We purchased a relative's 2000 Regal with hail bumps but only 99k kilometers (62k miles). I noticed burnt smell on trans level check, so I changed fluid and filter and gasket. This says it holds 10 quarts and my change removed 7.5, so a complete flush seemed unnecessary. Now, 300 miles later, I have the same hesitation and judder and stinking oil already. Despite the hail damage, this is a solid car with low miles. Everything works and the engine/trans combo has a good track record. Do I have the one exception to the rule? Would Lube Guard Red or Lucas Trans restore some function? The MaxLife DexVI I installed seemed way too flimsy to absorb the pressures a modern auto trans goes through. It called for DexIII. What is the standard advice for this situation?
Buick Regal 3.8
- Thread starter RaymondA
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If the trans called for DexIII....I'd use good ol' Maxlife ATF in the big red jug.
I use it in my truck, which also calls for DexIII without any problems. I also add a bottle or two of LubeGard Red as well.
I think that's your problem....running DexVI in your tranny that wants the thicker DexIII
I use it in my truck, which also calls for DexIII without any problems. I also add a bottle or two of LubeGard Red as well.
I think that's your problem....running DexVI in your tranny that wants the thicker DexIII
ls1mike
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The 4T65E in that car will be fine with DEX VI, again I hope Trav chimes in, but I changed out the DEX III in 98 with no issues. Do not add any additives to this. The later 4T65E did have any changes to things to that the fluid would affect and they went to DEX IV. Hesitation and judder, do you have any codes? You should have them pulled. P1811 could cause this.
This tranny is very picky about fluid. Only DEX III or DEX IV.
This may help you.
https://bobistheoilguy.com/forums/ubbthreads.php/topics/3354924/1
This tranny is very picky about fluid. Only DEX III or DEX IV.
This may help you.
https://bobistheoilguy.com/forums/ubbthreads.php/topics/3354924/1
ive been changing the fluid in my 01 grand prix GT (same engine/trans as you) with Valvoline DEX/MERC for 5 years now. Just a simple drain and fill every year, (think i maybe did 2-3 drain and fills over a month long period the first time) and ive replaced the filter twice during all of that. To date, i have never had a single issue. I bought the car with 75000 miles and it now has 156000
what fluid did you use? ive read (over and over and over) on grand prix forums that using synthetic fluid (DEX VI i believe?) in my transmission can cause issues very similar to yours.. Ive never tested that though...
what fluid did you use? ive read (over and over and over) on grand prix forums that using synthetic fluid (DEX VI i believe?) in my transmission can cause issues very similar to yours.. Ive never tested that though...
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ls1mike
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Problem with that is some of them won't tell you they were having a problem before, or they have really high miles.
I have done it on all 4 of my 4T65Es with no issue.
I know Trav on here does the same thing. Both of my supercharged cars have/do run 13's on DEX IV.
I have done it on all 4 of my 4T65Es with no issue.
I know Trav on here does the same thing. Both of my supercharged cars have/do run 13's on DEX IV.
Originally Posted By: ls1mike
Problem with that is some of them won't tell you they were having a problem before, or they have really high miles.
I have done it on all 4 of my 4T65Es with no issue.
I know Trav on here does the same thing. Both of my supercharged cars have/do run 13's on DEX IV.
Yes i run Dex IV in all my GM transmissions, never an issue. The 4T65E works very well on the stuff, its definitely not too "thin".
As you know the dex IV is more viscosity stable than the old dex III so in a short time in service it is actually "thicker" than the dex II would be.
It sounds like the OP's unit has some serious problems but more info is needed to get any sort of accurate idea.
Transmission codes? A scanner will provide the info such as the tranny temp, shift times and shift errors, TQ lockup, etc this would be good information.
It could be a few things, low pressure, a kinked or damaged line going to/from the radiator, bad seals, TQ lockup issue or a host of other things.
At this point we are sort of dancing in the dark, we don't even know what the fluid temp is or what if any codes it has only that its smells burnt.
Problem with that is some of them won't tell you they were having a problem before, or they have really high miles.
I have done it on all 4 of my 4T65Es with no issue.
I know Trav on here does the same thing. Both of my supercharged cars have/do run 13's on DEX IV.
