serket's-xj

Hello all, I'm wanting to know the best way to go about changing my transmission fluid and/or filter. I've a 98 XJ with the AW-4 transmission. I've had said XJ for almost 2 years and she has a little over 198k on the odometer. I'm not sure if the PO ever had the fluid changed, but my guess is probably yes he did. The transmission works and shifts perfectly so far as I can tell, but I've put nearly 30k on her since I bought her in 2012 so I figure it's time. My main concern is what I have read already about seals leaking and debris being loosened and then floating around in the tranny after the fluid is changed. So to change fluid or not to change fluid, that is the question.

Firestorm500

If you want to change it, the best way seems to be to drain and refill 3 separate times (by dropping the pan). Then drive it for a while before doing the second and third changes.

It seems to be less of a shock to an old transmission that way.

SteveMongr

..And, use only Dexron/Mercon III that's Dex/Merc3 on the AW4.
only,only,only!

dmill89

Why drop the pan? The AW4 has a drain plug.


If you do want to change the "filter" you will need to drop the pan once (probably best to do before the final refill so you have nice clean fluid and a nice clean filter) but the "filter" is really just a screen and there is no need to or specified interval to replace it unless you are have having issues.


If the fluid is relatively clean one drain and fill will likely suffice (this replaced approx. 1/2 of the fluid) this is what the manual specifies as normal maintenance every 30k mi (or 12k mi if you meet the "severe-service" criteria). If the fluid is dirty it may take multiple changes. Drain, refill, drive 100 mi or so and repeat until the fluid is bright red like new fluid out of the bottle.


That changing the fluid is bad for a high-mileage transmission is a pure myth, a pressurized flush can knock stuff loose but drain and fills or a "fluid-exchange" (which uses the transmission's own pump to pump out the old fluid and the new in) is perfectly safe. By far the worst thing you can do is continue to run old/dirty/burnt fluid.


And as SteveMongr pointed out only use DexronIII/Mercon no matter what the parts store guy tries to tell you. The AW4 is NOT a Chrysler transmission and DOES NOT take ATF+4.

Firestorm500

Does Dextron VI interchange with III?

serket's-xj

DexronIII it is then, but how much should I buy at the parts store then, i.e. quarts, gallons, tanker truck?

Firestorm500

Found this:
From a GM tech bulletin:

Although DEXRON-VI (fig. 1) was introduced into production starting with 2006 model year vehicles (see bulletin 04-07-30-037D), there are still some misunderstandings about it. Here are some facts to help clear up these misunderstandings.
Since GM introduced the first service-fill specification for automatic transmission fluid (ATF) in 1949, it has been necessary periodically to upgrade the specification as part of a continuous improvement strategy. The upgrading process ensures that available service fill fluids are of an appropriate quality for use in transmissions that have been designed around the improved factory fill fluid performance.

IMPORTANT: As with previous upgrades, DEXRON-VI fluids are designed to be backward compatible with earlier transmission hardware. But more important, earlier type fluids are NOT FORWARD COMPATIBLE with transmissions that were designed to use DEXRON-VI.
DEXRON-VI can be used in any proportion in past model vehicles equipped with an automatic transmission, in place of DEXRON-III (for instance, topping off the fluid in the event of a repair or fluid change). DEXRON-VI is also compatible with any former version of DEXRON for use in automatic transmissions.

TIP: Simply topping off the fluid is adequate, but a full drain and replacement is preferred, to obtain the full benefit.

IMPORTANT: DEXRON-VI Automatic Transmission Fluid (ATF) is the only approved fluid for warranty repairs for GM transmissions requiring DEXRON-III or prior DEXRON transmission fluids.

TIP: Any vehicle that previously used DEXRON-III for a manual transmission or transfer case should now use p/n 88861800 (88861801 in Canada) Manual Transmission and Transfer Case Fluid. And power steering systems should now use p/n 89020661 (89021183 in Canada) Power Steering Fluid.

