Wanted to ask you guys what the CORRECT tranny fluid that should be used for dents. The level is fine in my '79 F100 Ranger, auto tranny, but need to know for future reference. Should Type F be used or Dex/Merc? I also have an '86 F150 XL with auto tranny and I have always used Dex/Merc and all has been fine. Will using one over the other create issues with the tranny in dents? I believe I have the C6 tranny in both my trucks, but not positive.

 

Mercon is what it (1979) "officially" calls for, but type F will produce firmer shifting. Firmer shifting equals a happier engine.

And besides, real men use Type F.

Josh

 

what year was type "f" required for?

 

Ive always used type F in my 78 c6.

 

Type F introduced 67 until 77, but was used in some applications after 1980.

I personally would use Type F in all C4, C6 and FMX transmissions regardless of year.

Josh

 

My 2 cents: I see a lot of guys putting lukas etc. type fluids in their transmissions and I recommend against it. they say that is firms everything up. which is does but thats cause it breaks down slow. With that it amplifies the slippage issues when is breaks down and makes it all worse in the end. Your better off using a synthetic atf. Valvoline makes a product called maxlife for atf and engine oil, its a conventional oil with synthetic property. Good luck and thats my 2 cents.

 

Since I'm not sure what is in there, guess the best thing to do would be to drain tranny fluid and start from there. What, though, issues could / would mixing Dex/Merc & Type F create?

 

Look at the dip stick. It will tell you what to use. Either it will say type F or Mercon or it will give a spec number. If it's a spec number, write it down and when you go to the parts store look on the back lable of the bottle, it will have the spec number there.

 

Not much if its a couple quarts of either mixed in the batch, but I wouldn't want 50/50.

Josh

 

Thanks, guys, appreciate the info. As always, all you guys are right there to help out.

 

I know that if you need to look up anything you can get on autozones web site and for free start an account to use there maintenance info and that will tel you. There isn't any information on ford trucks before 75 or 76 so you can find what you need as far as fluids.

 

I would just use type F.The only difference between Dexron/Mercon and type F is type F has an anti-foaming agent in it. Have you ever heard of B&M trick shift? It's a racing trans fluid that B&M sells and it's blue. It's type F with blue coloring.

When I got into building transmissions back in the late '80's, a very good builder told me this. For the last 20+ years I've been building transmissions, I use type F in them. Ford, Chevy, doesn't matter. The only draw back is it's getting harder to find. The only damage to the transmissions where mechanical failures. (broken cases, shattered planetaries, broken spragues, etc. All the clutches looked like new when we tore them down. These were high horse racing applications we were playing with. I still use type F in my racing transmissions.

This is just my experience, take it how you want to.

 

Absolutely No lie, cheap tractor hydraulic fluid is the best thing to put in C6's for longevity and correct shifting.

 

Shell Donax TC hydraulic fluid, spec oil for most Caterpillar construction equipment and it also Type F without the red dye.

Josh