why not Mobile 1 ATF in the AW4

[BrettM]

a couple posts down several people mentioned that it is a bad idea to put Mobile 1 ATF in the AW4.

i just swapped in an AW4 (replacing Peugoet) and put about 6 quarts of the stuff in, i thought it was the good stuff? :huh:

so why not? how urgent is it that i change the fluid to something else?

[martin]

I lost 3 mpg when I put Mobil 1 ATF in my AW4 transmission of my 88 XJ. After changing lots of sensors I realized I lost my MPG after the Mobil 1 atf.

I took my XJ to the dealer and had the transfusion done on the transmission.

There is a TSB from the late 80s or early 90s which said to only use Dextron which has the certification number on the bottle. The Mobil 1 ATF says it is Dextron III but no cert number on the bottle, also no cert number on the material data sheet on their web site.

It up to you what you want to do but I hightly recommend you get the Mobil 1 out of the transmission.

I will say I have had no problems with Mobil 1 ATF in my NP 231 transfercase, only problems in my AW4.

[BrettM]

3mpg would definitely be worth getting it out, especially since i'm going to drive it from Michigan to Cali (2200 miles) in 3 weeks. would it need to be flushed or just drain the pan and fill with regular. i only put 6 in, and if the tranny is totally dry, i think it's supposed to take 16, so i'm guessing there's 10 quarts of the right stuff in there.

has anyone else experienced a gas mileage difference? what could cause that? i haven't noticed much, but i did change from a 5 speed, and swapped the 4.10s for 4.88s pretty soon afterwards too.

[RichP]

Not to scare you but people have had varying results with synthetic in the auto trannies, they have run the whole gamut from 'wonderful' to 'burned up my tranny in less than 500 miles' and everything in between. I would recommend that if you think you are having ANY tranny problems, stop, drain the Mobil-1 out and put in the recommended fluid. You will have to do this several times, drain and refil, drain and refil to get most of it out. A lot of it stays in the tranny when you drain the pan so the only way to get it all out at once is to have the flush done. I think alot has to do with the condtion of the tranny when it was added, you might get lucky but keep an eye on it and watch the fluid level. It tends to find any bad seals no matter where it is, engine, TC or diffs and work it's way out. No matter what the jury is still out on whether it is good stuff or not for AT's....

[Bryan C.]

I'd have to agree on using standard Dexron fluid. Synthetic is just too darn slick and it can get past the clutch and piston seals and cause problems internally. Not to mention leak past all the outer seals too. Chrysler themselves are very picky about what fluid to use in the AW4. The ATF+4 is 75% synthetic and they expressly state not to use it in AW4 transmissions. The fluid capacity specs I just found said 8.45 quarts total. Just draining and refilling the pan account for only about 3-4 quarts, the rest is in the torque converter. If it was my Jeep, I would go out and buy a case of Dexron fluid. Drain and refill the pan, then take loose the trans cooler pressure line and run the engine while pouring fluid into it. Just be careful not to run it dry, you can shut off the engine if you can't get the fluid in as fast as it is coming out. This is basically what the transmission fluid transfusion machine does, just without the mess. Run the whole case of fluid through and all the Mobil 1 should be gone. The pump will flow a minimum of 1 quart every 20 seconds, mine flow checked at a rate of about 1 quart ever 15 seconds. Having a buddy with a watch and to turn off the engine will help out. Or you can just take it somewhere and have it done for you. Either way, it should be done.

Bryan

[BrettM]

what's a typical cost to get it done?

[triple 4]

Here is an other thought, have you ever herd of, or tryed to run amsoil in your trans? I'm running it in a 91 ford 460 with a E40D thats a rebulit trans, I also have a 2000 power stroke that when I bought it the trip computer read 12.3 avg/mpg now i do not know how true it is but I switch the motor trans and the tcase over to amsoil and now it read 16.1 avg/mpg. I mave not noticed any problems with the trans, and there is not going to be any. Plus amsoil has ATF that meet the specs on an Alsion trans, behind the durmax. Plus a power shift ATF used in monster trucks and RVs, I have hurd that Mobile 1 is poor oil, I also have some info on test that have been done on Mobile 1 and Amsoil. Plus Amsoil stands behind what they say and test. Ask mobile 1 how they stack up next to Amsoil. Let me know if you what the Info. Triple 4

