Inspection of a 904 torqueflite

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glhx said:
You used round stock and the welder just filled in the base and built it out?

Did you drill all the way through 1/8 npt. My biggest problem was the angle on this and the plug just threaded all the way through the hole because it had nothing to seat against.

I was thinking maybe do a 1/4” diameter all the way through to the valve body......and then drill a size or two bigger for the plug....just not going very deep with it. Maybe 3/4” deep or less into the long drilled hole. so the plug would seat. Using a 1/8 pipe thread which has an outside diameter of closer to 1/2” (.40). It looks like that’s what you did and a&a did as well.

Your plug is sitting flush with the surface.

What would it take to trash the case to the point it’s ruined in this particular area?

I looked at 3/4 x 1” bar stock 6061 aluminum on eBay to start with, but I’m not around the transmission right now. Just looking at the pictures. The welder might even have this bar stock laying around and have an idea of what they want to do.
Click to expand...
Well judging from your terminology, you do understand that all pipe plugs are tapered. You cannot just drill all the way through with 1/8 pipe. No such thing. There is a specific tap drill size that you drill all the way through with and then you thread the hole with the 1/8 27 pipe tap to about half the taps length. I do not think you have ruined your case. The key to doing this job is to fit the bung to the case so there is very little gaps anywhere. This will make it easier for the welder. We kept damp rags around the pan rail to keep the heat down and avoid warpage.
As I said earlier, hand files are your friend. A welder/fabricator may be able to supply the aluminum and do the whole job for you.
Some people just buy the race prepped case from a and a that comes with the external adjustment and many other features already done. My threaded hole actually has to plugs in there one on top of the other because I went too deep with the tap. My bad.
My bung started as a piece of round bar stock. I then filed ground on a bench grinder one end of it to get the shape of the case.
When it is square and pretty well gapless on the case, have it welded on. Once welded I filed everything to get the pan rail smooth.
After that you have a flat surface to locate and drill a hole right through and then thread the hole.
 
With the accumulator and servos.

Do you re hone those if your putting new ring gaskets in them. Teflon or cast iron.

I have a new accumulator and a new rear servo with new rings. The front is original but I have new rings for it.

Also. Where I did thread that hole for the pipe thread. Not that it matters now, but I threaded that tap all the way through. Soits the biggest diameter it can be.


However.....I see what you mean by tapered. I saw some of this when looking at the design of pipe thread, but it was too late.
Now I have a good understanding of it and what you mean by going in halfway.
For this one....now that I know that. I’ll make the hole for the Allen wrench, smaller than the hole for the plug and go with a standard plug that has a seat. I can see myself stripping out a pipe thread in the aluminum with even a slightly smaller hole behind it. If the pipe thread had a shoulder on it and a stopping point. I would trust it a lot more, but I don’t want to have an external shoulder. I’d rather have it sit flush and inside the hole like yours is. I learned something here. A few things actually.

Messed it up but now it makes sense. I would not have thought of using bar stock. As much as that makes sense. I still wouldn’t have thought of it, so I appreciate that and the detail you explained it.

I’ll see tomorrow what I can do. I’m out of my skill level on this one, but I still think I’m going to try it.

I am working on two of these torqueflites at the same time.
I messed the other one up worse but I think it can be saved pretty easily with the modification the way you showed it.

I’ll post a picture of it for the heck of it. I’ve learned a lot so far about these and personally, I think transmissions are more difficult than engines. This is a pretty big crash course and one of the reasons I’m taking so long with it is the research.

The other day.....a member from here talked of mixing the 999 and the 904 output shafts and some of the components. I was going to use the 904 output shaft with 999 gear sets on it.

they looked similar and measured out the same. He might have just said mixing the 904 rear planet with the 999 sun gear.

He told me that he did that a few years back and the results were not ideal. Had I don’t this......I would have been walking home in short order.

I’m keeping all the original parts with all the original parts. I wouldn’t have otherwise.

The 904 output shaft has less play on it than the 999 sand there’s no real way to take the play out. So I’m just gonna live with it and it should be fine.

Either way.....I’ve come a long way since I started this.
 
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The problem with the play is the rear snap ring that holds the governor and parking gear on.

It’s allowing the ring gaskets to trash the output shaft support, or at least that’s the theory. It has .027 999 compared to the 904 which has .017 and had no wear on that support.

It was only the front ring and not the back ring of the two. The only way to get that play out that I could see was a thicker snap ring. Which is not available.....even from a&a

Or to find a shim that sits behind the parking gear or governor.

The only reason I was gonna let it go is because I’m not sure that it was even the cause and there is no specification on that movement.

