No they aren't but, put Dexron in a Ford transmission that requires type F and see what happens.
Don't keep us in suspense.
They become a slush box. It's been my experience after 45 years in this business that in some cases choosing the wrong fluid for your transmission can indeed destroy it. Many fluids don't mix well and quite frankly since the OP is discussing a stock transmission where all the fluid can not be removed the only safe answer here is to replace the fluid with approved fluid. Now if you are building a high performance transmission with all new frictions and a converter where all the fluid is going to be replaced then starting out with type F is OK, but just replacing half the fluid with type F isn't the best advice in my opinion.
Here is some reading and a Ford transmission fluid history lesson.
From a stock view point you are correct, GJ. Dexron has friction modifiers to allow smoother shifting. Type F does not. Naturally, if you put Dexron in a Ford or any other AT calling for Type F you will trash it in short order. If you have a restored ride where you aren't looking for maximum performance then Dexron is fine. Type F has been run for years and years in Mopar and GM performance builds to enhance shifts, at least in old school transmissions (727, 904, PG, TH350-400, etc.). I honestly have no idea on newer trans models. As far as mixing fluids, I should clarify I WOULD put Type F in a GM or Mopar trans if it was all I had on hand but WOULD NOT consider Dexron in a Ford. Basically, it's what your looking for in your end result.
Tim
'71 Charger 383/727 '17 Challenger SXT (Wifeys car )
Hi, this is the OP of this thread again. I'm still a little in the dark as to what ATF to use in my 69 727 trans. What do you guys think about using Dexron/Mercon. Is that good stuff? And should I drain the entire trans system first, because I have no idea what the previous owner put in it for ATF. Thanks once again.
You got your monies worth after using your fluid for 20 years.
Drop the pan. If you have a converter drain plug remove it to drain the converter. If no converter drain plug - loosen up the valve body and that will drain half the converter.
Remove both cooler lines at the trans case, blow air in to the return cooler line ( the one that attaches to the back of the main case ) with the front line placed in to a drain pan, bucket or whatever. This will remove the fluid in the lines. Inspect for debris in this fluid.
That will get out as much fluid as you can from the system.
New filter, adjust the bands if you wish.
Add ATF+4, any Dexron fluid you wish, or the preferred Type F ( used for years without issue on race cars and street cars ).
After adding about 4 quarts, with more on hand, start it in neutral and add slowly until warmed up, run it through Reverse, manual low then top it off while in neutral.
People on here had been sayin for a long time that type F is OK & Walmart has it so I went there yesterday & got some. Transman thank you for the info on the draining
live every 24 hour block of time like it's your last day on earth
No they aren't but, put Dexron in a Ford transmission that requires type F and see what happens.
Don't keep us in suspense.
They become a slush box. It's been my experience after 45 years in this business that in some cases choosing the wrong fluid for your transmission can indeed destroy it. Many fluids don't mix well and quite frankly since the OP is discussing a stock transmission where all the fluid can not be removed the only safe answer here is to replace the fluid with approved fluid. Now if you are building a high performance transmission with all new frictions and a converter where all the fluid is going to be replaced then starting out with type F is OK, but just replacing half the fluid with type F isn't the best advice in my opinion.
So, tell us, in technical terms how a Ford transmission differs from a GM or Mopar. Is the friction material compounded differently? Are the bearings and bushings way different?
I totally agree on the difference in lubricity and coefficient of friction differences and that type F is a bandaid to patch a flawed design but in many cases the more aggressive friction characteristics are desirable and the slight difference in lubricity isn't really a factor. Manufacturer's specs for fluid, in most cases is simply a matter of "made here"...IOW, if it isn't made here it spells disaster, kinda like your Mopar dealer chanting "use only genuine Mopar parts in your new Dodge".
In newer transmissions with overdrive and lockup converters, fluid choice is a lot more critical than in the old transmissions most often discussed here. Look at how many here have had success with John Deere tractor fluid and AW-32 hydraulic fluid. Are their anecdotal stories of success any more/less credible than your anecdotal story of failures associated with the wrong fluid and, most likely, lacking laboratory failure analysis?
Valvoline Dex/Merc is not synthetic. Type F supposedly will give firmer shifts so if that's what you want in lieu of better protection I guess.
I don't understand why this is a recurring controversy, but then I'm no expert.
I use this stuff (dex/merc) in both my 727's. is it the best stuff on the planet? don't know, but the factory and rick Allison at A&A who built both trans told me to use it. haven't had any issues but I don't abuse them either. it's probably like anything else; keep it clean and do proper maintenance.
Nothing wrong w/ the B&M Trick-shift fluid...it's just that you're paying too much for regular old Type F that's been dyed blue.
