Mercon 5

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Mar 14, 2008 | 07:11 PM

KAWTECH

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Mercon 5

Does anyone know what would happen to an 4r70w trans if mercon 3 is used instead of mercon 5?

Mar 14, 2008 | 07:17 PM

Bobby82490

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From: N. Fort Myers,FL

Nothing, they used to use mercon 3 until ford changed the recommended fluid to mercon 5.

Mar 14, 2008 | 08:24 PM

KingRanchMan02

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From: Louisville, Kentucky

Your dipstick will identify what your transmission originally used. Mercron V is what you want if are doing a complete drain and fill. BTW, thee is no such thing as Mercron 3. There is a Dexron 3 which is a GM spec fluid. Mercron or Mercron V are Ford spec fluids and is all that you should use. Mercron is being phased out and eventually everything that used Mercron will use Mercron V. Good luck!

Mar 14, 2008 | 08:49 PM

steve(ill)

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KR is right. Some older fluids meet the Dextron III and the Mercon spec and are listed as both. The newer oil is MERCON V and is synthetic and has additional properties. IF you put the old oil in the new trans, you might get some poor shifting or transmission shudder, etc. Wont fail, but not idea to use.

Mar 15, 2008 | 12:14 AM

advocate

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i made this mistake - parts counter guy assured me it was the right stuff.... it made the shifts very mushy, felt like it wanted to slip. Did not feel good at all. If it calls for Mercon V, then use it. It's work the few extra bucks and is a very good fluid.

Mar 15, 2008 | 09:15 AM

superdutymj

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From: La Crosse, Kansas

Don't cheap-out on lubrications for your truck. The little bit you save isn't worth the big money you have to spend when something fails.

Mar 15, 2008 | 06:26 PM

KAWTECH

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Quote:

Originally Posted by superdutymj

Don't cheap-out on lubrications for your truck. The little bit you save isn't worth the big money you have to spend when something fails.

No intensions of cheaping out on my truck. The problem I have is the tranny shop put in mercon instead of mercon v. They are going to remove it and put correct oil in. I'm wondering if I'm going to have any latent problems.