Whats the differance between these ATF(s)

[Wetpavement]

DEX-MERC and MERCON V? I've heard its a bad idea to run the first in a 4r100. True?

[Dietoremain]

uh thats the other way around.. the 4r100 was designed to run on dex/mercon III not that new crap. thats what i run in mine. chevron MD3.

[GreenF350]

Yup, what he said. Dexron/Mercon III is what you want for a 4r100. Ford SAYS (or at least used to...haven't checked in awhile) that Mercon V met all the requirements for the 4R100, but there are more than a few people that disagree. I have no personal experience, but I wasn't going to take a $4,000-$5,000 chance. Do a search, there were a few threads in the past that have some extensive discussion on that subject.
-Aaron

[mas360]

A lot of folks are saying Mercon V is detrimental to the 4R100 due to seal material not compatible with new specs in Mercon V. If it is a recently rebuilt 4R100 it should be ok as new components now are made with materials not damaged by Mercon V.

I play safe and use Dexron III as originally called out in vehicle manual. It is also cheaper than Mercon V.

[ianstew]

yep, i wouldnt run M V in a 4r100 or e4od, i beleive napa's transmission fluid is still D/M III

[GreenF350]

I had heard a whole ago on here that they were no longer making Dexron III and people were buying it up to make it last, but I haven't had a bit of problem finding Dexron III anywhere I look. My last "batch" was Valvoline (the same company that makes NAPA oil....or at least used to when I worked there.). Seems to me like they are still making it, but they might have had a TON of overstock I guess.
-Aaron

[Dietoremain]

Originally Posted by GreenF350

I had heard a whole ago on here that they were no longer making Dexron III and people were buying it up to make it last, but I haven't had a bit of problem finding Dexron III anywhere I look. My last "batch" was Valvoline (the same company that makes NAPA oil....or at least used to when I worked there.). Seems to me like they are still making it, but they might have had a TON of overstock I guess.
-Aaron

my bud gets it by the 5gal bucket..lol its not expensive and you can get it very commonly alot of companies still make it such as chevron.