Hi again, Slant Sixers!

As promised in my Ford 8.8 thread, this is the thread on the transmission that will be connected up to it.

Recently, I destroyed my 3rd gear, in what I imagine was the original A904 with roughly 78K miles on it in my 1972 Plymouth Duster. I think not using a kickdown cable and having a (ironically, NEW) leaky transmission pan gasket with my shiny new high-capacity pan/filter extension is what ultimately fried it.

Why no kickdown? I got ahead of myself and installed a set of headers and intake/4-barrel carb based on the advice of the previous owner with a 70's big block Charger: "Oh, you don't need one of those, just shift it manually and it will be fine!" lol... I did not have a manual valvebody in my stock slant six-powered Duster.

So, now that you know my plight and ignorance, you now know why I'm on here.

I REALLY wanted to do a LA VA-based A904 from a heavy duty truck with low mileage, even went so far as to put down a $100 deposit which I may never see back, however as I learned AFTER the fact, the cases are simply too different and won't bolt-up.

So now I'm on Plan B, which involves a full performance rebuild.

My question is: Are the Forward and Direct drums inside the TF6 the same as the TF8? I want to increase the number of clutches in either or both drums. I hear that on the TF8 A904 some racers are actually able to stick up to 5 clutches in there when using Alto reds and either A.) grinding-down the flexplate 0.02" at some spot (if you guys know exactly where, that would be great!), or B.) using a thinner snap ring(s).

My source for the clutch pack "conversion" can be found here: http://www.forabodiesonly.com/mopar/thr ... ost-580516

In addition to this, I already have a Performance Transmission rebuilt kit that comes with 4 Forward drum red clutches, a custom performance rebuild 2,500 stall converter, ATI forward pattern semi-auto valvebody, and (finally) a Lockar kickdown cable.

Also, if anybody knows on what other parts I should watch-out for, such as solenoids, Kevlar bands, kickdown levers, etc., etc. that I may want to swap-out while I'm in there to ensure I have a perfectly streetable transmission that will take 300-500hp of abuse regularly (I have a problem with my right foot), I would love to hear your thoughts.

As I posted in my other thread, this is attaching to a tweaked bigger-valve 225 slanty and a Ford Explorer 8.8 rear with 3.73 Tru Trac.

_________________
1972 Plymouth Duster:
- 225ci
- Offy 4-Barrel Intake
- Weber 38/38 DGES
- Clifford headers
- Split 2.25" dual exhaust
- Pertronix digital ignition conversion
- Black-out custom digital gauges
- Front disc brake conversion
- Viper Blue

I am not positive, but I think you can swap everything internal from the V-8 trans into the six cyl case. The only problem might be the first/reverse band, if the V-8 has the double wrap band, with an anchor in the case. The slant six case probably does not have the anchor.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Thank you for your input, Charrlie!

I think you are right about that. I was literally just reading the allpar article on the transmission and found this:

"The 904 uses two different types of low-reverse bands. One type is called a double wrap band, similar to the Hemi kickdown band; it is used with the V8 engines to give greater low-reverse drum holding capability. The other band is a single width band that has less torque holding capacity and is used with six-cylinder engines. The 727’s single width low-reverse band and is used with all engines."
http://www.allpar.com/mopar/transmissio ... -hand.html

I'm also waiting to hear back from A&A Transmissions, and already had some input from SMR Motorsports on potentially needing to get higher-clutch-specific drums/shaft, and a 4-pinion planetary.

I was kind of hoping A&A could get back to me with some similar parts, since I'm sure shipping to Texas is more from Canada than it would be from Indiana, not to mention that they have individual clutches and such I could get from them without much hassle.

Thoughts?

_________________
1972 Plymouth Duster:
- 225ci
- Offy 4-Barrel Intake
- Weber 38/38 DGES
- Clifford headers
- Split 2.25" dual exhaust
- Pertronix digital ignition conversion
- Black-out custom digital gauges
- Front disc brake conversion
- Viper Blue

Alright, as an update since I created this thread, I'm now out about $380. lol

In the last few hours I ordered:
- 4-pinion front planetary w/ ring gear
- 4-clutch front drum w/27-spline input shaft (non-locking)
- 5-clutch direct drum (non-locking)
- Alto red .061" Forward friction clutches
- .068" Kolene steels
- .062" 727 Snap Ring
- Kevlar-lined single-band low/reverse band (1.375")
- Kevlar-lined intermediate band
- Billet aluminum low/reverse servo kit

I need to go home and check what sort of kickdown band I have in the performance rebuild kit, but I can always snag the 1.6" Raybestos front band if that's not what I have already.

