A-904 shift kit

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joshua dewitt

joshua dewitt

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getting ready to tackle the valve body, I want firm but street able with the auto function, I do have a full ratchet shifter Hurst pro-matic2. as well. from what I have been reading , is the best shift kit to go with the Trans go TF-2? and does anyone ever change the springs in the governor as the 727 for higher shift points to make a difference to match the valve body? I
am planning on a 9.5" pft converter 2500-2800 stall. 3.5 gears
 
In a TF-2 kit, which allows automatic upshifts in Drive;
If the rear end ratio, and the governor, and the engine, are a matched set, then the KD system can usually be adjusted to get a comfortable upshift. These three are intimately related. But if any one of them (and especially the rear gear ratio) is not original or original-type, then they may get out of sync. Also driver preference may come into play, as well as useage.
If you have experience with the tranny before the shift kit goes in, you may already know if it is acceptable or not.
Cranking up the line pressure is a standard thing with a kit, and this will,by itself,delay the automatic upshift speeds. Changing rear ratios will also change upshifts speeds. Sometimes the two conspire to make the automatic upshift speeds too high, or too early, and it becomes annoying.Sometimes the auto downshift speeds get annoying. When these types of things present themselves, that's when a governor mod may be necessary.
I had a more or less stock 73 teener, and a matching tranny with a TF-2 kit and a 2400 TC. It came out of my dying Dart beaker, with a 2.76 rear.When I installed the teener/904 into my S for a winter combo, I installed a 3.55 behind it. And immediately the shifts went out of sync for my driving style and useage. I had to mod the governor twice,to suit me; once to swap out the weight, and once again to fine-tune the spring. It is a bit of a pita to do in-car, but the results were well worth it.
 
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sounds a lot like my combo. what did you do to the spring?, other option... full manual valve body
 
joshua dewitt said:
sounds a lot like my combo. what did you do to the spring?, other option... full manual valve body
Click to expand...

Sorry if I'm jumping in and interrupting, but adding more or heavier spring makes the shifts later in road speed (driveline speed)
Lighter or less spring makes them earlier.
Changing governor springs and weights moves all the shifting father up or down in the wheel speed ranges.
Changing springs in the valve body makes it possible to change the shift point for a single gear (like if the 1-2 shift is too early but the 2-3 is where you want it.)
You would then use a tighter spring for the 1-2 valve and leave the 2-3 alone.

What I did with my TF2 kit was to shoot for the middle range of the oil holes in the separator plate and it gave me nice solid shifts at higher throttle openings without being annoying at lower speed and throttle.
Say for example the instructions said the 1-2 oil hole could be as large as 80 thousands and it was currently 40 I drilled it to 60.
The kit for mine came with the option for an "at any speed low gear downshift" and I did want that.
With the ratchet shifter you REALLY have to mean it if you want the first gear downshift because you have to ratchet back twice in a row on the shifter to do it.
My car is pretty high geared, and I can drop it into first at 40-45 and have all kinds of instant horsepower and torque available with the RPM's
It puts the engine in the mid to high range of my cam instantly.
 
I had about 10 core transmissions. I checked a few governors until I found what I thought would work, and it did. Honestly, I can't tell you what to put in there. The stock parts might work fine for you. A lot of times this stuff is personal preference.
I had a stock 73 teener with just a little TQ on it and the TTIs with dual 3 inchers all the way.Plus the TF'd 904 with a 2400TC and 3.55s. The 3.55s spun the D/S up faster and the shifts were too early, and out of range of the TV adjuster. I figured out that the flyweight in the gov was too heavy. So I put a lighter one in and that got it into the ballpark. Then I wanted it to automatically downshift in the corners at about 12 to 15 mph, with just a moderate amount of pedal, so I could power through, without downshifting manually. I already had the PT downshift upgrade, so I just fine-tuned the gov with a spring change, so I didn't need to use as much throttle,in a higher gear. After the change, it would downshift into 1st,with just a small amount of additional pedal, instead of a lot of pedal. That took the herky-jerky out of it. Then by lifting off the gas I could let 2nd kick in. You can see how this is totally a personal thing,right? My right foot is now smoothly commanding the up/down shifts with a corresponding amount of synchronized power delivery. That is the sweetest street tranny I ever built.
At the time I was doing these things(early 2000s), I never dreamed I would ever be sharing this info, and so, never documented anything. Whenever I didn't like the way a certain thing was working for my driving style, I just went after what I wanted, like a bulldog, until I got it. In about 4 years, I had everything bugged out (engine,engine tune,trannys,diffs,suspension/steering/brakes, etc), and after that, I just drove it.
I had installed a TF kit with full manual option into a 69 Barracuda/slanty I had, in 1976. It didn't take long to figure out that full manual in city traffic was not for me. Since full manual was an option in this kit, I just swapped it to; automatic in D,mode. I liked that much better.So I'll never go full manual again. I also don't like a ratchet/only shifter for street duty.
Believe it or not, that sloppy factory console shifter worked just fine,most of the time.In either slanty or teener;for street work.
So you hear me saying a lot of I's, and that is because I have preferences. You may have other preferences.I hate to say wait and see, but the A&A parts are pretty pricey to buy and then find out you don't like it. It seems to me it wasn't very long ago and they were a lot cheaper. If you have a lathe, you can machine the stock one down to shift later,until you like it.
 
