glhx said

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Haven’t taken out the front servo yet. I’m sure there is some black funk in there as this seems to be a place where the fluid doesn’t cycle as much. The back servo had very little of this though, so maybe this one won’t-

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The output shaft rides in this piece. There is a wear pattern on the aluminum. Is it worn out? I don’t know -

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This is a tail shaft bushing. It looks steel. It has some wear patterns and looks eaten up in some places -

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What the fluid looks like with friction material in it. This was in the bottom of the pan-

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Another of the tail shaft bushing-

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accumulator housing.....do these wear?

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This bolts to the back of the main transmission housing. It has wear patterns. There is a picture of it above as well. It’s all aluminum. Do these typically get replaced?-

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Main housing. That’s where the overrunning clutch goes. There are large needle bearings and springs. I’ve seen where people replace the springs and bearings but leave this part in there?-

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Valve body......black coating is friction material fluid that leaked out when I turned it upside down-

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Rear servo arm pin....housing. The pin that holds the servo goes here, there is a wear pattern -

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The pin had black film on it-

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Rear servo piston-

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This is the forward clutch drum before I took it apart. There is wear on the bushing.....but I don’t know if we replace these when they are like this or not. The clearance is shown between the clutch packs and the snap ring. I’ve heard this is measured with a feeler gauge. I need to know about this-

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This pin is for the rear servo arm. That o ring leaks and goes out the tail shaft seam. It’s rare the or ring leaks but I’ve heard when it does it’s hard to track down and the tail shaft has to come put.
You screw a bolt into the back of this pin to get it out. It slides right out and the tail shaft is what hold it in there-



That’s all I have for this. I have not taken apart the front pump yet so I don’t know what that looks like. I know the bushing that the converter rides on it eaten up but that was brim a cracked torque converter hub which is common with these 904 transmissions.

I could have just pulled the pump and put a new bushing in there and maybe gotten some Mike out of it. I figured the transmission was not far behind and I didn’t know what had ever been done to it.
I can say that it was painted ford blue so it has been out of the car.
I can’t say if it was even original to the car. It was out of a 318 76 charger.

I won’t be driving this car much. I don’t really drive the car hard at all and don’t need performance parts. Maybe a shift kit.

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glhx said

I just tore down this 904

I’d like to know what kit to buy or what separate parts are needed to refresh this or whatever it needs.

It had no problems shifting before I tore it down. I had recently changed the fluid. There was a lot of black powder in the pan when I pulled it to do the change....
So this time there was very little. It was probably run 50 miles since the change. I tore it down because the torque converter hub was cracked and tore up the bushing it rides on.
I figured if that was bad....what else was bad.

This is the first time I’ve ever taken apart and transmission. I have a general idea of how it works. Some of the forward clutches looks like they were pretty rough compared to what they should look like.

It looks like I was about to lose all my forward gears

I’ve got about 50 pictures I’m going to post of the wear on these parts.

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Reverse band.....I don’t even know what this is supposed to look like. Are there any upgrades for this. It doesn’t look as worn as the other band -

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Don’t know what this is. It has a thin bushing in it. Should I replace the bushing. It also looks like something sits or turns where it’s shiny -

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The reverse clutch packs didn’t have the gouges taken out of them like the forward clutch pack did. This one just has this one spot where it’s gray. That’s gouged in a small place but I’m sure it gets worse after they get beat up like that -

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Looks ok. Doesn’t mean it’s good. This is one of the reverse steels. How can you tell if these are good and can be kept. Or bad and need to be replaced?-

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A typical example of the reverse clutch. This one is intact -

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a picture of the output shaft,......-

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One of the reverse steels......the one has the wear marks on it. Those round line Pattern like it needs to be polished -

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Another reverse clutch pack. Looks a little worn....you can see where it has penetrated the surface and gotten a little rough in places -

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Looks like the reverse Simpson gear set. What are all the gouge marks from. All the rough texture inside there. The gears felt fine. They seem tight and don’t have a loose feel by hand to them. -

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A picture of the upper end of the output shaft. Those two polished parts ride on the copper color bushings that are pressed in to the clutch packs or other parts like them-

I left out pictures of the other steels and reverse clutch packs. They look the same as the ones above. No burn marks on them. Very little gouging or friction surface broken down.
The forward gears are nothing like this. Much worse.

All that black stuff I found in the pan before this trans fluid change was friction material.
I changed it because it was leaking badly. The seal on the area where the valve body comes out of the transmission to shift it......went bad. I had to pull the valve body to replace it. As I didn’t drive it much.....it didn’t have time to keep trashing the friction material. It would have with more miles and I would have had more in there until losing all forward gears. I just had a turbo 350 lose all forward gears like this. I’m guessing this is exactly what happened to it

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