... I am REALLY hoping the snap ring is the right size for my 904, but figured at least that much might be interchangeable and give me the clearance to cram an extra friction disc into my Forward drum... if not, does anybody have an idea on where to get one (like NAPA?) or if I should just stop over-thinking it and grind-down my flex plate that tiny .020" to give me the clearance that I need?

Also, does anybody know just how interchangeable the forward pinion gears are? I ordered what looks like a very good condition aluminum one, however the splines won't match. Is there something I can do to still make it work or do I go back and start over with that one? Am I going to need a larger sun gear? I think the thing came out of a 1963-1966 car and just want to swap it in for my 3-pinion unit.

Anything you guys think I may be missing? I figure a gasket or two here or there won't be an issue, but what other parts would you recommend swapping in order to make this thing reliable on the street with some strip work down the line?

Thank you all in advance!

_________________
1972 Plymouth Duster:
- 225ci
- Offy 4-Barrel Intake
- Weber 38/38 DGES
- Clifford headers
- Split 2.25" dual exhaust
- Pertronix digital ignition conversion
- Black-out custom digital gauges
- Front disc brake conversion
- Viper Blue

Welcome on the board. Others are answering your transmission-guts questions, but I want to address this:
You can do a lot better than that with the pan and gasket described in this post.

See this thread for kickdown options.
No solenoids in any but the last '86-'87 Slant-6 truck/van Torqueflites with electrically-operated lockup torque converter.

Fluid: use Dexron-VI. It is an excellent fluid in every respect, better than ATF+4, FAR better than Type F, and at least equal to the costly boutique special-brand fluids.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

You need to be carefull mixing and matching different year parts. That is why I suggested swapping everthing from one trans to the other. I do know, there is a difference in the spline count, on the front end of the output shaft ( I think it changed between 1967 and 1968), and you need the corresponding plantery gear set.

There are also differences, in the lip seals and seal rings, between years.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

I've got it fixed now with a new gasket... the one that came in my kit was apparently defective. Lokar kickdown cable was installed also. Dry as a bone and full of fluid now... too bad that the dang thing lost 3rd gear and now has to be rebuilt. :X

Yeah, I really meant "servo" in my original post... I get servos and solenoids confused sometimes.

Have been using nothing but Dexron-VI for a couple years.

Thank you for your input, Dan. I actually learned a lot from you over the last couple of years.

_________________
1972 Plymouth Duster:
- 225ci
- Offy 4-Barrel Intake
- Weber 38/38 DGES
- Clifford headers
- Split 2.25" dual exhaust
- Pertronix digital ignition conversion
- Black-out custom digital gauges
- Front disc brake conversion
- Viper Blue

Looking at the design it kind of looks like the inner thing with the splines might actually come out and swap with the correct inner piece, but I'm new to all of this, so I guess all I can do is wait and see... I just saw "aluminum" and got really excited. I know the steel piece is about 2x as strong, but the 4-pinion aluminum is apparently good for performance and still strong enough to be run hard by 600+ cars for several drag seasons. I guess I'll know once the thing gets here and I get to tinker with it. In worst case scenario I might just pick-up another steel set of for $50-100 more.

Oh, if only that truck 904 would have worked in my car. The guy wanted $175 for a fully-working unit with around 15K miles... wish he answered me and told me it was behind a V8 before I wasted 2 hours driving there and back on the "hope" it would be behind a slant.

_________________
1972 Plymouth Duster:
- 225ci
- Offy 4-Barrel Intake
- Weber 38/38 DGES
- Clifford headers
- Split 2.25" dual exhaust
- Pertronix digital ignition conversion
- Black-out custom digital gauges
- Front disc brake conversion
- Viper Blue

O.K., the anticipation is killing me, and now I'm positive the center piece does not come out (not sure why I thought that originally, either)... what are you racers doing about your front planetaries? Are you upgrading to 4-pinion? Do you know which transmissions I can get them out of or where to source them? I have a feeling I may be wasting my time with the part I ordered... nothing about the ratio, years, or spline count seems to add-up.