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AJ/FormS said:
I had about 10 core transmissions. I checked a few governors until I found what I thought would work, and it did. Honestly, I can't tell you what to put in there. The stock parte might work fine for you. A lot of times this stuff is personal preference.
I had a stock 73 teener with just a little TQ on it and the TTIs with dual 3 inchers all the way.Plus the TF'd 904 with a 2400TC and 3.55s. The 3.55s spun the D/S up faster and the shifts were too early, and out of range of the TV adjuster. I figured out that the flyweight in the gov was too heavy. So I put a lighter one in and that got it into the ballpark. Then I wanted it to automatically downshift in the corners at about 12 to 15 mph, with just a moderate amount of pedal, so I could power through, without downshifting manually. I already had the PT downshift upgrade, so I just fine-tuned the gov with a spring change, so I didn't need to use as much throttle,in a higher gear. After the change, it would downshift into 1st,with just a small amount of additional pedal, instead of a lot of pedal. That took the herky-jerky out of it. Then by lifting off the gas I could let 2nd kick in. You can see how this is totally a personal thing,right? My right foot is now smoothly commanding the up/down shifts with a corresponding amount of synchronized power delivery. That is the sweetest street tranny I ever built.
At the time I was doing these things(early 2000s), I never dreamed I would ever be sharing this info, and so, never documented anything. Whenever I didn't like the way a certain thing was working for my driving style, I just went after what I wanted, like a bulldog, until I got it. In about 4 years, I had everything bugged out (engine,engine tune,trannys,diffs,suspension/steering/brakes, etc), and after that, I just drove it.
Click to expand...

That's almost exactly what and how I went about it with my 904, and as soon as I got it all dialed in the front planetary set started coming apart.
Then I got to start from scratch with the A500.
 
AJ/FormS said:
TB
Did you ever take that 904 apart yet?
Click to expand...

No, and I probably never will unless there is a good reason for it. (like someone needs something from it)
Most likely it'll go to recycle heaven if not.
Do you need something?
 
yes it is apart, just go the Kevlar bands, and billet servo and pistons... need to get a few dollars up to get the overhaul kit with the read clutches and perf. steels. or do you guys think stock clutches ok, not a race transmission. rather spend the money in the v/b and t/q.... already vented the case to the rear webbing, as Paul from turbo action stated to do. I am also going to use Teflon seals on stator and input shafts. supposed to be better. not sure, I may have to sell the car in future, don't want to but too much more in it, I have over 20k in it now.
 
I'm not a fan of teflon seals, myself. I like the cast rings.They stay where I put them, during assembly, and seem to last a really really long time.
Welcome to the money-pit club.....
 
really, well then I can go with a cheep stock rebuild kit then. the scarf Teflon seals I was talking about use sizer rings tools for installation. but I guess there isn't any available that I've seen only scarf style(split). and that being so, it would be much cheaper anyways. does anyone prefer alto or eagle red clutches over waffle design? or about the same for durability if pressures are properly controlled form good seals and vavlebody?
 
I have limited experience with autos in personal cars, but at under 250hp(what I have run), just about anything has worked for me with a TF-2 kit, on the street.I've always run TF-2s. I'm a tightwad/poor-boy mechanic tho and have always been willing to pull stuff apart if it wasn't strong enough, for a do-over.I mean in,out,and rebuild can be done in a day;certainly a weekend. You might not want to take that approach.....I never had a problem with whatever aftermarket clutches.
 
what HP is this car to warrant higher shift points that can easily be done without touching the governor?
Use the TF2 kit.
Full street car, driven year round or seasonal? use the Reds, but skip the Kolene's and use standard steels. Are you bumping the direct clutch to 5 disks?
 
@ 400 hp... street driven. maybe track when I get the itch, I live down the street from the local drag strip.... will have to do it. using the standard 4 clutch, not going to all that modifying and buying another clutch housing, , I have it all ready. any way, why standard steels? and not kolene? what's the deal on that? so if that is the case I can use a standard kit ( cheep) for soft parts, and spend the money on good shift kit and t/q-verter.. I will use red clutches if I find them with in reason, or stockers cold work, already have a custom external spin on filter kit, an deep pan, and add on cooler up front.
 