[RichP]

Here is an other thought, have you ever herd of, or tryed to run amsoil in your trans? I'm running it in a 91 ford 460 with a E40D thats a rebulit trans, I also have a 2000 power stroke that when I bought it the trip computer read 12.3 avg/mpg now i do not know how true it is but I switch the motor trans and the tcase over to amsoil and now it read 16.1 avg/mpg. I mave not noticed any problems with the trans, and there is not going to be any. Plus amsoil has ATF that meet the specs on an Alsion trans, behind the durmax. Plus a power shift ATF used in monster trucks and RVs, I have hurd that Mobile 1 is poor oil, I also have some info on test that have been done on Mobile 1 and Amsoil. Plus Amsoil stands behind what they say and test. Ask mobile 1 how they stack up next to Amsoil. Let me know if you what the Info. Triple 4

Hmmm, so do you run amsoil tranny fluid in your auto tranny XJ ???

[martin]

If you pull the drain plug you will get 3 quarts out of the transmissoin. You can do this several times. My AW4 manaual says the capacity from "dry" is 13 quarts. My guess is the volume of the lines and trans cooler is not included in that number. When I changed my transmission filter I put in 4 quarts of Mobil 1 ATF then a few days later I put in 3 more quarts of ATF. I pulled the oil pan drain. I was not going to pull the pan again to get an additional quart.

I went with the flush because the "blended" ATF would be pumped out and only nomral Dextron would be dumped back in. I think they change 12 quarts in a flush, so 12 quarts of blend out, 12 quarts of normal back in. I could figure out what it would take to change it out but it more complicate that you would think. When I was in college we'd have the tank full of sea water and a fresh water hose dumps water in and there is a hose out taking the blend. We had to figure out how long before fresh water was coming out of the tap.

The pulling the drain and filling with 3 quarts is similar to the problem. I think as a general rule it will take 300% of the volume to get it "flushed" that way.

I had mine done at the dealer, it only took the one flush to solve the problem. I told the mechanic what I had done so he would know it was not "routine maintenance" but a flush to get out "suspect" fluid.

[triple 4]

oh ya sorry, I have a 91 jeep cherokee with an aw4 and I did the pan and filter I used it to, all and all good oil.

[L92XJ]

I did the tranfusion to AMSOIL ATF on my 92 which had 170K miles on it at the time. That was about 9 months and 5k miles ago ( now at 175K). Didn't notice any changes at all in performance (shifting or gas mileage) and also don't have any leaks.

[Bryan C.]

what's a typical cost to get it done?


We used to do the fluid exchange service at the dealer I work at. It used to run somewhere close to $200+ dollars. It works good. What I described above with allowing the trans to pump out the old fluid into a drain via the disconnected cooler line is pretty much how the flusher worked. We just connected the machine in series with the cooler circuit and pumped the clean fluid back into the trans by the cooler return line while the trans pumped the old fluid out. The only problem I had with it was the machine was supplied to us by a chemical sales company that wanted us to use their $50 flush and conditioner fluid additive kit. We were having problems with techs not being able to flush all of the "flush additive" from the system and it was causing torque converter problems. Mostly a bad shudder when it engaged and disengaged. We started just running it with straight fluid, but the chemical company pulled the machine out due to lagging sales of its trans service chemical kit. It really works well, but is quite expensive.

Bryan

[egon]

I also run Amsoil ATF in my AW4 and have had no issues, nor loss of fuel mileage. I started off swithing to M1 ATF but found the Amsoil to be cheaper. Synthetic ATF in my AW4 for 50k miles, no issues here. I'm at 110k now.

--Matt

[BrettM]

any more opinions on this?

[5-90]

The consensus is that the synthetic oils are actually too good for the clutches, and they don't "stick" like they're supposed to. If you've never taken an auto apart, it's FULL of clutches and gears - the AW4 has something like 24 frictions discs, IIRC. Since they are actually bronze, there is a threshhold value for friction reduction before you lose power/efficiency (BTW - it is the slipping of the clutches that causes the loss of mileage, and the transmission operating temperature will rise as a result. If you don't have a divorced cooler setup, this will manifest as increased engine temperature as wll - but only slightly.)