Am I over-thinking this? Do I just need a proper sun gear and shell to complete my setup regardless of year as long as it's a 904?

_________________
1972 Plymouth Duster:
- 225ci
- Offy 4-Barrel Intake
- Weber 38/38 DGES
- Clifford headers
- Split 2.25" dual exhaust
- Pertronix digital ignition conversion
- Black-out custom digital gauges
- Front disc brake conversion
- Viper Blue

Yes.

The Chrysler 904 is a well designed & strong transmission.
You do not need to do much more the a standard rebuild (using quality parts) to have a 904 that gives you good reliable service.

The things I tend to do to any "race" 904's I build:
-Up-grade to the 4 clutch pack forward drum.
-Use the wider V 8 kick-down band.
-Deburr, drill-out or drill extra oil return holes to get ATF out & away from the friction surfaces & front pump seal.
-Reduce or remove any "load control" feature from the kick-down band servo.
-Install a "shift kit" & a deep oil pan, with the filter extender.

Rebuild "mechanics" aside... the real effort is setting / fine-tuning" the pressure setting so the trans shifts when you want it to... with a shift that is firm but not harsh.
DD

Thank you! That's the kind of stuff I'm really looking for.

I will most certainly invade the shop area and address the oil return issue after doing some more research on these forums (I'm sure this is not the first time you have suggested this, so I'm going to find all the info out there ).

Something to keep in mind is that I'm really just trying to build this thing once (getting a stronger higher-stall torque converter if needed above 2,500 at some point later) to hold up to my ultimate 400-450rwhp (with turbo + EFI) goal without anything critical snapping and killing the rest of the trany.

I did check, and apparently my rebuild kit has the wider 1.61" Raybestos Pro kickdown band in the kit, so I'm really glad I did not throw more money at what I thought was a problem yesterday before even looking at it lol.

I'm going to be using an ATI pre-assembled forward pattern semi-auto valvebody, and definitely have the larger capacity trany pan already on the old trany.

I have the 4-clutch drum on the way also, however I also ordered a bunch of extra-thin "High Energy" Alto red clutches and a really thin snap ring (which I may still play around with to find the exact size needed) to see if it really is possible to stick a 5th clutch into my forward drum... I hear some V8 guys run 1,000+ hp in cars with this mod, then again, I may need to get an extra 0.020" by grinding down the flexplate in some spot.

The planetary thing is the thing I'm kind of hung-up on, but the more I read, the more it sounds like the one I ordered 'may' actually work... if not, I may be able to get away with some new shafts, gears, and or shell, and I will have all I need to have a really reliable unit that could hold 500+ hp all day every day.

Why is this a big deal to me? I am ROUGH on my cars. I have a '94 Acura NSX with reinforced shorter gears and a race clutch for daily-driving and keeping me happy for the last 7 abusive years, while the "gloriously German engineered" 700hp (with some mods/tune) CL65 AMG I find new ways to break monthly every time it gets out of the shop . I know myself. If I don't spend the money up front on something strong, I'm going to end-up repairing it 2-3 times more later... especially when adding power to low-horsepower cars. For example, I bought a lightly-used '08 Mitsubishi Evolution X a few years back thinking, "oh, this thing is faasst as-is, I'm going to just keep it stock for a while!"... then maybe 3 months later I have every imaginable bolt-on, converted to e85, and instead of the stock 223-ish awhp, it put down a "conservative" 372 awhp (down from the 401 we had it tuned to at first, specifically to keep stuff from breaking), and needless to say I fried my rear differential... yay convincing the dealer to replace it under warranty! Where is my 1972 Plymouth Duster warranty? lol

P.S. The '94 NSX replaced the '08 Evo after an ironic accident in which I was following the speed limit for ONCE in my life (40mph) and having some dodo t-bone me running the middle of a red light doing 50+mph from a small side-street... you can't make this stuff up.

