I'm in the process of rebuilding my 67' GTO 400 motor. I pulled the transmission which is a GM TurboHydramatic 400, It is a PX series, 2 dimple pan, which was used on late 67' GTO's. Having the tranny gone through by a good transmission shop to do a little "beefing up". My question is: what is the best Mercon 3 ATF fluid to use in this older transmission? I normally use Mobil 1 Synthetic ATF in my newer vehicles but not sure this is the best approach for this older 400 tranny. This auto is a "cruiser" with a 350hp motor and not used a racer. Should I use regular ATF (what brand) or go with a true synthetic?
What ATF fluid for an Older Turbo 400?
- Thread starter pharmer
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well first of all, there is no such critter as Mercon-3. There is plain Mercon, Mercon-V, and Mercon-SP. I'm sure you meant Dexron-3 which is typically also rated Mercon, which is why the lables on such ATF bottles say Mercon/Dexron-3 or Dexron-3/Mercon.
I would like to see more people try this Meron/Dexron-3 fluid... http://www.specialtyformulations.com/AUTOGlide.htm
Hammer
I would like to see more people try this Meron/Dexron-3 fluid... http://www.specialtyformulations.com/AUTOGlide.htm
Hammer
My choice in Dex-Merc ATF is SCHAEFFER's #204-Supreme (ordered from site sponsor). A blend, and has been excellent in hard daily town use in an AISIN-WARNER auto trans. Changed after a year and fluid looked/smelled as new, even with North Texas heat and extensive idling. (Vehicle also had auxiliary trans cooler and MAGNEFINE auxiliary filter).
I used M1 ATF in another Jeep with AW-4 the son just bought because of being pressed for time. I'd have rather had the #204-S.
I used M1 ATF in another Jeep with AW-4 the son just bought because of being pressed for time. I'd have rather had the #204-S.
Hammer, Your're absoulutely right! I knew it was Dextron 3 I was inquiring about but my old senile fingers typed the word Mercon. My bad. I tried the site you sent but it kept coming up "page cannot be shown". Do you have a particular brand ATF that you recommend? Thanx.
The ATF's already mentioned are all very good, or you could use the Mobil 1 Dex III/ Mercon that you are using in your newer cars and stock only one kind of fluid.
A built 400 will work well with ANY ATF if kept at a reasonable temp. If your cooler is big enough, use any Dexron III.
Change the ATF at a reasonable interval(get a drainplug installed or a deep pan with drainplug) to prevent varnishing of the VB and mechanicals.
Check with the rebuilder to see if the clutches that will be used are picky. Some brands might not tolerate certain types of fluids.
I'd used the Mobil1/Torco/RoyalPurple or other high quality synthetic or blended ATFs.
Change the ATF at a reasonable interval(get a drainplug installed or a deep pan with drainplug) to prevent varnishing of the VB and mechanicals.
Check with the rebuilder to see if the clutches that will be used are picky. Some brands might not tolerate certain types of fluids.
I'd used the Mobil1/Torco/RoyalPurple or other high quality synthetic or blended ATFs.
This link just worked for me: http://www.specialtyformulations.com/products.htm
The product is called Autoglide. The member named "Molakule" owns SF and he can answer any questions you have about this product.
Hammer
When I had the powerglide in my 1964 Impala rebuilt in 1988, I had them use Amsoil ATF.
It was in there for 14 yrs when I sold the car in 2002. It worked just fine.
It was in there for 14 yrs when I sold the car in 2002. It worked just fine.
Install a universal drain plug. I used a MotorMite unit from NAPA on my '95 K1500 4L60E w/ 164k+ miles for easier drain/refills.
Wal-Mart Super Tech is actually spec'd to GM's DEXIII specs (not just "meets the spec"). I used it and added 1 1/2 bottle of LubeGuard and it shifts just fine, even at the beach with 4x4 action.
It's cheap and you can drain/refill once a year with out it draining your wallet.
If you have $$$, go with AMSOIL.
Wal-Mart Super Tech is actually spec'd to GM's DEXIII specs (not just "meets the spec"). I used it and added 1 1/2 bottle of LubeGuard and it shifts just fine, even at the beach with 4x4 action.
It's cheap and you can drain/refill once a year with out it draining your wallet.
If you have $$$, go with AMSOIL.
Local trans rebuilder in town with a 5 year 60k warranty uses Amsoil ATF in every one of their rebuilds.
As mentioned above I believe they can use just about any fluid.
I just had my Turbo 350 on my 71' Olds rebuilt last year and my mechanic put in the Chrysler ATF +3. He said it has a better additive package than the Dextron and will last longer...FWIW!
The car shifts and drives fine...
I just had my Turbo 350 on my 71' Olds rebuilt last year and my mechanic put in the Chrysler ATF +3. He said it has a better additive package than the Dextron and will last longer...FWIW!
The car shifts and drives fine...
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