Just picked up a case of the cheapest Type F they had at O'reilly auto parts today for the 727 my 1150 hp street driven hemicuda. Same stuff I've been running it for years w/ no issues.
No they aren't but, put Dexron in a Ford transmission that requires type F and see what happens.
Don't keep us in suspense.
They become a slush box. It's been my experience after 45 years in this business that in some cases choosing the wrong fluid for your transmission can indeed destroy it. Many fluids don't mix well and quite frankly since the OP is discussing a stock transmission where all the fluid can not be removed the only safe answer here is to replace the fluid with approved fluid. Now if you are building a high performance transmission with all new frictions and a converter where all the fluid is going to be replaced then starting out with type F is OK, but just replacing half the fluid with type F isn't the best advice in my opinion.
So, tell us, in technical terms how a Ford transmission differs from a GM or Mopar. Is the friction material compounded differently? Are the bearings and bushings way different?
I totally agree on the difference in lubricity and coefficient of friction differences and that type F is a bandaid to patch a flawed design but in many cases the more aggressive friction characteristics are desirable and the slight difference in lubricity isn't really a factor. Manufacturer's specs for fluid, in most cases is simply a matter of "made here"...IOW, if it isn't made here it spells disaster, kinda like your Mopar dealer chanting "use only genuine Mopar parts in your new Dodge".
In newer transmissions with overdrive and lockup converters, fluid choice is a lot more critical than in the old transmissions most often discussed here. Look at how many here have had success with John Deere tractor fluid and AW-32 hydraulic fluid. Are their anecdotal stories of success any more/less credible than your anecdotal story of failures associated with the wrong fluid and, most likely, lacking laboratory failure analysis?
You are totally missing my point. I said starting fresh with type F would be OK didn't I? But the OP is not starting from fresh. He's had the car for 20 years and never changed the fluid. Who really knows how long it has been in there? I personally would not be looking to change the frictional characteristics in this transmission at this point. It's even possible that just putting in fresh Dexron might not be a good idea but it's better than type F in this instance.
"Follow me the wise man said, but he walked behind"
'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion. '74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost coming soon! 2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.
Thanks guys for all the advice and your opinions. I value all of them. What I've decided the best thing to do is, drain out all or as much of the old ATF as possible from everything and replace it with Dexron/Mercon ATF. At least then I'll know for sure what type ATF is in the tranny. I'll empty the pan, drain the converter, blow out the bottom tank on the radiator with some air, and replace the trans filter. Sounds like a lot of work just to replace a leaking pan gasket, but I don't want to take a chance on mixing different fluids together, and screwing up my transmission. Again thanks for everyone's help.
Re: Tranny fluid dilemma.
[Re: BloFish]
#2651102 05/02/1901:32 AM05/02/1901:32 AM
That's all I use. Since I worked at Dodge dealer for 24 years and did trans work I have a small stock of ATF+4 and its all I use in all my Mopars as does my brother. Is it the best ?? Depends on who you talk to most of the time but it works great for me. I have it in my 63's trans and my sons Dart and both are still working like new. The Dart has been on the road since 1997 and my 63 since 2006. Course back in the 90's it may have been ATF+3 that was in the Dart at first. But they still shift nice and firm and fluid is a good color and we have never had a trans failure in any of the cars. So I use it in all my Mopars. Ron
Re: Tranny fluid dilemma.
[Re: 383man]
#2651168 05/02/1910:45 AM05/02/1910:45 AM
lets add this question to add to the confusion. what happens when you change to "xxx" fluid from amsoil "super shift", which is a synthetic ? instant failure ?
Only time I ever put type F in a 727 was years ago. I had a push button 727 in my 64 300. Decided to do a band adjustment and fluid and filter change. Reading the DC books lead me to think putting in type F might be an improvement. Drained out the whatever was in it, did my band adjustments put in a new filter, filled it up with type F. Two days later it's slipping and all the friction material came off the clutches.
Coincidence?
I don't think so and the cost of even a DIY rebuild is more than I care to spend to retest the type F experiment.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
Only time I ever put type F in a 727 was years ago. I had a push button 727 in my 64 300. Decided to do a band adjustment and fluid and filter change. Reading the DC books lead me to think putting in type F might be an improvement. Drained out the whatever was in it, did my band adjustments put in a new filter, filled it up with type F. Two days later it's slipping and all the friction material came off the clutches.
Coincidence?
I don't think so and the cost of even a DIY rebuild is more than I care to spend to retest the type F experiment.
Wasn't the fault of the fluid.Type F has been a mainstay in the older Mopars since the 60s.
)
Thanks once again.
