This is for you guys that know and understand transmissions...
Last December, after we got his newly acquired '74 Dart Sport to fire up, my son jumped inside, put it in drive, and took a spin around the back yard. We know it goes forward. But, the car had been sitting for quite some time and was not getting oil up to the rocker arms. So we turned it off and decided to rebuild the engine. That's the last time it moved under its own power. Since then, we have pulled everything out of the engine bay so we can paint it. We removed the transmission as well.

Here's the question. Before spending any money on taking the 904 to a transmission shop to check it out and service it, like we planned on doing, are there some basic things we can do ourselves? I wanted this project to be a learning experience for my son (and myself), so he knows how his car functions and what it takes to maintain and repair. Is this something we should try to tackle, or is it best left to the professionals? What could we do to minimize the cost if we still want to take it to a shop for a professional inspection? Obviously, having the transmission out of the car is going to save in labor already. I'm not afraid of jumping in with both feet to save some $$$$, but I also want a safe and reliable first car for my son.

Give me your honest opinion,
Jerry

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There's a difference between ignorance and stupidity.
Ignorance is not knowing any better.
Stupidity is knowing, yet doing it anyway.

To "freshen-up" a working 904 is not all that hard, you will need a Factory Service Manual.

I would get a shift kit for it, I like the Trans-Go kits.

Use the shift kit's instructions to pull-out the valve body.
Use the FSM to do a "pressure port air check", this will show you where there may-be seal problems.

Pull-out the front pump, it is a goo idea to get a shop to put a new bushing and front seal into that.

Pull the clutch packs and take a look, I always put new friction discs in the forward clutch (these get a lot of use) and tend to leave the reverse drum friction alone. (these get little wear) The bands should be fine.

I would stop with just refreshing the friction parts, basically you go about 1/2 way into the gearbox, leave all the rear planetary stuff "as is" unless you really want an HD gearbox. (you go in deeper if you want the low first gear option or 4 pinion planetary sets)
DD

Doc,
What are "shift kits" and what are they for?

_________________
There's a difference between ignorance and stupidity.
Ignorance is not knowing any better.
Stupidity is knowing, yet doing it anyway.

I posted a few tips I've learned over on .com for ya.

Wow, there is more to this question then I have time for, I need to get back to you on this one.
Lets just say that a shift kit makes a Torqueflite work "more better".
A good "bang for the buck". (and a good bang of a gear!)
DD

Thought I'd bring this back up to the top here...

Are there any special tools you need to freshen up a 904?

Also, is it easier to pull the tranny while leaving the engine in place or to just pull the whole schmear? I've got access to a hoist so pulling the whole schmear wouldn't be too bad.

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'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

Jopapa,
Thanks for bumping this to the top, I had forgotten about itl. I would still like for someone to explain the "shift kit" thing to me.

Jerry

_________________
There's a difference between ignorance and stupidity.
Ignorance is not knowing any better.
Stupidity is knowing, yet doing it anyway.

The shift kit I think I can explain well enough. It basically modifies the valve body and involves putting stiffer springs into the transmission itself, which results in much quicker (but harder feeling) shifts. Better for racing since less time is spent "between" gears and less power is lost, and also because of the reduced shifting time, the tranny lasts longer between overhauls.

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'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

The shift kit is a set of parts that is meant to 'reprogram' your automatic transmission to give different results depending on your desire. Most firm up the shifting from gear to gear (good for better mileage if yours is soft shifting and delaying between shift), some contain a new valve body plate,springs, and check balls, to help determine a better rpm range to shift at (street rpms, drag range, RV/Towing...). There's much more to this, but that's pretty basic. There are things you can do without a shift kit, that can help your torqueflite out a bit...check for old articles in Mopar Action, and other Mopar literature sources...

-D.Idiot

Thanks guys,
Once we get the Sport put back together and running, I'll take time to research this more to see if it's something we might want to look at for future mods.

Jerry

_________________
There's a difference between ignorance and stupidity.
Ignorance is not knowing any better.
Stupidity is knowing, yet doing it anyway.

Couple of little things to add to the explanation of shift kits:

When an automatic shifts, my understanding is that it is actually in both gears at the same time while going from one to another. Since the output shaft obviously cannot spin at two different speeds at the same time, there is slippage. A shift kit speeds the shift up, thus reducing the amount of time that the slippage occurs. This reduces wear. The other thing shift kits do is they generally increase line pressure to clutch packs and band apply pistons. This increases the amount of torque it would take from the engine to cause the transmission to slip. So, you could say that the increased line pressure increases "holding power".

I may be off on some of what I said-if so, please feel free to correct me.