Engine/Transmission (1998.5 - 2002) Switched to dextron III

[SKargo]

Did a trans service last week, and swapped from atf4 to the dIII. At first, I had a problem with the tc locking and unlocking, but a tech at work reflashed my trans and it works perfectly now. Not sure why it even started unlocking and locking all of a sudden though.

 

[SnoKing]

And why did you put Dextron III in it????? SNOKING

 

[SKargo]

And why did you put Dextron III in it????? SNOKING

For something to do. I've read about people here doing it, and wanted to see if it took away my very occasional shudder, it did.

 

[bmoeller]

The D3 CAUSED the shudder in the old stock transmission. May need to add friction modifier to the oil.

 

[SKargo]

OK,

maybe this was a bad move. I towed my new(to me) desoto home tonight, and rolling into it at about 70 mph going up an intermediate incline, I got the TC to shudder. I could keep it under control easily with the skinny pedal.



I will flush it out and out the atf4 in it tomorrow. With that, it only shuddered twice, and under extreme conditions.



Otherwise, it's shifting better, and running cooler than before.

 

[Hahn007]

OK,

maybe this was a bad move. I towed my new(to me) desoto home tonight, and rolling into it at about 70 mph going up an intermediate incline, I got the TC to shudder. I could keep it under control easily with the skinny pedal.



I will flush it out and out the atf4 in it tomorrow. With that, it only shuddered twice, and under extreme conditions.



Otherwise, it's shifting better, and running cooler than before.

Sounds like your TC may be headed south. Soon after adding the EZ to my truck my TC started to shudder as well. Withing a short time it would slip while locked and in OD. If left in this condition you will heat up and scorch the trans fluid and eventually ruin the rest of the trans.



Chris

 

[keimmmo]

I read on here somewhere a few years ago that when you convert to Dexron III you should add 1 quart of SYNTHETIC 5W-30 motor oil to the ATF. I have been doing so for over 100k without a problem... of course, I have no power mods.



I put a drain plug in my trans pan. I just pull the plug and change the fluid every 15k-20k miles. I drop the pan and change the filter every 3-4 fluid changes.



Steve

 

[SKargo]

I added some lucasoil trans treatment and everything seems fine now.

 

[Nate]

Why don't you just use ATF +3/4 like your supposed to? Putting Dextron/Mecron in a Dodge transmission will kill it in short order.

 

[SKargo]

Why don't you just use ATF +3/4 like your supposed to? Putting Dextron/Mecron in a Dodge transmission will kill it in short order.

No it won't.

 

[keimmmo]

I repeat, 100k trouble free. That doesn't seem like a quick death to me. Besides, just TRY to find ATF+4 in Central Mexico! I haven't found it at ANY price!!! There is something to be said for using what you can get.



Steve

 

[SKargo]

I repeat, 100k trouble free. That doesn't seem like a quick death to me. Besides, just TRY to find ATF+4 in Central Mexico! I haven't found it at ANY price!!! There is something to be said for using what you can get.



Steve

Actually, you're post prompted me to put the lucasoil in. I know it's not exactly what you do, but same principal.

 

[Lsfarm]

ATF 3/4 vs Dexron III/Mercon

ATF in any transmission has two main jobs, lubrication of the gear train, bearings and seals, and to act as a hydralic fluid to transfer hydralic pressure to the various clutches and band-apply servos.



In some transmissions a shudder will occur when a clutch is applied. This is the result of low pressure applied slowly. The clutch grabs, then releases several times per second. Chrysler decided that the cause was that Dexron ATF was too 'grabby' [not the VB valving and engagement rates] and added friction modifiers to the fluid to make it MORE SLIPPERY. This became the third job for ATF in stock transmissions: to slip more to reduce shudder, at the expense of fiction material [clutches and bands] longevity.



The result is that when a clutch is engaged it will slip untill enough pressure is applied to hold it in place. So if it is slipping and not shuddering, can you tell if it is slipping?? NO!!



For me I'd rather know if a clutch is slipping and shuddering and control it with the gear selection or throttle pedal or both. Otherwise the first indication of a slipping clutch will be high temperatures and burnt ATF and a trashed transmisssion.



The early non lockup TC transmissions were Dexron transmissions. Only with the addition of the lockup TC did the ATF+3 and +4 come into exsistance. The +3/+4 is much more expensive and doesn't do anything good for the trans, only costs more. It makes Minivan , LHS, Intrepid and Stratus transmissions shift smmoootthh. [gag]



If a stock transmission is shuddering, either select a lower gear, or floor it so that the TV cable will pull on the TV arm and depress the throttle valve and push up the trans pressures. . with the result that the clutch will grab and engage and stay engaged. [unless your trans is worn out or you have too much power for the trans to hold]



When you sloowwllyy roll into the throttle with a fuel box with small amounts of throttle pedal travel, you have high torque and low trans pressures, the result is a slipping transmission.



Why use Dexron @ $. 95/qt instead of +3 @ $2. 50/qt or +4 @ $4. 50/qt ?? Because you can change the trans ATF three times as often and help your transmission to last longer by doing so. Clean ATF lubricates better and runs cooler.



All my transmissions get Dexron III/Mercon and a recommendation to change every 10K.



Just my experiences and opinions Greg L

 

[Nate]

Well that's good info, quite a bit different from what I was told.

 

[keimmmo]

Greg,



I don't know if it was you or someone else, but in reading information on here a couple of years ago from transmission builders, I decided to use the DexIII and synthetic motor oil. I have a trans temp gauge. I have never seen high fluid temps. I change the fluid every 15k-20k miles and it looks and smells like new when I drain it. I have never felt the transmission shudder or slip. And, I can get it here in Mexico... even most dealers do not carry the ATF+4 down here!



Steve