TIP: Since some early bulletins were issued, further validation has taken place and certain transfer cases and manual transmissions now DO use DEXRON-VI, so it's important to refer to the owner manual for appropriate recommendations.
All licenses for DEXRON-III expired at the end of 2006 and will not be renewed. Fluids sold in the market after that date bearing claims such as "suitable for use in DEXRON-III applications" or similar wording should be avoided, because 'DEXRON-III' fluids are no longer checked and policed by GM and therefore may not be the originally tested and approved formulation.

ADVANTAGES OF DEXRON-VI

GM uses an ATF for factory fill that provides significantly improved performance in terms of friction durability, viscosity stability, aeration and foam control, and oxidation resistance. In addition, the fluid has the potential to enable improved fuel economy and extended drain intervals. The service fill specification for a fluid meeting these standards is designated as DEXRON-VI.

When compared with earlier automatic transmission fluids, DEXRON-VI offers these improvements and benefits:

- enhanced performance of both new and older transmissions
- longer ATF life (160,000 km/100,000 miles normal, or 80,000 km/50,000 miles severe). It is important to refer to the owner manual because certain vehicles recommend a normal service drain interval of 150,000 miles (240,000 km).
- consistent shift quality throughout the life of the transmission
- extended transmission life.

To achieve these benefits, DEXRON-VI offers significant improvements in these operating characteristics:

Friction Stability (improved 100%) -- Friction describes how the fluid behaves when transmission clutches or bands are engaged. A fluid with poor friction characteristics leads to grabbing, chattering and slipping (fig. 2).





DEXRON-VI also offers a 120% improvement in clutch durability (fig. 3).




A DEXRON-III
B DEXRON-VI

A Clutch operated with DEXRON-III
B Clutch operated with DEXRON-VI

Viscosity Stability (greatly improved) -- Viscosity is a description of how thick or thin a fluid is at various temperatures. In a hydraulic system, components can function sluggishly or improperly when viscosity is wrong. As determined by comparison testing (fig. 4),



DEXRON-VI maintains an almost constant viscosity over time, while the viscosity of DEXRON-III degrades considerably.

A DEXRON-III
B DEXRON-VI

Foaming Resistance (improved 150%) -- Automatic transmission fluid may contain air in three forms -- dissolved, entrained (aeration) and foam. Oil containing air doesn't do anything very well -- lubrication is affected, heat transfer in affected and pressures are unstable. Anti-foam additives are used to control and limit the effects of air in the fluid (fig. 5).



A DEXRON-III foam test
B DEXRON-VI foam test

Oxidation Resistance (improved 100%) -- Oxidation describes the length of time it takes for a fluid to reach the end of its useful life. Oxidation generally occurs more quickly at higher temperatures (fig. 6).




And oxidation has an effect on how long a fluid can be used before replacement is necessary.

A Aftermarket fluid oxidation test
B DEXRON-VI oxidation test

TIP: Just because another auto maker does not require use of DEXRON-VI, this does not imply that their required fluid is in any way inferior to or better than DEXRON-VI. It simply means that the other auto maker has established its own, unique fluid requirements. Their transmissions may be built with different materials, and may be designed to perform in different ways, neither of which is necessarily inferior to or better than GM's transmissions, just different. Variables include the material used for friction surfaces, the material used for reaction surfaces, the types of control mechanisms and the characteristics of the factory fill fluid. This means that each manufacturer must tailor their transmission fluid requirements to meet the needs of their own transmissions. And a fluid may cause entirely different performance when installed into transmissions of different designs.

COUNTERFEIT PRODUCTS

Beware products that claim to be DEXRON-VI but are not; for instance, some products claim to be multi-purpose. And beware the products which claim to provide DEXRON-VI characteristics when added to other ATFs. Unlicensed products have not been tested by GM to determine whether they meet GM's specifications.

ADDITIVES

DEXRON-VI is formulated to meet and exceed GM's specifications and requirements. Additives are not needed and are not recommended.
The best thing that can happen when using an additive is that it will do nothing. At worst, an additive can ruin the transmission.

DEALING WITH CONTAMINATION


Anything but DEXRON-VI in the automatic transmission is considered a contaminant. Typically, a customer or other service facility may add fluids other than DEXRON-VI. This includes aftermarket additives -- they are not needed and should not be used. In case like this:

- drain the transmission fluid
- flush the system with DEXRON-VI (NOT solvent)
- fill the system with the correct amount of DEXRON-VI.

