Switched from Dexron III to VI

#1
I did a tranny fluid/filter change and added a Hughes deep pan while I was at it.
Always had used Dex 3 but used Dex 6. I was really surprised by the change in driving experience.

My car has a CK shift kit and frankly the 1/2 was a bit of a neck jerker, but it is much softer now.
The 1/2 part throttle chirp is gone but otherwise it runs very nice. It will roast the tires on the shift if your foot is in it.
The shift points are the same and the 2/3 is crisp. The car has 52K.

It almost feels a bit looser. It may take me a bit to get used to not having that 1/2 slam on the shift. Was thinking of maybe adding
a quart of trick shift or F for better grip on the shift.
 

SS/GN

Well-Known Member
#2
The 6 is backwards compatible and a great fluid. I changed both my cars a few years ago and honestly did not notice any difference. You might want to check the cable adjustment.
 

Charlie Gaudet

Resident Jet Mechanic
#3
If you didn’t touch the cable during fluid change then check the fluid level. Also, did you remove the orange o ring that gets stuck in the transmission when Changing the filter? If the filter isn’t seated all the way in and loose you will be sucking in air and can cavitate the pump. Just my $.02.
 
#4
The 6 is backwards compatible and a great fluid. I changed both my cars a few years ago and honestly did not notice any difference. You might want to check the cable adjustment.
Do you have shift kits in either cars ? It for sure softened the 1/2 at part throttle in mine which is actually nice

If you didn’t touch the cable during fluid change then check the fluid level. Also, did you remove the orange o ring that gets stuck in the transmission when Changing the filter? If the filter isn’t seated all the way in and loose you will be sucking in air and can cavitate the pump. Just my $.02.
LOL. The O-ring is always the worst part about the filter change!!! Tricky to get out sometimes. Cable, filter, fluid level is good.
The tranny definately performs delivers when called on.

I think since the fluid is so thin it changes things a little, I read it is 40% thinner than III, I used AC Delco brand.
I feel like the converter is a little looser and the car coasting on the highway is smoother/less resistance, could be nuts though.

After driving a bit more I'm really good with it. Wont be adding any trick shift or F.
 

SS/GN

Well-Known Member
#5
I have a CK kit in one and an older kit in the other. I never really noticed anything on the change. If you have checked everything over then you are probably good to go. I would never mix other fluids or additives. I think an oil is like a recipe and too many hands in the brew wreck the sauce;)
 
#8
I just installed a Hughes deep pan on my tranny and I switched from Dex 3 to Dex 6 and noticed the same thing with my tranny not having that hard jerk to it. The tranny now feels a little soft, but I'm sure that I will get use to it.
 
#9
Serviced my trans last weekend. New TCC solenoid and filter etc. I used DEX VI and all seems well. Haven't driven it much since. It was still barking 1/2 shift pretty good. My TCC was bad and the new one fixed it. Feels good to have it fixed and I did it myself.
 

IrvJr

Well-Known Member
#12
I was kidding. My builder suggested VI and i havent had any issues and have noticed a bit smoother shifts and reduced harshness.
 

468Chevelle

Not the Jiffy lube symbol
#13
I had the same thing when switching. Softer 1-2. Drove like that for 6k miles. Added a bottle of Lucas, trans went back to the hard shifts.
 

IrvJr

Well-Known Member
#14
I dont mind the softer 1-2 at part throttle, maybe i miss the chirping tires. LOL but with more throttle they are still quick and firm.