transmission fluid ??

[Bobby]

Anybody know what to use instead of Type A Dexron transmission fluid. I can't seem to find that. I want to change the transmission fluid in a '92 Nautique Excel.

[wesgardner]

HeyBobby,
Crozet, is that the Crozet just outside C'ville? I used to live at Miller School in the '70s and could go down to Morton's and get their "second" chicken pot pies for little or nothin'

Dexron should be very readily available, isn't it and Type F for Ford products the two main types?

Wes

[Bobby]

Yeah, Wesgardner, that's the Crozet. Morton's is long gone but the buildings are still there waiting for their next life.

I'm still not clear on transmission fluid though, is any Dexron ok even though it is now Dexron III and Type F. The manual calls for Type A Dexron or 20w oil.

[prestige]

A quick search and I found:

A few years back, there were only two types of fluid on the market: Type A and Type F. Conventional wisdom said that Type F was for Fords and Type A was for everything else. Conventional wisdom wasn’t all that accurate even back then, and today it’s completely out the window.

These days there are four main types of fluid on the market. And there are dozens of brands and styles to choose from.

Here’s a list of the different types of fluids, and the basic differences between them:

Type F — Yes, it’s still around, as a quick walk through at your local parts store will attest. The only think is, almost nothing uses it anymore. Type F was designed for Fords that used bronze clutches; the last trans made with bronze clutches was the Cruizematic, last used in the early ‘70s. Unless you’re talking about a classic car or an antique, you can be pretty sure your car doesn’t use Type F.

Dexron III/Mercon — This is one of the most common fluids on the market. Most GM and Ford units call for this type of ATF, as well as many imports. If your owners manual recommends any form of Dexron, or any Mercon — other than Mercon V — this is the fluid you want.

HFM-Style Fluids — HFM stands for Highly Friction Modified; it’s a fluid that provides different friction characteristics than Dexron III/Mercon. This fluid appears under a number of different names, including Chrysler’s ATF+ — also called 7670. Other manufacturers that use HFM ATF include:

• Honda/Acura

• Jeep/Eagle

• Hyundai

• Toyota/Lexus

• Saturn

• Sterling

Are these fluids interchangeable? They should be… logic dictates they are. But to be safe, always use the specific fluid the manufacturer calls for.

Synthetic Fluids — A number of manufacturers have begun to discontinue the use of organically-based fluids, in favor of synthetic fluids. Preliminary tests have shown that most synthetics have similar friction modification characteristics to Dexron III/Mercon, but with improved resistance to heat, cold, oxidation and sheer. In simple terms, synthetics last longer.

Synthetic oils are one reason why many manufacturers are also beginning to eliminate the transmission dipstick. Their feeling seems to be the ATF will last longer, so there’s no reason to let people interfere with the transmission and its operation. Will they work? Will synthetics really keep the transmission operating longer, without human intervention? Only time will tell.

CAUTION — Ford labels their synthetic fluid Mercon V, which can be a bit confusing. If the manual says Mercon V, it’s calling for the synthetic fluid; if the name is Mercon without the V, that’s the regular Dexron III/Mercon ATF.

Additives Alter Friction Characteristics

While there are many different types of ATF on the market, a few aftermarket chemical companies have come up with an idea to save repair shops and vehicle owners money. What they’ve done is develop additives that mix with standard Dexron III/Mercon, to alter the friction characteristics to match the other types of fluid.

One of the most common of these additives is the HFM additive. When added to Dexron III/Mercon, it alters the friction characteristics enough to allow you to use it in any transmission that requires HFM fluids.

This probably won’t affect you for adding a quart of ATF; chances are you won’t be able to get this additive anyway. They’re usually only available through professional sources. If you need to add a quart of ATF to your transmission, you’re probably better off using the factory recommended ATF.

But if you have your transmission serviced and the fluid replaced, the repair shop may use one of the HFM additives along with Dexron III/Mercon in your trans. That’s okay; these additives work just fine for altering the fluid’s friction characteristics.

However, if your transmission is still within its factory warranty, check with the dealer or a factory representative before allowing anything in your transmission besides the factory recommended ATF. Other additives or oils could affect your warranty.

[Bobby]

Wow, that's a lot of great information. Sounds like you are saying that I can use Dexron III, which seems readily available, since my manual calls for Dexron, Type A, ATF. Although it seems like most of the Dexron III's I see are Type F. I'm no longer under warranty so that doesn't matter. Thanks for the info Prestige! Any recomendation on synthetics?

[Ruune]

awesome, prestige! I've done some research into synthetic oil, but not ATF. Whats your info source? I'd like to do some investigating on synthetic ATF myself (unless you've got more info on that specifically). Anyways, thanks for the primer!