Trans fluid .

I got to the plug easy but never got it out.
Had the converter on the bench and the plug broke off. I bought a new converter.
Your experience is not typical. Someone overtightened or cross threaded the plug. I sometimes think most of the work I do on my old cars is fixing something somebody f'ed up in the past.

That said, I've never had a problem, never heard of that problem.
 
I pump six quarts of this out the dip stick tube every 20k mile on my Dakota. That little truck has been properly abused towing 5 to 10k pounds all over the southeast since 1993. It has 250k miles on it.
Napa has it for $25 a gallon this month, no shipping charge. If it's ordered online for home delivery it must be purchased three gallons at a time. No more no less. Probably for packaging purposes.

Napa just canceled my last order made on 11/24/24. Must be all gone. Bummer.
 
I always thought Dexron III was standard refill. Seems to work good in a couple 727's I have.
In one I put in a small bottle of Lucas trans fix and it took care of some slippage I had going in reverse.
 
The last time I flushed a transmission, just because it had a ton of miles, I lost reverse, slipping bad. Had no problems before the flush. Afterwards I asked around and heard the same thing from more than one source: You should not flush the fluid, reason because all the by products of all those miles are helping to create friction needed. The fresh clean fluid doesn't perform well in a "worn" transmission. The result is slipping / slippage. I like to keep fluids clean and fresh in my vehicles and machinery. I don't know if there's any merit to the theory or not but I'v never had a auto. trans slip until I changed the fluid. It wasn't a 727 either it was a 2018 chevy v6 trans. I read thru the thread wondering if there would be any mention of that theory, which is what I'm calling it. I don't know jack about transmissions, I know a little about hydraulics and I know enough to run correct, clean oil via quality filter, etc. Has anyone ever heard of the theory "don't change the fluid" aka "clean fluid=slippage w/ high miles"
 
I have not heard of any torqueflites doing this but a Th 350 and a Th 400 doing that after fluid change.
 
The last time I flushed a transmission, just because it had a ton of miles, I lost reverse, slipping bad. Had no problems before the flush. Afterwards I asked around and heard the same thing from more than one source: You should not flush the fluid, reason because all the by products of all those miles are helping to create friction needed. The fresh clean fluid doesn't perform well in a "worn" transmission. The result is slipping / slippage. I like to keep fluids clean and fresh in my vehicles and machinery. I don't know if there's any merit to the theory or not but I'v never had a auto. trans slip until I changed the fluid. It wasn't a 727 either it was a 2018 chevy v6 trans. I read thru the thread wondering if there would be any mention of that theory, which is what I'm calling it. I don't know jack about transmissions, I know a little about hydraulics and I know enough to run correct, clean oil via quality filter, etc. Has anyone ever heard of the theory "don't change the fluid" aka "clean fluid=slippage w/ high miles"

My 1966 727 was running on naught but dirty fluid, Type F fluid and Lucas for the first couple years I ran it. When I finally had it rebuilt, the old guy who did it showed me the clutches. THERE WAS NO PADDING LEFT!! We surmised that the only thing which enabled the things to grip was all the crap in the fluid. They cleaned it all up, installed new clutches, replaced a band, used the modest shift kit I found, advised me that the pump chamber is worn to the point that this should be the LAST rebuild, and filled it w Castrol Transmax. That was 6 yrs ago, and it behaves nicely enough. I have a 1968 727, and a 1977 one, so I don't worry. I know the '68 worked fine when we got Gertrude in 2021.
 
You should not flush the fluid, reason because all the by products of all those miles are helping to create friction needed
That may be true, but I've seen it more as "a flush just reveals any problems that may have been previously unknown" - if problems appear right after a flush, it was more than likely that the gearbox was already on its way out and the old fluid was just the duct tape holding everything together.
It's like that whole "synthetic oil causes leaks" meme, it doesn't cause leaks, it merely reveals them.
 
GM no longer regulates DEX III but you can get similar with an Allison spec
it' the wild west with DEX III so only get brand name stuff
that said DEX III is way obsolete
+4 is semi synthetic and a much better base fluid
That said
CITGO Quatrosyn is the best fluid you can get
no modifiers so it CANNOT shear down and best of any hot and cold performance and longest life
 
One more question, going to change filter and fluid in my 68 300. Original, stock 727 transmission. Whats recommended fluid to put back in? Only a few options now days. Thanks for the help.
I just saw this today, i put Mobil1 synthetic in a 727 10 years ago.. new filter, band adjustment… never had a hiccup..
 
GM no longer regulates DEX III but you can get similar with an Allison spec
it' the wild west with DEX III so only get brand name stuff
that said DEX III is way obsolete
+4 is semi synthetic and a much better base fluid
That said
CITGO Quatrosyn is the best fluid you can get
no modifiers so it CANNOT shear down and best of any hot and cold performance and longest life
I did use Valvoline...

One of my cars the tranny was rebuilt before I bought it and it seemed to shift firmer than expected and assumed maybe there was Type F. Definitely shifts softened now with Dex III but never heard of the Citgo..

The other trans is original 120K so I will just stick with the obsolete stuff in that one...
 
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I have to chime in on fluid... Manyyears ago I was the product line manager at Mopar Parts Div. for fluids and chemicals. This was when the ATF+ fluids were first introduced; the synthetic was needed to manage shudder in the newer lockup transmissions. I quizzed the engineers on backwards compatibility and they told me that the new fluids would work all the way back to the old Type A fluids. They were concerned with dealers missapplying fluids and causing failures so compatibility was engineered in.
Also, Ron Mancini ("Zoomo", Chrysler engineer and Ramchargers member) (RIP Ron) told me to use Type F for firmer shifts in older 727 and A 466 trans. His racing specialty was transmissions so he knew his stuff. He also preached religously draining and flushing the converter and COOLER if you are doing a rebuild of a failed (metal shavings) transmission. You can buy spray flush kits for the cooler.
Hope this helps.
Mark
 
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