My BIL went to the tranny shop I usually use today to have his 01 Supercrew transmission fluid flushed and replaced. The kid they had doing the tranny fluid jobs was going to put regular Mercon in instead of Mercon V but my BIL caught it. I had my 02 Supercrew flushed and refilled there about 2 months ago and strongly suspect the kid may have put Mercon in mine too. The receipt just says "service 4R70W, flush, replace filter, add fluid and friction modifier". Couldn't get ahold of the owner til Monday (nice guy, competent, but dumb kid needs more supervision). How serious is it if they did put Mercon in it instead of Mercon V? The book says that Mercon and Mercon V are NOT compatible and not to mix them, and that dual use Mercon/Mercon V fluids CAN be used in transmissions calling for Mercon V but NOT in transmissions using straight Mercon. Should I demand they flush out all the fluid and refill with Mercon V to be sure? I've put about 4,000 miles on it in the 2 months since it was changed, mostly to work and back and light highway trips, but I have to make a long nearly nonstop trip to Sikeston MO this week and will start hauling hay soon. HELP I really need some advice here. THanks in advance. JR

 

who/what its BIL?
I would demand that the tranny be flushed again and that they show you the actual fluid they are going to use before they fill it. Are they using one of those vacum machines to change the fluid? I've heard that the shop should have a specific machine for each type of fluid too.

 

Thanks! I dunno what kind of machine he's got to flush. I've had a couple rebuilds done there and the boss does racing rebuilds/mods, seems to really know his stuff, the rebuilds I've had done have held together really well. He has some kid doing the light stuff now and he doesn't seem real bright. guess if you want something done right ya gotta do it yourself, or else watch em like a hawk.... talk to the boss Monday and see what happens, but I think I'm getting that fluid outta there either way. He should do it free, but if not just pay Ford to do it. IF the kid woulda wrote what he put in there on the darn ticket I wouldn't be in this mess. Course the kid gives me a different story every time I talk to him... told my brother in law they usually have Mercon V in stock, he just goofed and grabbed the wrong stuff. Later he told me they never have Mercon V on hand and have to order it from the AutoZone up the street, which is exactly what they did when my BIL caught him about to dump Mercon in his. Course if they DO have to order it every time, there should be a record. If they ordered some that day chances are better I have Mercon V in there, if they didn't order any, I'd bet it's regular Mercon. Anyway, I think it better go. I'd rather spend $150 to have Ford flush it out (if boss won't make it good) rather than risk a cooked tranny, and possibly void the warranties. Thanks.

 

I would have it changed out pronto, I had the exact same thing happen to me.

If you would like to try it yourself, check this out:

https://www.ford-trucks.com/article/...nsmission.html

 

I would get a Turkey baster and clear tubing to reach down into the tranny dipstick tube. I'd have a couple of witnesses, and video tape the removal of the fluid to clean glass container. Seal the container. Either keep it for problems down the road or send it off to a test lab now. I'd have them change the fluid. This is per a Ford dealership, you can only use a machine that is for Mercon V only. Best to drop the pan and change filter and fluid. In the owners manual it clearly states that dual use fluids cannot be used in these transmissions. The dual use fluid can be used in power steering* units filled with Mercon V. *If your transmission has Mercon V in it then the power steering unit was filled with Mercon V at the Factory.

 

Just remember that the drop-the-pan method won't address the fluid held by the torque converter.

 

Old thread, but WTH, I'll post anyway.

I went to the dealer to have my 2001 with 4R70W, flushed, but when i went to my mechanic the same week, we noted it was 1 QT low, so he added a quart of fluid....MERCON! my dealer about crapped and flushed the whole thing for free.