I have drained a couple E4OD transmissions and TCs in the past, and refilled them with Mercon V. During the short time I owned each vehicle, a '95 Bronco and a '95 F-250, each vehicle ran smooth as silk with Mercon V fluid. But I have heard since then that it is a serious no-no to use Mercon V in an E4OD. I also noticed that in the Owner's manual of my '98 F-150, while Ford specs Mercon V for the 4R70W, as would be expected, they still spec plain Mercon for the E4OD. So, what's the deal? Will Mercon V, or Mobil One's Mercon V compatible fluid, cause an E4OD to take a crap? If so, why?

As usual, thanks in advance.

VMM

 

Mercon V now per TSB from Ford Motor. (TSB's can be had here @ the top of the page, ALLData.com, Motorcraft.com and many other resources)

If your looking for posted TSB's - try the engines forum - I posted all the Ford Oil TSB's there. Use the search this forum feature to the right - don't search from the top - only after clicking on the forum of choice (best way to locate. - If you don't search that way, you'll most likley dead end).

I run that pricey AMSOIL now with a couple shots of Friction Modifier and a pint of 100% Syn rear gear lube in my E-40- Temps are down and its never shifted better.

Best thing I every did is talk to few older guys who's worked on trasmissions purdy much there whole lives..

FYI - The 98 was the last and only E4OD to recieve the updated seals to withstand the less tame Synthetics for that year. All can run Merc V now.

My 98 trans has close to 255,000 miles on her and hits without a pause..

Your doing the right thing

BTW - The 98 Oper Manual say "See Dealership" on change or flush w/E4OD Transmissions.

SIDE NOTE: I can't recall the website off hand but - WAIT!! I just remembered lol - The Diesel Garage website does a total E4OD rebuild w/color photo's if you ever need to dig into one. Great info there - can be very helpful...