P.P.S The 1972 Slanty Plymouth I had originally bought to replace the 700hp Benz to be a more reliable AND fun daily driver... I'm punting that Benz on to somebody else once everything is finally fixed on that thing, and using less than half the regular 3-figure repair bill money on "super car-ing" this thing.

_________________
1972 Plymouth Duster:
- 225ci
- Offy 4-Barrel Intake
- Weber 38/38 DGES
- Clifford headers
- Split 2.25" dual exhaust
- Pertronix digital ignition conversion
- Black-out custom digital gauges
- Front disc brake conversion
- Viper Blue

Just as yet another update, I feel like I may finally be done buying transmission parts.

Based on the advice of some V8 guys from another site, I ordered a custom billet 24-spring Front Drum Return Module (to replace the single wound spring), an intermediate servo spacer kit, and a billet front servo piston (already got the back one).

Front planetary aside, I think this thing may be good for 600 hp now... for my current 140-170 hp Slant build . It's OK, though. 250-300 hp is right around the corner, and I'm sure 400-450hp can't be too far away once I find a good machine/fabrication shop in the area to do a turbo and get everything else installed. Better safe than sorry! Total price of all parts for the transmission so far is around $800 with the 2500 stall converter and valve body, with another $800-$1,000 in installation. Kinda pricey, I suppose, but seems like a great deal for a high-horsepower race transmission that does not waste a lot of the lack-luster power between the engine and the pavement. I'm positive some of you can do it much cheaper, like if you found a truck 904 and spent the time gutting it yourself to get all of the parts I had to buy separate due to a lack of free time and place to work on a 90 lb transmission.

_________________
1972 Plymouth Duster:
- 225ci
- Offy 4-Barrel Intake
- Weber 38/38 DGES
- Clifford headers
- Split 2.25" dual exhaust
- Pertronix digital ignition conversion
- Black-out custom digital gauges
- Front disc brake conversion
- Viper Blue

That 2500 converter, is that stall for a slant six or a V-8? If those are V-8 numbers, you will be very disapointed. It will stall about 500 rpm or more less. For most slant sixers, they start at 2500 rpm actual, and go up from there. Myself, mine stalls at about 4,000 rpm with my 225, and about 3200 rpm, with my 170.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

I asked, and they confirmed that it was a stock unit modified for higher-than-stock stall.

I believe the bone stock one is rated for about 1,700-2,000, while this one is rated for 2,200-2,500, so about 500rpm higher-than-stock stall, depending on application, I guess. I'm expecting about 2,200 stall now, and maybe 2,300 or-so stall once I add some more NA power with valves and cam.

It was dirt cheap ($185), seems to be on-par with TCI in build quality, and I definitely intend to go with a smaller-diameter custom built one with a balloon plate and all once I go turbo. Figured I could at least save a little cash for now, and then have one made to my cam, gear ratio, etc specs later.

Just really did not want to break my 7.25" rear until I have a chance to swap-in my Ford 8.8," and figured the higher stall won't be too useful for me until I get above the 140-170hp I'm at now. Worst-case scenario, I won't be using an original 1972 time-bomb behind a newly-build race transmission. Safety first . Just going to be a fun daily-driver econo car for a few months until I get my house remodeled and sold... oh, too many projects.

_________________
1972 Plymouth Duster:
- 225ci
- Offy 4-Barrel Intake
- Weber 38/38 DGES
- Clifford headers
- Split 2.25" dual exhaust
- Pertronix digital ignition conversion
- Black-out custom digital gauges
- Front disc brake conversion
- Viper Blue

Doctor Dodge, I really want to thank you for your help so far, however would you mind elaborating on these 2 points? I did some searching, but not 100% certain on what you mean with this.

Where are these oil return holes? Drums? Valve body?

I ordered these 2 things recently:
https://www.transmissioncenter.com/shop ... 70-sonnax/
and
https://www.transmissioncenter.com/shop ... rn-module/

Will this help with the "load control" issue you are referring to, or is that something else?

_________________
1972 Plymouth Duster:
- 225ci
- Offy 4-Barrel Intake
- Weber 38/38 DGES
- Clifford headers
- Split 2.25" dual exhaust
- Pertronix digital ignition conversion
- Black-out custom digital gauges
- Front disc brake conversion
- Viper Blue