If the clutches have worn down completely the clutch material debris and grit that will be in the fluid will often give enough friction for the clutches to work (for awhile). The myth comes from after changing fluid the tranny slips....but chances were that it was going to fail soon anyway.

 

Here is when NOT to change the ATF..

There are several parts in the tranny that have "lining" or a clutch type material. Over time, this WILL wear off and be suspended in the fluid.

On an abused tranny with dark brown fluid, all of the friction material is IN THE FLUID instead of attached to various parts.

Changing the fluid, removes the friction material completely from the tranny and causes it to slip.

That's why flushing sometimes causes the transmission to die.

If your fluid is still red and doesn't smell TOO bad, you can simply change the fluid a few times.

Bonus that the AW-4 has a drain plug.


Over the years, I have found the additive Trans-X to save my bacon. My dad swore by it and it does give a few more miles to abused transmissions that have friction material/leak problems until a proper repair can be made.

 

If this is the case then it will die VERY soon anyway!

 

Unless there's some magic going on in a Jeep transmission that doesn't happen in anybody else's, I'd change it. I did mine when I bought my 1999, with 133k on it, the fluid was getting brown and starting to smell burnt. When that happens, the pH changes to acid, with the heat generated in the torque converter, eats away at the fins and soon you need a transmission. 10 years or so ago, auto manufacturers started claiming they were using "lifetime" ATF and coolant. There's no such thing. They count on any major repair after 100k making you trot in to the dealer's to trade in.

 

Did you mean to joke that the transmission is between the engine and transfer case? That pretty funny.

 

ATF-4 unlike other tranny fluids will turn brown without being bad. The color dye is weak, Chrysler has a TSB stating this. They say to change by mileage and disregard color unless burn't.

 

Here's my problem with that theory: Let's say I maintain my trans over the years (change ATF on a regular basis). As the clutch plates/bands slowly wear, and the material is suspended in the ATF, then each time I change the ATF, that material is drained out.

Now, lets say that my friend has an identical trans, but he never changes his ATF. According to your theory, his trans will outlast mine. Since his ATF still has all the worn-off friction material in it, his trans will be less apt to slip than my properly-maintained trans with the clean (no friction material) ATF.

 

I love it.

 

I've only heard not to power flush it. Dropping a pan and replacing filter and oil is fine.... It's when you flush it, the new fluid getting flushed through can pick up tiny pieces or metal fuzz from the pan and push it through the trans... Getting deposited in sensitive areas.


This is what I heard growing up with cars... Not sure if its 100% accurate

 

That actually makes sense lol my uncle did a trans fluid change in his s10 and it had over 200000 miles and hadnt had a fluid change since 75000 and dont believe he has had any issues that I know of but I just thought maybe he got lucky.

 

Thanks to everyone for the great advice. I decided against flushing the system. I drained the fluid out of the pan, and replaced with 4 quarts of Dex/Merc. I plan on doing this two more time, after a week of driving in between. After the third time, I will add a bottle of Lucas Transmission "Stop Slip".

The fluid I drained out was reddish brown in color. Even after just the first of the three drains, I can already tell its shifting smoother.

Thanks again.

 

P.S. also planning to drop the pan and change the filter and gasket after the third drain.

 

Wouldn't bother, and I wouldn't use Lucas. The aW4 is one of the heartiest trannies ever built.

 

Bought my 98 with 158,000 mi on it. Trans shifted fine. Fluid was red and a little dirty, but smelled fine. Next 8 oil changes (3,000 mi) I dranied and added 3 qts Dexron 3. Maybe overkill, but if you do the math, it's over 99% fresh fluid. No need for a power flush. Now, with over 201,000 mi trans works perfect and the fluid is like new.