Also, as I recall from the AW4 service manual, the "service fill" (pan only) is four quarts, and the "overhaul fill" (entire box including TC) is eight quarts of fluid. If you just pull the plug and refill, you will drain out slightly less than four quarts of fluid, and the small extra amount leftover when you refill won't hurt anything.

From what I've been hearing about the "transfusion machine" service, I may build one for myself once I bother to figure out how (I just haven't been arsed to yet...) It would be nice to change ALL the fluid once in a while...

5-90

Oh - and I'd get rid of the synthetic stuff. I've done more auto transmission work than I care to admit to, and they really are picky devices...

5-90

[BrettM]

i'm pretty much broke, but certainly fluid is cheaper than a new tranny. I figure it already has 25% or more of non-synthetic. How many quarts should I buy to run through it?

8 quarts -37.5% synthetic
16 quarts -18.75% synthetic
24 quarts -9.375% synthetic
etc.

how far should I go? cost is important. Also, what fluid? any fluid that is Dsxron III? looks like NAPA has that for $1.39 per quart, not bad.

[BrettM]

i'm pretty much broke, but certainly fluid is cheaper than a new tranny. I figure it already has 25% or more of non-synthetic. How many quarts should I buy to run through it?

8 quarts -37.5% synthetic
16 quarts -18.75% synthetic
24 quarts -9.375% synthetic
etc.

how far should I go? cost is important. Also, what fluid? any fluid that is Dsxron III? looks like NAPA has that for $1.39 per quart, not bad.


anyone?

[BrettM]

come 'on, someone please? i need to know how much to buy and if i'm fine using the $1.50 stuff

[5-90]

Pretty much all I use is Valvoline (should be pretty close to $1.50 per.) How much? I don't know what your current means are, but there will be a point of diminishing returns if you keep doing partial changes - and flushing out the torque converter (which is FULL of fluid!) is only doable under pressure and operation (think: transfusion machine.)

Figure your percentages are a bit low for flushing out - add an "error factor" of 10% of the result or thereabouts. Probably two to three service changes will get you down to where you won't hove too much trouble, but I won't swear to it.

As far as what fluid to use, pretty much any name brand (except Pennzoil or Quaker State!) that carries DexronII or DexronIII specification will serve well.

5-90

[martin]

When buying Dextron III ATF make sure the Certifiation number is on the back. It should be something like D-3XXX. Look at all the bottles of AFT at teh store and go with only the brands that have the certification number on the bottle.

For discussion sake lets say your AW-4 have a volume of 13 quarts. I got this number form the AMC/Jeep AW-4 overhaul manaul I purchased for my 88 XJ. Also lets say you have all 13 quarts Mobil 1 ATF. I also take it you will only be draining out of the pan pain hole not pulling the pan. I get 3 quarts when using the drain, 4 quarts when I pull the pan. Also run the engine for 5-10 minutes between fillings to get a good mixing fo the fluid. You may want to set the parking prake and let it idle in neutral instead of park. You get full pump pressure in neutral, paritial pump pressure in park.

Start
13 qts Mobil 1,

Change 1
remove 3 quarts, add 3 qts - 77% Synthetic

Change 2
remove 3 quarts, add 3 qts - 59% Synthetic

Change 3
remove 3 quarts, add 3 qts - 45% Synthetic

Change 4
remove 3 quarts, add 3 qts - 35% Synthetic

Change 5
remove 3 quarts, add 3 qts - 27% Synthetic

Change 6
remove 3 quarts, add 3 qts - 21% Synthetic

Change 7
remove 3 quarts, add 3 qts - 16% Synthetic

Change 8
remove 3 quarts, add 3 qts - 12.3% Synthetic

Change 9
remove 3 quarts, add 3 qts - 9.43% Synthetic

Change 10
remove 3 quarts, add 3 qts - 7.25% Synthetic

Change 11
remove 3 quarts, add 3 qts - 5.6% Synthetic

Change 12
remove 3 quarts, add 3 qts - 4.3% Synthetic

Change 13
remove 3 quarts, add 3 qts - 3.3% Synthetic

I ran the numbers using Excell. If you had ONLY 6 quarts of mobil 1 AFT in the 13 quart trans it would be more like this:

Change 1 - 35% Synthetic
Change 2 - 27% Synthetic
Change 3 - 21% Synthetic
Change 4 - 16% Synthetic
Change 5 - 12% Synthetic
Change 6 - 9.6% Synthetic
Change 7 - 7.36% Synthetic
Change 8 - 5.66% Synthetic
Change 9 - 4.35% Synthetic
Change 10 - 3.35% Synthetic
Change 11 - 2.58% Synthetic
Change 12 - 1.98% Synthetic
Change 13 - 1.52% Synthetic

With either situaion - 13 or 6 qts of Mobil 1 it will take 9 or 6 changes of fluid to get below 10% synthetic. You will need 18-24 quarts to get 90 percent of the Synthetic out of the transmission.