Transtar there in Tucson, or WhateverItTakes in Phoenix has the Reds. Why no kolene's, because its more street driven than track, and the kolene coating wears off. No need to switch direct drum to get 5 clutches. Even at 400HP(flywheel or RearWheel?), I'd stuff 5 in there. Just need someone with a lathe to cut down the thick spacer plate. You upgrade the single spring on the direct piston too? Billet accumulator, what applylever ratio? billet strut too. Many little things to make it bulletproof.
I'm up in Phoenix, so message me if you want to go over any of this?

what RPM are you wanting to shift at in D?
 
spring upgrade on direct clutches? where do you get an upgraded spring at? what pressure difference? yes I have hd band strut, @400 at flywheel, and was thinking of going with pft? 9.5" converter.... sounds like a good combo, I would rather have lennys form ultimate converter but 900.00 is out of the question. hughes recommended their 27-25 I believe, but just off the shelf stock 11" remaned to 2500 stall unit. guessing shifts in drive 3000-3500 without pedal flooring it, planning on going tf-2 shift kit. hell, I don't go shopping, I usually just mail order everything, summit has a drop off point in front of my door step. hehehe, wife hates it.... but tcs has reds at difference thickness. so I just need to micrometer each clutch to get the same thickness? my steels look fine, should be able to reuse them, hell the clutches look near new too, but wanted to upgrade.... best to do a tf-2 shift kit, or buy a hughes, or tci street fighter valve body?
 
TF-2 shift kit. Plenty of places online to get the direct spring pack. Try coperacingtrans.com . John is a site sponsor, and a great resource for anything you need for the 904. Okay,what WOT RPM shift point do you want?
Give TCS Canada a try too. I've used their 3K 9.5 converter on 2 different cars. Works pretty good too. One was around 400HP with 3.91's the other close to 600HP with 3.55s. Changing from a 904 to an A-500 in the Dart(2ndcar, and one in my avatar), and Rusty at TCS in Havasu, is building me a 3K lockup converter, that won't break the bank.
 
Let me add a note about the Teflon rings if I may.
For one I would only recommend them for an experienced builder, because they are so damn easy to pinch and cut during assembly. (Even with shaping cups and covers)
The other thing I don't like about them is they eat into the metals they are in contact with more than iron rings believe it or not.
I have seen more worn out stators, ring lands and drum bores from Teflon rings over iron by a long ways. (especially with aluminum parts)
 
FWIW: Kolene isn't a coating, it's a metal treatment. The dark/black finish is a post treatment surface finish (black oxide), but the process is similar to case hardening (but with less warping). It's akin to a salt bath nitride operation and increases the surface hardness of low carbon steel to a significant degree by diffusing nitrogens into the surface. This can do several things: increase wear resistance, increase durability, reduce friction. Depending on how the process is applied, the reduced friction could obviously be a problem in a transmission but I'm assuming those that offer them know this and so they don't over-polish the parts (part of the kolene process is to polish the components - this is done to reduce the chances of intergranular corrosion, and rust in general, developing). If over done, the polishing can reduce the coefficient of friction pretty substantially, but it's also common to skip the polish.

The difference between a kolene treated and non kolene treated part is that the treated one might last longer if you run with low pressure. The clutches still die first, though. The other advantage would be the increased strength which would make it harder to damage the edges of the drive tangs on the steels. I doubt this is much of a concern for street cars though.
 
well your right on he Teflon seals. I replace them all the time in 6l80/90 gm transmissions for harsh delayed gear engagement. the wear out, I am an experienced builder, GM, but never a Chrysler transmission before. that is why I'm putting the feelers out there. this is my car, not a customers, I want to make sure all the goodie tricks/etc I can do while out and apart the better for me and my car. don't want to do it again, as it is I have to remove the a998/a999 lock up that is in there, because is does not engage gears till I rev it up. bought from a guy I knew that (claims also has shift kit) I think it has been done wrong, or something ripping it out, shafts WAY to early, also has a 5-1 ratio in it now/ the new trans A904 will be 4.2-1, built by me and my choices. want is to hold gears longer. and shift solid.
 
Hey all, I am new to the forum but have been slowly fine tuning my '73 318 dart with a 904. I read where AJ/FormS was writing about how you got it shifting pretty sweet even around corners with part throttle kickdown. I don't have that feature (the PTK) but I am going to install it on my 904 and wanted to pick your brain, if y'all don't mind too much!

First. I hear the PTK works at about 3/4 throttle, is this true? From AJ's note I think he got it down to less than that at low speeds (corners). Can this be done? How?
(I don't want to take apart the governor at this time but if that is the answer so be it.)

I don't know how the part throttle system really works, I know there is a spring in there. I understand this only works at below about 45-50 mph. Is there a way to raise the rpm window for the PTK up to about 60 mph?

I ask because if normal 3-2 kickdown is at full throttle, and ptk is a lt .75 throttle, that is still a lot of pedal in my eyes. How to bring this to half throttle or even 1/3 throttle? Possible?


Next question is, (unrelated) I could use the 2/3 shift (normal operation) a bit later than now, to match my 1/2 shift. I have heard of stiffer springs for 1/2 but not for 2/3. Do they exist? What size are they? (Dimensions)

Also have heard of "shimming" the spring with some washers. Any downsides to that that may damage the trans? (I'm talking lite shimming, not crazy 40 washers stacked up)

Abodiesonly rocks!

Anyway thanks in advance and hope to hear back from y'all!

-Frank
 
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