mercon vs. atf3

[redrockphil]

I recently replaced my radiator. Unfortunately the tranny oil cooler line had a leak and I lost a ton of my old fluid. So, I bought it to the dealer and they flushed the system and replaced the fluid. Its nice and red now. My question is this.... It is recommended that we use mercon/dexron, however, the dealer used ATF 3. I asked him about it and he said that that is what they use all the time. All the Jeeps that some in for tranny service. Does anyone know what the difference is? Can this be bad for the tranny? I mean it feels fine. No difference, it shifts the same.

 

[martin]

Use what your dealer installed in it.

Also what does your owner's manual say for ATF fluid. If it says Dextron III then go back, talk to the service manager and ask why the installed the wrong fluid.

If the manager gives you the "that what we always use" then ask to see the Technical Serivice Bulliten which authorizes the ATF3. If they can not produce a TSB saying to use ATF 3 then have them do a flush with Dextron, make them do it two times to make sure all the ATF 3 is gone. Also this Dextron double flush should cost you nothing because it is their screw up.

Tell the service manager you are doing the maintenance on your XJ per the owner's manual to include the specified fluids. Tell him since they put in ATF3 any Jiffy lube would want to install dextron since that what is called out. Ask him where the placed a plackard on the vehicle saying AFT3 in use.

I had a flush done at my dealer in the past year and the mechanic used Dextron. So my Jeep dealer has Dextron on the shelf.

 

[RINGKONG]

My understanding. is that ALL AW4's use Dextron III and nothing should be used in its place.

the ATF3 is used for ALL Chrysler auto Trannies... the AW4 is not a chrysler trannie..

You should be more worried about the flush than anything..

******PERSONAL OPINION STARTS***********
flushing a high milage tranny is a bad idea.. all the crap that has settled in the transmissions nooks and cranies gets flushed thru the tranny... causing untold heartache.. it may not bite you this time so you may be lucky.

*******END PERSONAL OPINION*******************

 

[martin]

Ringkong,

He already done a flush so can't change that. Then the dealer put in the wrong ATF. How else are you going to change out all the ATF so the right stuff is in there?

My Jeep dealer does transmission flushes. My mechanic told me they dump in this can of stuff, then let the engine idle and bring the ATF to temperature then they do the transfusion. This addative helps clean off the build up. I have seen where it comes out black from some vehicles.

Since I had the flush done the mechanic and I were talking and he told me how he did a flush on a 88 XJ with over 120,000 miles on it. He said it must of been the factory fluid by the color it was when it came out.

I asked the question about doing a flush on a "high mileage/never had the ATF changed" transmission and the mechanic said "it's not a problem the way we do it".

It seems like flushing a transmission and brand of motor oil used is one of those "personal" decisions.

What is the best thing to do since the wrong ATF is already in the transmission and needs to be changed out with the right stuff?

About 2 years ago I put in Mobil 1 ATF in my 88 XJ's AW4. I lost 3 MPG but changed most every sensor before I looked over my maintenance records and concluded my lost of MPG started when I put in the Mobil 1 ATF.

I took it to the dealer to have a flush done and get back to normal Dextron. It solved my lost of MPG! I will say since 1994 when my family acquired this 88 XJ we have done fluid maintenance according to the manual. So my XJ was a maintained XJ, not sure about the "never had ATF changed" XJs.

Martin

 

[RINGKONG]

Ringkong,

He already done a flush so can't change that. Then the dealer put in the wrong ATF. How else are you going to change out all the ATF so the right stuff is in there?

My Jeep dealer does transmission flushes. My mechanic told me they dump in this can of stuff, then let the engine idle and bring the ATF to temperature then they do the transfusion. This addative helps clean off the build up. I have seen where it comes out black from some vehicles.

Since I had the flush done the mechanic and I were talking and he told me how he did a flush on a 88 XJ with over 120,000 miles on it. He said it must of been the factory fluid by the color it was when it came out.

I asked the question about doing a flush on a "high mileage/never had the ATF changed" transmission and the mechanic said "it's not a problem the way we do it".

It seems like flushing a transmission and brand of motor oil used is one of those "personal" decisions.

What is the best thing to do since the wrong ATF is already in the transmission and needs to be changed out with the right stuff?

About 2 years ago I put in Mobil 1 ATF in my 88 XJ's AW4. I lost 3 MPG but changed most every sensor before I looked over my maintenance records and concluded my lost of MPG started when I put in the Mobil 1 ATF.

I took it to the dealer to have a flush done and get back to normal Dextron. It solved my lost of MPG! I will say since 1994 when my family acquired this 88 XJ we have done fluid maintenance according to the manual. So my XJ was a maintained XJ, not sure about the "never had ATF changed" XJs.

