Which fluid for TH350?

[grzewnicki]

I have heard that the type F fluid is a little stickier, providing better band and clutch clamp up. Heard this in the late 70's early 80's, Type F was I believe specifically made for Ford trans (it had no friction modifiers in the formula), you could use F in GM trans but never use Dexron in Ford trans.

 

[CorkyE]

Old hot rod myth from back in the day was to run type F because it made the transmission shift better. This was supposedly because type F friction modifiers would let the clutches grab quicker and harder. I tried it on one of my TH350 builds and didn't see any gains. I smoked that transmission build (and others) on happy gas. Finding a good builder cured that ill, and used Dex/Merc III. If your trans guy says he set it up to use type F, then use it. John Deere Hy-Gard seems to be the go to for a lot of drag racers, but TQ and transmission build is compensated for this fluid.

 

[ChevyReb]

I think back in the '80s B&M kits said to use type F on rebuilds with their shift kits. The builder I used then told me to use that so I did. But it had to be a new build as you didn't/don't want to mix dex III & type F.

 

[mallard]

I use type F in my TH350 that's been designed / built for Drag racing with a Pro Tree Transbrake and reverse manual valve body

Ok, quite a bit different situation. I sure wouldn’t try type F trans fluid in a stock turbo 350.

 

[doug m]

STEP 28. Lower vehicle but keep the
rear wheels off the ground if possible.
Add 3 quarts of proper transmission
fluid, or B&M Trick Shift
to the transmission. While Trick Shift
is superior in heat capacity, lubrication
and friction material performance, if
Trick Shift is unavailable be sure to use
Ford Type F fluid. this is out of b&ms install guide for higher performance apps.

 

[jakeshoe]

Type F is old school fluid.
Dexron and Type F will mix fine.

It's really not critical, especially on a TH350.

 

[sandlapper]

And, if your brand of street auto trans has a lockup clutch --- and if trans is bucking in/out of lockup --- aka Shudder aka Judder --- common cause of that annoying condition is the Friction Modifier component within its fluid has worn out, packed up and left.
May seem counter-intuitive, but that Friction Modifier is in there to help the lockup To Slip; it's supposed to slip in & out of lockup --- should Not have a Hard transition (buck/shudder) between the two. And yes, the FM simply Does wear out. You can either replace all of the (perhaps pricey) fluid or renourish it with a dose of Friction Modifier concentrate --- a very good one that's widely available is 2oz tube of pn 19619 Instant Shudder Fixx; by Lubegard.