727 fluid

[dans76sport]

I am putting a 727 in place of my 833od, and am wondering what fluid to use. This is a street/strip car that is seeing more strip than street lately.

[Blaine Peterson]

Opinions differ, but if it were my car for the use that you stated, I'd use Type F fluid.

[deadhorse66]

Originally posted by Blaine Peterson
Opinions differ, but if it were my car for the use that you stated, I'd use Type F fluid.

Agreed. Chrysler recommended Dexron/Mercon III, but the type F will give you a faster shift and let the friction members grip more than Mercon. The F stands for friction!

[5th_Ave_Sleeper]

I thought the F stood for Ford
Opinions vary greatly on this subject here. Type F is alot thinner than dextron, which is why people say it shifts better. Personally I could not tell the difference in my car, so I now use Dextron III, because thats what it says on the dipstick

5th

[dwc43]

Type f fluid has more friction modifiers in it compared to the mercon 3 which replaced dextron 2. The extra friction modifiers provide for stronger tighter clucth lock ups. That's basicly the same stuff you get from mopar and after market dealers to put in the gear oil when using a sure grip rear end. It too is just a friction modifier to keep the sure grip clutches locked up. If it's not added to the gear oil the sure grip will eat the clutches out and you go no where quick.
I prefer to run TCI fluid in my race trannys.

[concord997]

Howdy, I just got a 518od, and now, I see there is a 833od. What's the difference, Strength? I'm just considering the swap, But.... Thanks, Don

[dwc43]

518 is the auto based on the A-727 the A-833 od is a 4spd that had the 3rd and 4th gears swapped to make 3rd one to one and the 4th gear an od.

[dave571]

Opinions definately differ.

I've tried both, and not noticed a difference(at least in cars with shift kits)

Even Fords haven't used type F since 79, so I don't think I want to use it either.

The reason for the different fluid, in the fords, was the seals in the early fords were "flat" type seals, while everyone else used "lip" seals.

To each, thier own.

[concord997]

Thanks dwc43, Is either one any stronger than the other? I do have some power, Maybe 320 hp-+ and I don't race it. I like passing and hwy power. Don

[dwc43]

4spd od wont break like the a 518 will. The straight shift will take a lot more abuse, but I'd bet to say the 518 has some better gearing for you. But then again you said you dont race it so it might work for you. Kinda a tose up there. I have one behind a 360 and enjoy it. Course you could always opt for the A - 833 4 spd standard with out the od and get better gears. Guess this porbably caused more confusion ... huh.

[John Kunkel]

Even Fords haven't used type F since 79, so I don't think I want to use it either.

Type F dropped out of favor because of the introduction of lockup converters throughout the line, type F isn't compatible with LU converters.

The reason for the different fluid, in the fords, was the seals in the early fords were "flat" type seals, while everyone else used "lip" seals.

Seal design has nothing to do with fluid selection, type F simply has more aggressive friction characteristics, something Ford decided they needed for their transmissions. Type F also has a more potent additive package with more detergents to deter the buildup of varnish on the valves.

To each, thier own.

That's the bottom line, type F will allow the friction surfaces to slip less (even if you don't feel it in the seat of your pants) at the cost of some lubricating quality. The slight loss of lubricating quality also makes type F a bad choice for overdrive transmissions where the geartrain is in use the majority of the time.

[concord997]

dwc43, You just communicated, with an idiot...me. I just realized the 833od is a "4spd" DAH!!! Ok, I'm back on track. I'm thinking, 3.55s for the rear, and that should do it for me, all around. Right now I have 2.94s. I'll get milage and runability. By the way, the suffix "F" use to mean (50s-60s) Ford, and Chrysler prods. used it also. GM used the dexron 2. I think the "F" is now for friction. Thanks again, for the come back, Don

[dave571]

Aren't differences of opinion fun?

[1972roadrunner]

hmm...i don't use F or the others mentioned... i use B&M Trick Shift in my 727... it's blue instead of red...and i like it. we put it in my dads chevy truck (93, all stock) and it actually barked second after the fluid change. it wouldn't before... i need to tune it up though. it's got over 120,000 on that stock 350 --> never rebuilt. last tuned up over 50,000 miles ago. (lotsa highway driving! every weekend...about 120 miles)

[John Kunkel]

B&M Trick Shift is formulated from type F base stock.