Atf

[GsxrMike]

I need to fill my tranny and I was wondering what kind of fluid to put in it. It is a th400 with a shift kit installed. I filled with generic stuff but since I left it outside with a funnel in the fill tube in the rain I had to drain it. I was thinking of using trickshift or royal purple but didn't know what would happen. I want the thing to last as long as possible. Tia...

 

[gone huntin]

If water got into it then you might want to change the filter in it before you fill it w/ fluid. Better safe than sorry, just my .02

 

[k20]

I usually just run the advance auto brand crap. The trickshift fluid is really only ford type f. You can actually run that in your 400 if you want a slightly snappier shift.

 

[original balzer]

I was wondering about ATF recently too. Am I blind or is type f and regular ATF hard to find? You know before dextron/mercron you had either type f or regular ATF. Do you use the new stuff in an old transmission? Like dextron/mercron in a old th350 or th400 or power glide for that matter?

Excuse my ignorance I havent really looked hard for it, My 61 has a TH350 and I noticed at gas stations they only carry dex/merc.

My 77 has a th350 as well but I have never had to add any to it its always on the full mark. Other than that I havent owned any automatics for a long time.

 

[k20]

Dex/Merc is what most people run in the gm automatics. IIRC dextron was the gm stuff, mercon was a ford type, and they were apparently similar enough to fill both voids. The type F is an older type fluid (again going off memory) but if you run it in a gm trans it will make it shift harder. From how it was explained to me, the gm valve bodies control the shift properties. The ford type f fluid had the shift properties in it instead of the valve body, so if you run both you get hard shifts.

Again, some of that may be wrong, but to the best of my memory it is correct.

 

[GsxrMike]

what about adding one quart of type f into mercon/dextron. I had a ford guy tell me that would give me a snappier shift. I don't want a tranny failure because of something stuipid like mixing fluids. Wouldn't running synthetic fluid reduce mechanical drag on the drivetrain? While I am at it, what should I run in my 208 and axles?

 

[MaxPF]

Dextron II or better is all you need to run. FWIW, the later Dextron flavors (III and up, IIRC - definitely V and up are) are all synthetics anyway. One thing I have noticed is that the Dex V and up stuff (in my case, Valvoline Max Life) shifts noticeably softer than the II and III. I adjusted my TV cable out a bit to compensate, and the result is quite nice. The later stuff is supposed to be more resistant to oxidation and thermal breakdown, which are what kills auto tranny fluid, so IMO it is a good thing to use.

 

[boz42]

I run type F fluid in my T-400 per my transmission man's direction. Type F has a friction additive in it so it makes the clutches bite harder. Ford type f fluid has the friction additive because their older transmissions used bands instead of clutches. Bands need the additive to work because they do not have as much surface area as stacked plate style clutches.


I don't know about mixing them. Type F is the only thing that has been in mine.

 

[dyeager535]

*DEXRON* has no T in it.

Dexron is backwards compatible for all types AFAIK. I think they are up to 4 or 5 now for new stuff.

If you want firmer shifts, type f. Heard it from multiple builders and rebuilders. It won't hurt your trans to run Dexron, but for firmer shifts use Type F.

*Personally* I'd run Dexron unless I was using the vehicle solely off-road, towing, or drag racing. If I wanted firmer shifts, I'd do it with a shift kit of some type.

 

[MaxPF]

*DEXRON* has no T in it.

Doh! Busted .