4R100 fluid

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the 4R100 in my F250 has been leaking, well not leaking but a few drops on the pan, since I got it from my cousin back in November. Crawled underneath yesterday with my torque wrench to see if any were loose, most of them were loose, I tried tightening them to 125 inch pounds and I could only get a few turns on one bolt before the gasket( cork gasket and looks to be the original) cracked and started pushing out from the side of the pan(way before the wrench clicked, and 125 inch lbs isnt much). I'll pick up one of the updated reusable Motorcraft gaskets from the dealer Thursday, and change the gasket and filter along with a drain and fill of the fluid. Hopefully it can last until I have time to pull it out and build it. I'm not hard on the truck, most shifts are at 2k rpm and the other day I floored it to 3k, I dont do it often, for being an old tranny with the miles on it it still shifts well. my question is, I've heard I can run Dexron III/Mercon in it, and also Mercon V. Some say not to use Mercon V in the 4R100, while others say Ford changed the formulation and its now compatible with the 4R100. I was thinking of going with Supertech for the Dex III/ Mercon or Supertech Mercon V, would that be a good choice or should I get a different brand? Are Supertech trans fluids good? Should I use Dex III or Mercon V? Thanks
 
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Yes, Mercon V is now compatible with regular Mercon. I think the change was around 2005.

Nothing wrong with Walmart brand ATF, and the ST Mercon V should serve your needs with no problems.
 
I used Valvoline Mercon V. It is backwards compatible with our transmission. It wouldn't hurt to browse the forums dedicated to our trucks just to be safe.
 
Originally Posted By: slacktide_bitog
Yes, Mercon V is now compatible with regular Mercon. I think the change was around 2005.

Nothing wrong with Walmart brand ATF, and the ST Mercon V should serve your needs with no problems.


If the two are mixed, will that cause any issues? Reason I ask is because the last service on my 01 F250 was done at a shop and I don't know if he used Mercon or Mercon V. I'm planning on dropping the the pan to replace the gasket and filter. I plan on using Maxlife.
 
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Originally Posted By: Mantooth
If the two are mixed, will that cause any issues? Reason I ask is because the last service on my 01 F250 was done at a shop and I don't know if he used Mercon or Mercon V. I'm planning on dropping the the pan to replace the gasket and filter. I plan on using Maxlife.


here will be no problems doing this, and Maxlife is great stuff
smile.gif


Does your transmission have a drain plug? If not. consider the Dorman pan that has one, which will make future ATF changes easier.
 
I spoke to John Wood today, hes one of the most renowned 4R100 transmission builders in the country. He told me to drain the pan, change the filter and to also drain the torque converter (99 year models have a converter drain plug). He said to fill it up with 10 quarts of Maxlife syn trans fluid, then start the truck and as soon as its started to pour in 5 more quarts, shift through the gears and then check the level from there. While I will do that and 100% trust what he told me, should I go ahead and do a flush with the tranny cooler lines like I see so many people do? Example below

http://www.thedieselstop.com/forums/f47/...mission-198641/
 
I have a ATS 4R100 Stage 2 transmission in my 2003 F250 and want to change the ATF. Unfortunately I bought it used and don't know the type or brand of ATF in it. I called ATS and they said they normally recommend ATF +4 (yup, Mopar fluid!) in the 4R100!?! I questioned this and ATS said I could use Mercon V if I wanted but +4 was recommended. Being a Newbie, what do you experts recommend? Does the 2003 have a TC drain?
 
Originally Posted By: Jimbo7_3L
I have a ATS 4R100 Stage 2 transmission in my 2003 F250 and want to change the ATF. Unfortunately I bought it used and don't know the type or brand of ATF in it. I called ATS and they said they normally recommend ATF +4 (yup, Mopar fluid!) in the 4R100!?! I questioned this and ATS said I could use Mercon V if I wanted but +4 was recommended. Being a Newbie, what do you experts recommend? Does the 2003 have a TC drain?


Your transmission has aftermarket frictions in it, They probably do all their testing using ATF+4 & found it to work best (In their opinion) with the Pressure/Accumulation/Hydraulic modifications.

ATS likes to use Alto Red Eagle frictions, They are compatible with ATF+4 along with Dexron & Mercon fluids.
I would run a good synthetic Dexron/Mercon like Redline D4.

Your torque converter could be a aftermarket "Billet Cover" unit....You will need to visually check for a drain plug.
 
Clinebarger,
Thanks for your comments. I heard back from the original owner and he said he used Royal Purple ATF +4 when he installed the trans. I will check for a drain plug. If there is no way to drain the TC would I be the safest to keep to RP ATF +4 or could I mix with any other high quality ATF +4? I read on the Dodge forums that RP is not licensed by Mopar.
Thanks!
 
Royal Purple get's roasted pretty good on this site, A lot of the "boutique" oil suppliers don't bother with OEM licencing. I have had customers use RP ATF with great success.

Now that you know what ATF was used......No reason not to stay with it
 
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