Martin

Like I said.. a personal opinion..

the shop has allready stuck in the wrong stuff and flushing it TWICE isn't the way to go..

just leave it in.. and hope for the best. He could take of the output line to the the rad and keep dumping in dextron III while pumping the old wrong stuff out... he would have to do it until the atf3 is out... I wouldn't go this route either it's too risky.

"Not the way we do it" is not a very comforting thing to hear from a mechanic...

 

[redrockphil]

The screwed up part is, they probably never got all the old dextron out. So its probably a mix of the two. I had this done when it had 75,000 on it. I guess I'll have to take it back and get it done right. Such a pain in the arse. I mean, I cant be the only person concerned with the use of a ATF that isn't specified in the manual.

 

[RINGKONG]

The screwed up part is, they probably never got all the old dextron out. So its probably a mix of the two. I had this done when it had 75,000 on it. I guess I'll have to take it back and get it done right. Such a pain in the arse. I mean, I cant be the only person concerned with the use of a ATF that isn't specified in the manual.

I know I would be concerned. especially flushing it yet again.

I am probably making you parinoid... you should be ok.

 

[FatXJ]

Getting it flushed can't be nearly as bad, if at all, as running the wrong fluid in it.

 

[Eagle]

I disagree with Ringkong. DO NOT allow the wrong stuff to remain in the tranny, and DO NOT drive the Jeep anywhere with the wrong stuff in it, except back to the dealer to demand that they flush the tranny and replace with the correct stuff.

As noted, Chrysler transmissions use ATF-3, but the AW-4 uses Dexron/Mercon. If they were the same, the owners' manuals and factory service manuals certainly would not be so specific regarding what to use in the AW-4.

If the dealer gives you any lip, call the Chrysler customer satisfaction hotline immediately, and also report him immediately to whatever agency in your state licenses repair facilities.

 

[RINGKONG]

I disagree with Ringkong. DO NOT allow the wrong stuff to remain in the tranny, and DO NOT drive the Jeep anywhere with the wrong stuff in it, except back to the dealer to demand that they flush the tranny and replace with the correct stuff.

As noted, Chrysler transmissions use ATF-3, but the AW-4 uses Dexron/Mercon. If they were the same, the owners' manuals and factory service manuals certainly would not be so specific regarding what to use in the AW-4.

If the dealer gives you any lip, call the Chrysler customer satisfaction hotline immediately, and also report him immediately to whatever agency in your state licenses repair facilities.

I never said... ok maybe I did.. but I didn't mean it..

I just wish there was another way for him to get the wrong stuff out.. with out having to flush it...

Aw screw it... flush it. Eagles right, your better off.

 

[redrockphil]

It'll be flushed later this week. Unfortunately I dont have another vehicle and cant afford to not drive it. Its been driving with the mix for about two weeks now, and have been luckyenough that nothing happened. I even went wheeling a couple of times through some tough stuff. Thanks all for the info. Its screwed up that there's a dealer that does that. I called them, all they said was, "We always use atf3 in all Jeeps we service. We'll flush out the old stuff and install mercon if you like, since thats what the manual says, but it wont make any difference."
Does anyone know the difference between the two?

 

[RINGKONG]

It'll be flushed later this week. Unfortunately I dont have another vehicle and cant afford to not drive it. Its been driving with the mix for about two weeks now, and have been luckyenough that nothing happened. I even went wheeling a couple of times through some tough stuff. Thanks all for the info. Its screwed up that there's a dealer that does that. I called them, all they said was, "We always use atf3 in all Jeeps we service. We'll flush out the old stuff and install mercon if you like, since thats what the manual says, but it wont make any difference."
Does anyone know the difference between the two?

You keep saying mercron... make sure they put in Dextron III

difference include.

Friction coeficients
Temprature tolerances
pressure differences
lube differences

in short.. your tranny was designed to run Dextron III and not ATF3..

 

[HossHoffer]

Use correct stuff

My family owned and operated an AAMCO transmission shop. The number one reason for trannys coming back for rework was the wrong fluid installed by the shop personell. The manager spent alot of time and training to alleviate this problem. Transmissions fluids vary according the the amount of pressure and lubrication needed in that particular application. In other words it lets the transmission shift when it needs to shift and lock up when it needs to lock up. Any slip is a bad thing. It is imperitive that you get the fluid in that your tranny was designed to use. I would be suspicious of a service manager that didn't know how important it is to use the correct fluid. Maybe he was just having a bad day. Ringkong pretty much enumerated the differences.

 

[redrockphil]

THANKS EVERYONE!!