4R70W / Mercon V / Dextron III

[The Dummy]

Howdy, Folks. This is only my second post on this forum but I have been enjoying reading it for several months and have reaped some very helpful information herein. Maybe, someone here can enlighten me on my most recent dilemma.

I have a 2000 F150 Supercab with the 4R70W transmission. The owner's manual and the dip stick unquestionably say that Mercon V is the transmission fluid that this transmission uses. I had my transmission/torque converter fluid and filter changed about 4000 miles back. The truck had 25000 miles at the time. At 3000 miles after this service, a stutter developed as shifting occurred from 2nd to 3rd and again when shifting from 3rd to OD. This was with light throttle and with RPMs low with load increasing.

I discovered today that the shop that changed the fluids used Dextron III instead of Mercon V. I believe that they believe that the two are interchangeable. I am not sure that they are. I have researched this and other forums and have not yet discovered this exact comparison. I simply need to know if Dextron III is a suitable substitute for Mercon V.

Thank you all for your help.


George

 

[Not the Autorx Frank]

Nope, not good. mercon V has much more friction modifier. I would change it out to a Mercon V. I run Redline d4 or Amsoil atf in my 150. Should help the shutter.


http://www.redlineoil.com/products.htm

http://www.amsoil.com/products/atf.html

Later

frank

 

[Ken2]

Most ATFs are combination Dexron III & Mercon, not Mercon V.

If the shop won't do a free complete change to Mercon V for you, try a bottle of Lubegard green bottle supplement. Lubegard claims it converts Dexron III/Mercon to Mercon V. It's worth the price to see if it works.

Those folks at the shop you went to are idiots...or don't have the backbone to admit that they made a dumb mistake.


Ken

 

[Ray H]

Yeah, George, Dexron III and Mercon V fluids are directly interchangeable - in your brother-in-law's car whom you despise. In your truck, though, the sooner you get that Dexron III out of your Ford trannie, the better. The people at the shop that did your fluid change weren't idiots at all. They were greedy crooks. Unfortunately, many independent shops like to stock bulk Dexron III and put it in whatever rolls in because doing so saves shop space, inventory hassles, and MONEY. They may or may not put a friction modifier supplement in. If they do, it may or may not work as advertised. And, if the supplement appears to work, it may only be delaying inevitable damage down the road that's unlikely to be associated with the independant shop's prior service. I have a lot of respect for Lubegard's products, but in this application I believe you're better off with genuine Mercon V spec fluid. After a flush or at least three drain/refill cycles, expect several hundred miles before the juddering is elliminated. (Whatever Dexron III remains after three drain/refill cycles will be too diluted to be a problem. It, too is friction modified, itself - just not as much.) From what I've read here and other forums, it seems that Ford trannies requiring Mercon V are about as finnicky as Chrysler trannies requiring ATF +4. Both manufacturers' trannies can be ruined with the wrong ATF, and both require their respective proprietary spec very highly friction modified ATFs to work long and reliably. At least with Ford, you have several Mercon V OTC ATFs to choose from. Not so for owners of Chrysler vehicles requiring Chrysler ATF +4 ATF.

[ August 19, 2003, 12:42 AM: Message edited by: Ray H ]

 

[BruceB]

I also have a 4r70w in a 2003 F150 & would like to swap over to synthetic at my first fluid change. I see that Redline & Amsoil make a Mercon V but which seems to work better?

 

[metroplex]

Amsoil ATF can last at least 50k miles and meets and exceeds Mercon-V specification.

Redline D4 ATF also meets and exceeds Mercon-V spec (on the back of the bottle, their website needs updating).

I know of no other FULLY SYNTHETIC ATF that meets/exceeds merc-V.

There are plenty of Merc-V ATF Synth blends at Walmart:
Pennzoil MP ATF
Quaker State 4x4 Synth Blend
etc...

I would go with Amsoil as its less expensive than Redline D4.

 

[MNgopher]

As others have stated, your tranny needs a Mercon V fluid or it will shudder. Mercon V was released to address this exact issue in these trannies.

I'd get rid of the fluid in there and put in a fluid that meets the spec. I'm not too crazy about the Lubeguard additives, but maybe they work, maybe they don't.

If it were me, I'd drain it ASAP.

 

[The Dummy]

Here is an update on my shudder dilemma.

It was not caused by the transmission at all. It was caused by a bad coil on #5 spark plug. Once replaced, the truck operates great.

However, FWIW, before I discovered the bad coil, I pursued the problem as though it was caused by the transmission. The shop that changed the Mercon V for Dextron III had already had me add a couple of ounces of Shudder Fix which is made by the same company that makes Lubeguard M-V. I called the company and after talking to someone named Pat, I added 20 ounces of Lubeguard M-V and then, drove the vehicle a little over 800 miles with the shudder becoming very noticeable with temperatures over 85º and noticeably less when the tempts were under 80º. This led me to suspect a coil. When checked, it was discovered that was the cause and when the coil was replaced the shudder stopped and power returned. I am still running the Dextron III with the 2 oz. of Shudder Fix and the 20 ozs. of Lubeguard M-V and so far, all is well and working fine.

Thanks to all here for the advice given after my original post and thanks to Pat at International Lubricants for his interest and support.

George

 

[widman]

I would still change out the fluid. I do not believe in miracle snake oil.

 

[The Dummy]

widman , thanks for the reply.

You have roused my curiosity. Will you be a bit more specific? If you know something about these products that I should, I truly want to know what it is because at this point, I cannot determine it they have helped anything or not.

Thanks in advance.

George