Dave, I recall a year or so ago somebody posted the technical reason why Mercon V should not be used in the 4R100. I can't recall the location and details. Read your owners manual. Ford says use only Mercon, not Mercon V or combination oils. Why would you risk your warranty and your transmission by believing a former Ford mechanic as opposed to Ford itself as plainly printed in your owners manual? Fords position is not a theory, its a fact. Most of us do not feel compelled to delve deeply into the engineering reasons why the auto companies use certain specifications for their vehicles, and there are a few after-market mods which make perfect sense to do. However, I have heard no justification for using Mercon V instead of Mercon, only a justification for using synthetic instead of dino oil. Go find a Mercon-only synthetic and use it. Keep your receipt in case you need warranty work on your transmission.
Warren

 

I just went and checked Auto Zone, they had the new stuff with Mercon V on the front. O'Reilly's had 10 qts. of the old stuff, had them order more to see if the warehouse still has old stock. Would like to get enough for one more change.

 

Went to 5 of our local AutoZones and all but one had the new Mobil-1 ATF. The one that had the old stuff had 16. They called around and found another that had 7 more. I have enough for my initial changeout and will slowly accumulate another 13 somewhere.

Schaeffer's oil, I have a contact to find out if they have mercon or mercon V type of ATF. I will call him tomorrow to find out and post it here.

 

More data i found on Schaeffers All Trans Supreme:
http://www.schaefferoil.com/datapdf/204SAT.pdf
Nut

 

I read that yesterday on their site and got confused when it mentioned Mercon V. I would have been perfectly fine if they did not list mercon V, and would have purchased a few buckets worth. the local schaeffer rep referred me to a Larry ludwig which will know if it compatible with our transmissions. I will be talking with him *** soon as I can.

 

I was looking at that last night. I have a call into a dealer about 30 miles away. I too am concerned about Mercon V rating. They must have something that's ok to use if Brian's Truck Shop uses it in their transmissions.

 

I agree......

 

OWNERS GUIDE
F-250/350/450/550
Super Duty F-Series
2002 MODEL YEAR
Page 237

"Some transmission fluids may be labeled as dual usage, such as MERCON and MERCON V. These dual usage fluids are not to be used in an automatic transmission that requires use of the MERCON type fluid. However, these dual usage fluids may be used in transmissions that require the MERCON V fluid.

MERCON and MERCON V type fluids are not interchangeable. DO NOT mix MERCON and MERCON V. Use of a transmission fluid that indicates dual usage (MERCON and MERCON V) in an automatic transmission application requiring MERCON may cause transmission damage. Use of any fluid other than the recommended fluid may cause transmission damage."

This is an exact quote. Of course, it is not from some ex-Ford master mechanic, a dealer 30 miles away, or somebody named Ludwig, Brians Truck Stop, or Shaeffers. Its just from the company that designed and built your truck, specified the fluid, wrote the Owners Guide, and WARRANTED the truck.

Warren

 

Just keep in mind that Brian gets rid of the factory clutch packs where the merconV does its damage.

 

Yeah that makes sense. Might be worth a call to Brian.
Nut

 

After I thought about it last night, I was wondering if that might be the case. Good to know.

 

Damaging the clutch packs....that is the quote I guess I needed to hear "cut and dry" on why not to use MERCON V. He wanted to drain and flush the system and reinstall MERCON V insted of Mercon III. I will have him put ONLY the Mercon III in when he does the Sonnax shift upgrade...besides, the folks from Black Cloud Diesel told me NOT to use the Mercon V with this upgrade......I guess someone had to bang my head against the wall to show me, but I like to question things just in case there might be another way to do things......Thanks for all the help..Dave

 

Sorry for reviving an old thread, but I am in the process of replacing the trans cooler lines on my 2003 F350 6.0 and came up with this thread when searching on which trans fluid to use.

Just went through the coolant ordeal and settled on Rotella ELC NF for the coolant in the truck. Thing is, Ford recommends the gold Motorcraft crapola and I think we can all agree that it is a bad idea to use that stuff or anything else that might result in silicates dropping out.

Just thought I would put my nickel's worth in here. Now, back to trying to figure out which ATF to use in the trans. Heck, after reading this thread I need to figure out which trans I have in the truck. I want to make sure it is a 4R100. Think I read last night on AllData that there is also a Torqshift trans that was used.

Just one more thing to learn about this truck.

 

You don't have a 4R100 if you have a 6.0 engine, you have the 5R110. You need to check the 6.0 forum.

 

Just FYI....I recently bought a 2003 E-350 with the 4R100 transmission in it....295k miles on it! Tranny shifted great, and fluid looked/smelled great too, but I went ahead and changed the filter and fluid, and I used Mercon V. However, now the vehicle has a shudder when it is in gear but not moving, or just idling along at 2-5mph. I am 95% sure it is the Mercon V that the tranny does not like. I am going to swap it out for regular Mercon + some Redline D4 upon someone else's reccomendation, as well as a bit of Lucas tranny fix. My plan is to leave it in there for 20k miles if the shifting is good. If it's only a minor improvement I'll count it as a "flush", and again change but this time to 100% Mercon. Hopefully all works out.