2003 Silverado, Can I use Mercon V?

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1,200
Location
Missouri
My Silverado has 21,000 miles and I am planning a trans fluid change at around 30K. I have enough black bottle Motorcraft Mercon V to do a proper change if it is OK to use in place of Dex III. Several questions: Is Mercon V suitable for a Dex III application? I have read of a change of additives in Motorcraft Mercon V additive relating to seals when the bottle was changed to red. Should I even use the black bottle MC Mercon V? My truck has a very easy life, very light duty use. Should I change the fluid at 30K or wait? Thanks
 
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2,098
Location
The Rocky Mountains
Dex III or Dex VI would be good for you...I personally would Craig's list the Mercon V and not use it. Change your fluid at 50k or before 2011 (your fluid is getting older and potentially oxidizing as it lives its easy life).
 
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5,917
Location
Waterloo, ON
Check out this letter: THOMAS R. SMITH Technical Director, Valvoline Brand June 7, 2004 To Whom It May Concern: Valvoline has received several inquiries regarding the topic of MERCON V ATF and its use in various vehicles beyond those requiring DEXRON-III, MERCON, or MERCON V approved products. In response to these questions Valvoline has issued the following statements: Valvoline supports the use of MERCON V ATF in a broad range of transmissions beyond those requiring DEXRON-III, MERCON, and MERCON V fluids including those where the following fluids are recommended: o GM DEXRON II o Allison C-4 o Chrysler ATF+3 or ATF+4 fluids o Toyota (and Lexus) Type T, T-III or T-IV fluids o Mitsubishi Diamond SP-II or SP-III fluids o Hyundai o Honda ATF-Z1 fluid (except in CVTs) o BMW LT71141 or LA2634 fluids o Nissan Matic-D, Matic-J, or Matic-K fluids MaxLife ATF is recommended for the new 5 and 6 speed transmissions, except the Ford 5R110, Ford 6RXX, and the Mercedes Benz W7A700 (7G-TRONIC) which all require a low viscosity Automatic Transmission Fluid. Valvoline has conducted in-house testing to support MERCON V ATF performance in these transmissions. However, it is important to note that these vehicle manufacturers have neither evaluated nor approved MERCON V ATF. Valvoline stands behind all of its products, including MERCON V ATF. Use of MERCON V ATF in transmissions where recommended by Valvoline WILL NOT void the vehicle’s warranty. In the unlikely event that any transmission was to be damaged as a result of the use of MERCON V ATF, please contact Valvoline at 1-800-Team-VAL. Valvoline does not recommend MaxLife ATF for use in continuously variable transmissions (CVT’s) or in automatic transmissions where Ford Type F is recommended. Sincerely, Thom Smith Technical Director Valvoline Brand
 
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5,917
Location
Waterloo, ON
If you read between the lines of the above letter you know it's fine to use Mercon V where Mercon or Dexron III was used. They have to watch what they say for legal reasons. I call the tech line at Esso and asked about using their Mercon V in a Dexron III application. I was told it is a good replacement for Dexron III but but they can't say that on the bottle for legal reasons. You are going from a mineral ATF ( Dex III) to a semi-synthetic fluid
 
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4,370
Location
MS
The black bottle Mercon V (a newer formulation than red bottle) was specifically formulated to be backwards compatible in Mercon apps, so I think by default it will be perfectly suitable for a Dexron III app. Use it, it's one of the better Mercon Vs on the market for $$/performance, IMO. Motorcraft MV / Mobil 1 MV / Valvoline MV / Castrol MV Density @ 15º C kg/l; 0.863 / 0.846 / 0.860 / 0.858 Density, lb/gal; 7.19 / 7.40 / NA / 7.15 Flash Point, COC, °C; 196 / 200 / 190 / 180 Viscosity: cSt @ 100°C; 7.5 / 7.4 / 7.4 / 7.4 cSt @ 40°C; 33.2 / 36.3 / NA / 35.0 cP @ -20°C; 1,100 / NA / NA / NA cP @ -40°C; 10,000 / 10,040 / 10,000 / 12,000 Viscosity Index; 205 / 176 / NA / 185 Pour Point, °C; -48 / -41 / NA / -31 As you can see Castrol is weaksauce, I'd pick the Motorcraft out of that bunch (and I did). \:\!
 
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6,388
Location
Washington St.
Get Dexron-VI. It was made for your transmission. We know that MerconV has different friction modifiers than Dexron-III for different clutch materials. We also know that many blenders are using near-universal additive packages that work quite well in most transmissions. But...your Ford Motorcraft MerconV is likely blended strictly to Ford's spec, not a universal fluid. Get Dexron-VI.
 
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8,373
Location
Texas
 Originally Posted By: Ken2
Get Dexron-VI. It was made for your transmission. We know that MerconV has different friction modifiers than Dexron-III for different clutch materials. We also know that many blenders are using near-universal additive packages that work quite well in most transmissions. But...your Ford Motorcraft MerconV is likely blended strictly to Ford's spec, not a universal fluid. Get Dexron-VI.
X2. Use what GM recommends and that is NOW Dexron VI.
 

ledslinger

Thread starter
Messages
1,200
Location
Missouri
That's 6 posts saying use it, and 4 suggest using Dex VI. BTW I paid $1/bottle for the MC Mercon V. If I read this correctly, the Mercon V is better than Dex III, but the Dex VI is better than either. If the the Mercon V is better than Dex III, then it is good enough for me. I realize it isn't the ultimate fluid for a Dex III application.
 
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Messages
2,097
Location
kansastan
I wouldn't lose any sleep over using Mercon V in a Dex III application. It will work fine. If I had the stuff laying around, I would probably use it as such. But if I were going to go out and buy ATF for a DexIII application, I'd do with the cheapest DexVI available. That's the most bang-for-the-buck IMO. My 1994 Corsica's 4T60E works perfectly on dexron VI- it's had DexVI in the tranny for the last 30k miles. 170k total on the transmission. But the wife's '01 Chevy Lumina didn't like the DexVI so much. I ran Dex VI in its 4T65E for about 30k miles, and I never liked the full-throttle 1-2 upshift- way too soft, kinda slipped then grabbed. Did a full flush with Allison Transynd and the shift improved a lot. Shifts like it ought to, no slip & grab at all. 198k total miles on the tranny.
 
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