 100k
If it has a lots of miles and has not been well maintained it's probably best to use DexronIII
Click to expand...

care to elaborate why?
 
sbxj said:
If it's a newer model with < 100K I suggest using ATF+4 synthetic.
My '01 has been using it since new and it shifts as well as the day I bought it and now has over 100k
If it has a lots of miles and has not been well maintained it's probably best to use DexronIII
Click to expand...

As Chrysler specifically prohibited the use of ATF+4 in the AW4 through mid 2006 I doubt your 01 has had ATF+4 since it was new, as it would have been factory filled with Dextron III.
 
Amsoil ATF meets the specifications and works really well.
 
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