Yes i run Dex IV in all my GM transmissions, never an issue. The 4T65E works very well on the stuff, its definitely not too "thin".
As you know the dex IV is more viscosity stable than the old dex III so in a short time in service it is actually "thicker" than the dex II would be.
It sounds like the OP's unit has some serious problems but more info is needed to get any sort of accurate idea.
Transmission codes? A scanner will provide the info such as the tranny temp, shift times and shift errors, TQ lockup, etc this would be good information.
It could be a few things, low pressure, a kinked or damaged line going to/from the radiator, bad seals, TQ lockup issue or a host of other things.
At this point we are sort of dancing in the dark, we don't even know what the fluid temp is or what if any codes it has only that its smells burnt.
I wouldn't recommend any additives at all. I have very low regard for most fluid additives, but there's a special place in the netherworld for transmission snake oils.
It should be just fine on DexVI. In many ways, DexVI is the best transmission fluid ever put on the market, and GM considers it backward-compatible for most applications.
It should be just fine on DexVI. In many ways, DexVI is the best transmission fluid ever put on the market, and GM considers it backward-compatible for most applications.
ls1mike
$50 Site Donor 2025
DEX-VI...Typo. Sorry for the confusion.
Check out the photos in my link.
Your 1990 has a 700R4, much different than a 4T65E
Check out the photos in my link.
Your 1990 has a 700R4, much different than a 4T65E
Originally Posted By: Phishin
Listen, you guys (Trav and ls1mike) are talking about using DEX IV in your 4T65E trannnies.
The OP said he put in DEX VI. Not DEX IV. Have either of you two (Trav or ls2mike) ever ran your cars with DEX VI?
Typo. I blame Mike.
We know it should be VI.
Listen, you guys (Trav and ls1mike) are talking about using DEX IV in your 4T65E trannnies.
The OP said he put in DEX VI. Not DEX IV. Have either of you two (Trav or ls2mike) ever ran your cars with DEX VI?
Typo. I blame Mike.
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ls1mike
$50 Site Donor 2025
Originally Posted By: Trav
Originally Posted By: Phishin
Listen, you guys (Trav and ls1mike) are talking about using DEX IV in your 4T65E trannnies.
The OP said he put in DEX VI. Not DEX IV. Have either of you two (Trav or ls2mike) ever ran your cars with DEX VI?
Typo. I blame Mike.
We know it should be VI.
I know what a goof I am sometimes...I will take it...Man I was tired when I typed that. I do not like roman numerals!
Originally Posted By: Phishin
Listen, you guys (Trav and ls1mike) are talking about using DEX IV in your 4T65E trannnies.
The OP said he put in DEX VI. Not DEX IV. Have either of you two (Trav or ls2mike) ever ran your cars with DEX VI?
Typo. I blame Mike.
I know what a goof I am sometimes...I will take it...Man I was tired when I typed that. I do not like roman numerals!
MolaKule
Staff member
Quote:
Now, 300 miles later, I have the same hesitation and judder and stinking oil already.
The oil still stinks because you haven't replaced all the stinky fluid.
Try another drain and fill for about two more times.
It may take awhile before all the crud has been dumped, especially if this tranny has not had periodical maintenance.
And also try and get a code reader as Trav said and see if there are any historical tranny codes lurking.
Now, 300 miles later, I have the same hesitation and judder and stinking oil already.
The oil still stinks because you haven't replaced all the stinky fluid.
Try another drain and fill for about two more times.
It may take awhile before all the crud has been dumped, especially if this tranny has not had periodical maintenance.
And also try and get a code reader as Trav said and see if there are any historical tranny codes lurking.
Thank you all for taking the time to educate a first timer like me. I am going to assume this car has had a few winter reverse to drive snow incidents and hope my gentle driving and superior care will allow me to get 20k miles out of it. I think you're right that the smell is due to not draining the TC and getting ALL the old fluid out. I am going to do it again today after a Seattle round trip and hope Dex III and Lube Guard Red will make it a little more stable. I cannot get the viscosity of the DexVI out of my brain - it is almost water-like. To an old timer like me it is hard to understand. I will get the codes read today when I pick up the fluid and post the results. Again, thanks to all for your input. Never is there too much knowledge, especially when it comes to our cars.
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