Mustang 4r70w atf recommendation

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So, my 2004 Mustang GT shifts fine, a little rough sometimes, but after braking, the trans takes a couple of seconds to re engage. The level looks fine, but I'm going to do a fluid and filter change just to start with, (cause who knows when the previous owner changed it) I'm wondering what brand you guys reccomend? I know it takes Mercon V, I'd like to use Amsoil, but it's going to run me 200+ and I'm not sure it's worth it. What do you guys reccomend?
 
Mercon V is the safe choice. There are substitutes out there but none have any measurable benefit and most cost considerably more.

SuperTech Mercon V is $4.82/quart at Walmart, if it isn't in stock they will ship it to the store for free. Dropping the pan on a 4R70W will drain 4.5 quarts, maybe 5. Any sealed bottle that says Mercon V and has a Ford license number is fine, the specification is strict. Buy the cheapest you can find.

Using AMSOIL as you suggest would not hurt anything but in that application it would certainly not have any benefit. Waste of money.
 
All my daily drivers for the past 18 yrs have required Mercon V. And Super Tech is the best choice imo.
 
Sounds like the solenoids could be dirty causing delayed engagement. If there is evidence of varnish I recommend a bottle of lubegard red or green in this case. I use it in every transmission I service and have never had a bad experience with it.
 
InB4 MaxLife.

Merc V of any brand is a safe choice and that's what I would use. Some approved fluids are semi-synthetic(Castrol IMV, Mobil multi-vehicle ATF and Kendall VersaTrans).
 
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Castrol Full Synthetic is an excellent choice. The popular Maxlife is also good stuff. You might also like Redline D4 or D6

Does your transmission have a drain plug? If not, get an aftermarket pan that has one. This will make future ATF changes much easier
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Maxlife is certainly good stuff and well liked. However, it's not the correct, higher viscosity requirement for the Mercon V job. (7.4 cSt vs. 5.8 cSt). Must have been a reason why Ford chose the higher viscosity.
 
I have used Supertech Merc V and Castrol Synthetic in the past, but use Maxlife now. Cheaper, readily available and works fine.

While I agree that Maxlife starts at a lower viscosity, it is supposed to be much more sheer stable vs reports of Merc V thinning out to lower than Maxlife ATF rather quickly.
I would rather a fluid that starts at 5.9 and stays at 5.9 than a fluid that starts at 7.4 and drops to 5.5.

And no, I have no proof other than what Valvoline had responded to me via e-mail a few years ago when I e-mailed them about Merc V recommendation being removed from the bottle (Merc LV was placed on the bottle, but Merc V has always been on the Maxlife ATF product info sheet)..
 
Originally Posted by 69GTX
Maxlife is certainly good stuff and well liked. However, it's not the correct, higher viscosity requirement for the Mercon V job. (7.4 cSt vs. 5.8 cSt). Must have been a reason why Ford chose the higher viscosity.


the lower-visc ATF didn't exist at the time
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Originally Posted by 69GTX
Maxlife is certainly good stuff and well liked. However, it's not the correct, higher viscosity requirement for the Mercon V job. (7.4 cSt vs. 5.8 cSt). Must have been a reason why Ford chose the higher viscosity.


No MERCON V was a basestock improvement over MERCON the viscosity for both products was the same. MERCON V was more shear stable.

Back to the OP I used Valvoline Maxlife with this transmission without issue and actually the transmission shifted a bit firmer but it stopped the harsh shift.
 
Would I see any benefit using a name brand fluid? Like motorcraft or mobil. Also, would you reccomend draining the torque converter as well and doing a whole fluid and filter change? I have a mercedes fluid vacume pump, would I be able to put that down the dipstick tube and pump the fluid out like I do for mercedes oil changes? I'm not sure where the dipstick enters.
 
I have the 4r70w in my F150. Drained the TC 1 time. It's a mess and high risk. If you cross thread those threads you are pulling the trans possibly. The vacuum change will only get you maybe 3 quarts. You can do that multiple times. I vacuum it out then drop the pan to minimize the mess. Filter always looks fine but more fluid comes out when you take it off and it's only like $12 online sometimes. No need to over think it. Many small changes is fine. More than most people will do.
 
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Originally Posted by Hansvoytek
Castrol imv is mercon V?

Approved by Ford against the Mercon V spec:

https://msdspds.castrol.com/bpglis/FusionPDS.nsf/Files/1C6B3533C4BF4B92802580B2005A9D57/$File/BPXE-AFE8UE.pdf
 
I've decided to buy a wix filter change kit. Comes with a new gasket and a filter, and I'll use some castrol imv, I can get a good deal on it. I'll also be using lubeguard green as somebody on here reccomended, seems like good stuff. Hopefully it will remedy my transmission. Eventually I'll pull it and do a partial rebuild. Maybe j mod it. Any other suggestions are welcome. This forum is awesome.
 
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