When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
64 Starfire - What type of transmission fluid to use?
I changed the transmission filter in my 64 Starfire this weekend, and was wondering what type of fluid should be used to go back in? I tried to find your thoughts by looking through a lot of old posts but was not able to find anything, so I apologize if this is listed elsewhere. I learned of course that the Type A is no longer around. It seems that Dexron 3, or Dexron 6 is the default these days, but there is a lot of comment about not mixing types. Since I am not sure what was in the transmission when I changed it, what would be the best fluid to go with? Thanks!
If you weren't intending on keeping your vehicle original, I would have suggested converting it over to a THD-400.
The term "ATF" is quite broad. This is where I get my engine oil and this is what they have to offer as ATFs: https://www.oel-engel.de/navi.php?qs=ATF
Those comments about mixing oil types might have to do with modern types coming in contact with what you already have in there. In which case, I would have the Hydramatic flushed and then refilled with what's available.
If the fluid that's in there doesen't smell burnt, there's a possibility of re-using it, if you've put it aside.
What did you get for deposits and was there a magnet placed at the bottom of the pan? Changing filters and fluids are routinely maintenance measures which don't necessarily reflect on the severity of service between intervals
Last edited by Killian_Mörder; May 25th, 2020 at 08:56 AM.
In the following video, they explain why it's important to flush the entire transmission. The breadstick and waterpot is used to elementarilly explain the fluid's molecular breakdown, as well as what deposits to to the fluid. I don't know about those old Hydramatics. But, modern torque converters aren't manufactured with drain plugs. Therefore, old fluid will remain within, during routine fluid changes:
All the Dextrons are interchangeable and compatible so whatever you have or find will work the same in the Dextron line.
Just curious how does your Slim Jim shift now? Some shift good till they die others die before they shift. Mine was the latter..... Tedd
After I got it all back together and added fluid tonight I started it up and it made a terrible racket from the pan area at idle. Sounded like gravel or marbles being tossed around in there. Scared me at first so I shut it off and checked everything, visually. Not finding anything, I started it again. This time a little less noise, but still pretty bad. I thought maybe because it was still on the ramps the fluid was unlevel so I backed it off the ramps. Oddly, in Reverse the sound went away Also, in any forward gear there was no sound. The shifts seems good like they were before I started this process. But once back in Park or Neutral the noise returned. The more the car ran at idle the lesser the noise. So I am assuming it is air trapped in the system? I thought there was a case vent for this so not sure what happened. The noise is still there just less often now. I'm afraid to drive it really unless you guys have seen this before as 'normal' after a fluid change? I also replaced the filter, but didn't take anything else apart. Any ideas?
It didn't sound like the noise was coming from those areas, but hard to tell since i wasn't under the car. I thought perhaps the dipstick tube may be rubbing on the trans lines since you have to remove it to drain the fluid and when i put it back it may be angled a bit. I hope to do more investigation tomorrow when i have a helper. I'll let you know what i find.
All the Dextrons are interchangeable and compatible so whatever you have or find will work the same in the Dextron line.
1. There is no "t" in Dexron.
2. They're NOT "interchangeable". Dexron VI is supposedly backwards-compatible with Dex III, in GM vehicles. Other manufacturers (Including Allison) may or may not allow Dex VI in a vehicle spec'ed for Dex III. I have no info about Dex VI being compatible with a trans originally spec'ed for Type A Suffix A. Consider that Type A/A (when new) was about a hundred times thicker than Dex VI. (In use, it sheared and got thinner.) Transmission fluids have been getting thinner and thinner over the decades. https://en.wikipedia.org/wiki/DEXRON
That reminds me of an old joke making fun of F fluid being thicker in order to make up for less precision compared to GM's transmissions
The way it was explained to me, thousands of years ago:
Everyone used "paper"-in-resin friction material in the early automatics. They used Type A fluid which wasn't much more than motor oil.
Ford switched from "paper-in-resin" friction material to asbestos. Asbestos had a lower coefficient of friction (slippery) so they needed a "special" "sticky" fluid to make the clutches 'n' bands grab. Ford develops Type F (for Ford) fluid. It doesn't lubricate as well as GM fluid, it doesn't take as much heat as GM fluid, but they need it because they're using screwy clutch material.
Type F fluid makes GM clutches engage harder. Hot-rodders all over the world rejoice because this stuff makes a noticeable "difference". GM engineers grimace because the fluid is mis-matched to the clutch material, the hard shifts aren't really a benefit (if you have any power, a hard shift just blows traction) and the fluid is not as well-engineered as the GM stuff.
Eventually, Ford goes away from asbestos clutches, but can't be seen returning to GM specs because that would acknowledge Ford's failure. They develop their own version of Dexron (close enough to interchange, different enough that they can put their own trade name and spec sheet on it) and Mercon fluid is born. Now you know the origin of the Dex/Merc fluid still on the shelves long after those GM-Ford product specs have become obsolete.
For the record--I was still seeing Type A fluid on the shelves of a local auto parts store two years ago. They've gone out of business since then. I suspect Type A fluid is still available if you look hard enough.
Last edited by Schurkey; June 13th, 2020 at 02:27 PM.
...Hot-rodders all over the world rejoice because this stuff makes a noticeable "difference". GM engineers grimace because the fluid is mis-matched to the clutch material, the hard shifts aren't really a benefit (if you have any power, a hard shift just blows traction)...
Getting the tires to squeal upon shifting was probably impressive to them, when they had passengers in their rods
May 25th, 2020, 08:01 AM