I do know one 12 quart flush as the dealer did solve my MPG problem. This may save you time and the burden of disposing of 6 gallons of ATF. I like the idea of the transfusion, all that "blend" is pumped out and only non-blend is returned. You will have the torque converter flushed when you are done!

[5-90]

Not to disparage Martin's maths (or his ability to run Excel, which is probably better than mine) but remember that the world is not a 100% efficient place, which is why I mentioned the error in calculations before. However, the 10% threshhold sounds reasonable, and you are still better off forking over for the transfusion than trying to dispose of all that fluid (that reminds me, I've still got 10 gallons of waste oil to get rid of...)

He is entirely correct on the running of the box to mix the fluid, and I'd add to that that you will want to sit there with your foot on the brake and run the transmission for at least ONE FULL MINUTE in EACH shifter gear range, so you can get the stuff that's in ALL the valve body passages involved. If you've ever overhauls an automatic transmission valve body, you know what I mean. If you haven't, just trust me on this...

Martin - which AW4 manual did you get? I've got the one from ATSG, which agrees with my 1989 FSM on the 8/4 quart fill levels. I'd like to find out more - and if you have a scanned copy, perhaps we could swap?

5-90

[BrettM]

i put 6 quarts mobile 1 in, so it looks like i'll need about 20 quarts, at $1.50 that's only $30. i'll call some places and see what it would cost to get a flush. and disposing of oil is no problem, I use my school's maintenence garage and they have a big drum I can dump it in.

i figured it would be best to run the tranny through all gears between fills, thanks for that tip.

[RichP]

Oil disposal, heck since my friend got one of those waste oil heaters he loves to see me come in from a weekend orgy of vehicle maintenance. In our case thats a quick 5 gallons of 'liquid gold' for that 400 gallon tank of his. I guess S calif does not have that opportunity..... He also knows I would not mix it with anything else, that 'other stuff' I drop off at the local town recycling yard as needed.
Nobody wants my old Coleman stove fuel though.

[techno1154]

Isn't the Amsoil ATF synthetic? If this is true how come those who uses it do nto have problems? I am trying to get some here in Miami but cannot find a dealer or store that has it. I want to see if this could cure my AW4 stick when hot.

[martin]

I look in my manual and found it to say 8 litres/ 8.75 quarts for the transmission.

I am not sure where I saw it, thought it was www.alldatadiy.com but it only shows refill of 4 quarts.

I believe alldata changed the information it gave 3 numbers what I recall and they were 8, 12 and 13 quarts depending on what service you did.

8 was for the transmission pan removal
12 I do not recall
13 was a completely dry system, new trans, lines and radiator.

Remember those fluid lines do retain fluid and the the trans cooler in the radiator also holds a large volume of fluid. Just cause the transmission holds 8.75 quarts not 8 quarts. My source is the AMC/Jeep AW-4 transmission overhaul manual published in 1986 by AMERICAN MOTORS CORPORATION.

I also went to the effort to show the diminishing return on changing the fluid. I guess I should of stated that table assumed "full" mixing of the fluid.

I tried to pass on my "lessons learned" by filling my transmission with 7 quarts of Mobil 1 ATF. You will use less fluid and have better results if you have the transfusion. You said you are going to california soon. I worry you will quit at the 4th change and say "good enough" then you still have the lower MPG I lived with for close to a year.

You could ignore our advice and drive it to see what happens. Just trying to pass on the transfusion is the best method to fix this problem. Sometimes we have to pay a professional to fix our mistakes.

[Bryan C.]

