Type F Fluid vs. Dextron my Impressions

[bigblack'74]

I tested both of them in a new TH-400 with stock clutches, B&M shift kit, deep finned pan, adjustable shift modulator, and big cooler.

type F: The first thing I noticed is the rock, rock hard shifting. It was busting 36's loose into 2nd gear. It would also hold longer(from upshifting) with the kickdown switched engaged. The second thing I noticed was it seemed to get thicker when cooled down, as it made the pump whine when first started. A possible problem I noticed, was that as near redline rpms, either the clutches started to slip a small amount or they started to chatter. This was actually what caused me to end the test with the type F. One other thing I noticed was the type F ran hotter than the Dextron.

Dextron: The shifts with dextron were not nearly as hard, but just as, or more precise than with Type F. It wont hold as long in a certain gear as with type F either. When I changed to the dextron the whining is completely gone and it runs cooler. The most obvious difference is that at near redline the clutches do not slip or chatter, and make for a very pleasant manual up shift.

I feel the only reason to run type F in a th400 in a FSJ is for towing purposes. It is just far too abrasive and agressive for the driver(and the little woman if you happen to have one of those;)) The dextron holds up better when I get to red line, which is where I get to alot of the time. Not to mention crisp and precise shifting with no lag, and no BANG. hope that helps someone might be wondering about that :thumbsup:

[68glad]

personnally I would NEVER run type F in any transmission. It is inferior to dexron.

[Gil]

My mechanic ordered me to ONLY use Dextron (3, I think)...

[shimniok]

I would've sworn all the factory information says use only Dexron in TH400 and TF727 ... ?????

[bigblack'74]

Yeah I am sure it does, but people have used TYPE F as " the poor mans trick shift for years" ... lots of drag racing people use it all the time

I would've sworn all the factory information says use only Dexron in TH400 and TF727 ... ?????

[shimniok]

I did some searching on da interweb... sez the Type F is for ford stuff which used different type of clutches that tended not to hold as well under lower pressure so the F is meant to generate -- I gather -- higher line pressures for that purpose. That jives with the review above. One guy out there somewhere posted about using 50/50 mix. Interesting, learn something every day.

[Stuka]

personnally I would NEVER run type F in any transmission. It is inferior to dexron.

There is nothing inferior about it. Its simply meant for Ford transmissions. Namely the older FMX/C4/C6/AOD and so forth.

[68glad]

There is nothing inferior about it. Its simply meant for Ford transmissions. Namely the older FMX/C4/C6/AOD and so forth.

When I say inferior I mean that you can run dexron in a ford tranny & it will work fine but if you put type F in a 400 or 727 it'll not perform as well.

[bigblack'74]

I did some searching on da interweb... sez the Type F is for ford stuff which used different type of clutches that tended not to hold as well under lower pressure so the F is meant to generate -- I gather -- higher line pressures for that purpose. That jives with the review above. One guy out there somewhere posted about using 50/50 mix. Interesting, learn something every day.



good info makes alot sense

[Chucks1911]

Yeah I am sure it does, but people have used TYPE F as " the poor mans trick shift for years" ... lots of drag racing people use it all the time

I've used it for this in the past. It will also "stiffen up" a Th 350 or Th 400 that is having issues.:D

[janie]

Dexron III for this girl. In fact at this point, I own stock in it.:)

[HOOT]

Dexron III for this girl. In fact at this point, I own stock in it.:)
:lol: I was wondering when you would chime in on this..

[beloth]

I've used it for this in the past. It will also "stiffen up" a Th 350 or Th 400 that is having issues.:D

what kinda of ratio would you recommend if your TH400 is starting to have "issues" like 50 / 50 or 1 part dexron to 2 parts type F??

[slackin']

where can one pick up dexron III?
the only thing Ive found locally (and Im currently using) is dexron VI.

[Chucks1911]

what kinda of ratio would you recommend if your TH400 is starting to have "issues" like 50 / 50 or 1 part dexron to 2 parts type F??

Well its not gonna be a "magic" fix but it can help you make it a bit longer till you either get rid of it or rebuild it. We used to do a 50/50 mix.

[710 Burner]

I have heard that if you put type F in a 727 it can cause a squawking noise in the TC. I have not experienced this myself.

[crispyboy]

I went the mobil 1 synthetic route - smooth shifting for me.

[misfittom138]

Uh oh. I think I use f. Coulda sworn the manual said to. Or maybe it's ATF+ and I'm confusing that because it has an f in it. I should check. :D

[jeepsr4ever]

F is like poor mans clutch chatter fix

[Lindel]

Continued use of a Type F (Ford) transmission fluid in your non-Type F (non-Ford) will result in a fully non-functional transmission.

Type F fluid uses friction modifiers that Dexron doesn't have or need. As stated above, works fine in older Ford trannies, but not in others.

[misfittom138]

Continued use of a Type F (Ford) transmission fluid in your non-Type F (non-Ford) will result in a fully non-functional transmission.

Type F fluid uses friction modifiers that Dexron doesn't have or need. As stated above, works fine in older Ford trannies, but not in others.

Then it can't be type f I have. I wouldn't have bought it if it said for ford use. :D