FLUSHING

Many aftermarket flushing systems rely on solvents, which essentially may be considered contaminants. The effects of these contaminants may lead to transmission failure.
Refer to bulletin 02-07-30-052E and also document 1601517 for the complete story on using the Automatic Transmission Oil Cooler Flush And Flow Test Essential Tool J 45096 TransFlow. Here are some highlights.
Two significant features of the J 45096 are (1) that it uses DEXRON-VI, not solvent, as a flushing agent, and (2) that it injects high pressure air into the fluid stream to agitate the ATF oil to enhance removal of contaminated ATF and debris.

TIP: It is important to flush the system in both directions (back-flush and forward-flush). There are instructions in SI to explain how to make the proper hookups for both directions.
There are also instructions in SI explaining which adapters to use for various transmissions.

My comments: Obviously, it talks about GM transmissions. But it looks like we need to consider going to Dextron VI when we do our changing now. It appears to be superior in every way to III.

In addition, the quality of III is not being monitored, at least by GM, because the license expired. So anybody can make any claim they want to about III. We may not be getting what we think with III now.

dmill89

In GM vehicles yes, but I wouldn't recommend it in the AW4. Dexron VI like most newer transmissions fluids is thinner than Dexron III, both due to being full-synthetic and to improve fuel economy. Thinner fluid can potentially drop line pressure and cause slipping/excess clutch wear in a transmission not designed for it, especially on a high-mileage transmission. GM made sure Dexron VI was backward compatible with their own transmissions but did not design it for or test it with non-GM transmissions using Dexron III


Aisin (the manufacture of the AW4) still recommends only Dexron III/Mercon, which is the best way to go.

Firestorm500

I have not used it in a transmission yet. I plan to change the fluid in my '92 when the weather warms up some. I guess I had better stick with III just to be safe.

I did put VI in a transfer case in my '87 and my '97 last time I changed them. They seem to be doing fine.

Pelican

The fact that an ATF is labeled as DexronIII/Mercon compatible does not mean that it is not a full synthetic.

Been using a full synthetic DexIII/Mercon for 7 years(as have many others) with no problems.

EZEARL

If you go the drain plug route you'll need about 3.75 qts. How much to buy will depend on how many times you'll have drain the tranny until the fluid is like new. Mine was a light brown and took three drains. I had bought 3 gal.

SteveMongr

I usually buy a case of 12 from NAPA, house brand.
As for mixing fluids, not in the AW4. No Dex 4 or 6, only 3.

Regarding the above service bulletin, did not read it word for word but I understand and have heard before what it's getting at.

That bulletin is specific to GM and/or Chrysler products.

The AW4 is NOT a GM product!
Designed and manufactured by Asin-Warner. The manufacturer specifies DeX/Merc III only, that has not changed.

Also, GM does not manufacture Dex/Mec III and they obviously want to specify what they do make so they can sell it.

Too many times, too many people have used different fluids and ended up with AW4 issues.

Stick with Dexron/Mercon III. And please cross reference this info. It is not just my opinion.

SteveMongr

Better safe than sorry..
As for the TC it just likes red fluid so you will be fine. But the 247 and 249 on the Grand's is a different story. One has a progressive coupler, the other is viscous. Good thing we have real differentials in the 231 and 242.

Firestorm500

I should mention that the '97 is actually a Grand I am fixing up as a DD for my daughter. It has Select-Trac, but it is selectible and not All Wheel Drive all the time.

I hope I didn't mess up by putting Dex IV in it. What came out was really nasty and not much volume. Anything would have been an improvement. I don't think it had ever been changed. I had to use breaker/cheater bars on the plugs to break 'em loose.

Bobolink

Well, just to add my 2¢, I've used nothing but Amsoil Synthetic Universal Xmsn Fluid in my AW-4 equipped MJ since I can remember. At 24 yrs old and 255K miles, it's still pulling my 4000# boat 500 miles every other month, still shifts like it did when it was young, still seemingly bulletproof. I've just changed fluid and filter every couple years since it was new. It's definitely aging with more grace than I am.