This is what I found in the Chrysler TechConnect website:
REFILLING AFTER OVERHAUL OR FLUID/FILTER CHANGE
The best way to refill the transmission after a fluid change or overhaul is as follows:

If transmission has been overhauled, install transmission in vehicle.
Remove dipstick and insert clean funnel in transmission fill tube.
Add following initial quantity of Mopar Dexron IIE/Mercon to transmission:
If fluid/filter change was performed, add 4 pints (2 quarts) of fluid to transmission.
If transmission was completely overhauled and torque converter was replaced or drained, add 10 pints (5 quarts) of fluid to transmission.
Remove funnel and install dipstick.
Operate vehicle until fluid reaches normal operating temperature.
Apply parking brakes.
Let engine run at normal curb idle speed, apply service brakes. Then shift transmission through all gear ranges and back to PARK (leave engine running)
Remove dipstick and check fluid level. Add only enough fluid to bring level to Full mark on dipstick. Do not overfill. If too much fluid is added, excess amount can be removed with suction gun and plastic tubing. Tubing only has to be long enough to extend into oil pan.
When fluid level is correct, shut engine off, release park brake, remove funnel, and reseat dipstick in fill tube.


I recently swapped out the transmission 2 times on my own Jeep recently. Both transmissions were Mopar Remanufactured, and both transmissions took 5 quarts to fill them up. When I service a AW4 transmission at work, all I do is pull the plug and let it drain. The filter is merely a screen that I have yet to see plug up unless the trans has a bunch of clutch material floating around in it.

My question is why not try to flush the trans like I said. You won't do any damage to the trans and you will be much better off this way than tryin to contunally drain and refill the trans. I have done this very same thing on multiple transmissions without any harm. Like I said, this is exactly how the transfusion machine works. Hopefully you can figure this out because I think we are all in a cinsensus about the synthetic not being good for AW4s.

Bryan

[loop]

well...i worked out at Jeep for a good while and taked to several Chrysler Master Techs and every one of them said there would be no problems running synthetic in the AW4. so... 7 years ago ...right before the first Moab run in this clubs infancy....i changed over to all synthetics and have never had any troubles with my tranny. a couple of my friends have run the same combo for years and no problems yet. i run everything from rocks(Rubicon)to deep sand ( Pismo often)...both heat builders and tranny stressors.so for longer than this club has been in existance i've been running synthetic in an AW4....you'd think that if there was a problem it would have become apparent? the only person i've talked to personally that claimed to have problems with synthetic/ aw4 has been Beezil(who's word gets around NAXJA)....but he's just got problems in general so i take that with a grain of salt.

YMMV...but i thought i'd add an alternate viewpoint

[BrettM]

well...i worked out at Jeep for a good while and taked to several Chrysler Master Techs and every one of them said there would be no problems running synthetic in the AW4. so... 7 years ago ...right before the first Moab run in this clubs infancy....i changed over to all synthetics and have never had any troubles with my tranny. a couple of my friends have run the same combo for years and no problems yet. i run everything from rocks(Rubicon)to deep sand ( Pismo often)...both heat builders and tranny stressors.so for longer than this club has been in existance i've been running synthetic in an AW4....you'd think that if there was a problem it would have become apparent? the only person i've talked to personally that claimed to have problems with synthetic/ aw4 has been Beezil(who's word gets around NAXJA)....but he's just got problems in general so i take that with a grain of salt.

YMMV...but i thought i'd add an alternate viewpoint

did you notice any change in gas mileage after the switch?

[defenestrate]

apparently it's been partially covered, but my understanding was that mobil 1 ATF was "dexron compatible" and not actually dexron-certified, whereas some of these other synth ATF options might be. could this account for the difference?

[Dave DE]

One more data point - I've been running Mobil1 ATF for about a year now. No problems, gas mileage is the same.

Dave

[Clean Racing]

Mobil one is a good alternative to the ATF+3 that DMC wants to sell you for your aw4. I on the other hand use nothing but the TOYOTA trans fluid that was in that transmission since it was built by asian/warner in japan. From being an ex Toyota/Lexus tech I have pretty much seen it all with these trannies in the late 80's 4runners. I think that if you actually took the DC atf+3 and the mobil 1 to a lab, the mobil one would outsurpas the atf+3 any day of the week regardless of what dexron rating it has. Maybe something esle is causing the loss of gas milage, or maybe the trans has a problem, and you are now noticing it. Good luck