And I can’t really tell for sure if that was the cause. I just thought it was excessive. Why the front ring diggin in and not the back. Who knows. Maybe it just got bound up and dug a hole and stayed there after the hole was started. It isn’t one of the interlocking ones.
It was a wide gap ring that put more pressure to seal better.

Crappy fluid could have caused it and just worn it down. In the rebuild I don’t think it was replaced.

I started looking at the parameters of how the lock up clutch engages in the different gears. The spark control computer has a lot to do with activation of that relay. It could have been moving the lock clutch in and out at the wrong times.

Trashed the transmission....
Then they had it rebuilt and didn’t fix the original problem so it started to trash it again. It would have made drivability terrible.

Since my
Lock up clutch is on a switch and won’t be used for anything except highway.....I don’t see a problem there.
It’s going to be set up on governor activated pressure switch at some point to make it adjustable and automatic.....but not like that spark computer. I want more control over it. That’s also just a theory. But as I saw nothing wrong with the inside of this trans. I don’t know what else it could be. The packs were perfect.
The steels weren’t burned at all. Something had to make that fluid black as it was and thin as it was.
 
48237776556_6518688669_z.jpg
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Welll......maybe it wasn’t .027
It was .023.....

But that’s still a lot.

That snap ring.....is .050
If I could find one .065

That would leave the play at around .012 and that would be a lot better.

I’m still looking into honing those bores to cut in the new sealing rings. One of the books says you can put a quick hone on it.
I might have left it alone but I have to get a new front servo. One of the kids took one of the front servos and thought it was really cool. Then completely denied it. They are 6 and 7. They probably lost it so I’m in for a new one or used one with new sealing rings

So I’m looking at
snap ring thickness
Honing servo bores
And adding bar stock for line pressure adjustment I’ll probably never need.

After that......I’m done and putting it back together.
 
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glhx said:
With the accumulator and servos.

Do you re hone those if your putting new ring gaskets in them. Teflon or cast iron.

I have a new accumulator and a new rear servo with new rings. The front is original but I have new rings for it.

Also. Where I did thread that hole for the pipe thread. Not that it matters now, but I threaded that tap all the way through. Soits the biggest diameter it can be.


However.....I see what you mean by tapered. I saw some of this when looking at the design of pipe thread, but it was too late.
Now I have a good understanding of it and what you mean by going in halfway.
For this one....now that I know that. I’ll make the hole for the Allen wrench, smaller than the hole for the plug and go with a standard plug that has a seat. I can see myself stripping out a pipe thread in the aluminum with even a slightly smaller hole behind it. If the pipe thread had a shoulder on it and a stopping point. I would trust it a lot more, but I don’t want to have an external shoulder. I’d rather have it sit flush and inside the hole like yours is. I learned something here. A few things actually.

Messed it up but now it makes sense. I would not have thought of using bar stock. As much as that makes sense. I still wouldn’t have thought of it, so I appreciate that and the detail you explained it.

I’ll see tomorrow what I can do. I’m out of my skill level on this one, but I still think I’m going to try it.

I am working on two of these torqueflites at the same time.
I messed the other one up worse but I think it can be saved pretty easily with the modification the way you showed it.

I’ll post a picture of it for the heck of it. I’ve learned a lot so far about these and personally, I think transmissions are more difficult than engines. This is a pretty big crash course and one of the reasons I’m taking so long with it is the research.

The other day.....a member from here talked of mixing the 999 and the 904 output shafts and some of the components. I was going to use the 904 output shaft with 999 gear sets on it.

they looked similar and measured out the same. He might have just said mixing the 904 rear planet with the 999 sun gear.

He told me that he did that a few years back and the results were not ideal. Had I don’t this......I would have been walking home in short order.

I’m keeping all the original parts with all the original parts. I wouldn’t have otherwise.

The 904 output shaft has less play on it than the 999 sand there’s no real way to take the play out. So I’m just gonna live with it and it should be fine.

Either way.....I’ve come a long way since I started this.
Click to expand...
The play you are talking about with the parking gear/governor assembly I do not believe that matters. If the sealing ring is falling out of the output support because of an extra .010 of play then something else is drastically wrong. If the output support is grooved then you need to replace the support.
The total output shaft end play will change when the trans is fully assembled.when you measure the input shaft end play the output shaft become part of the equation.
 
glhx said:
View attachment 1715388150
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Welll......maybe it wasn’t .027
It was .023.....

But that’s still a lot.

That snap ring.....is .050
If I could find one .065

That would leave the play at around .012 and that would be a lot better.

I’m still looking into honing those bores to cut in the new sealing rings. One of the books says you can put a quick hone on it.
I might have left it alone but I have to get a new front servo. One of the kids took one of the front servos and thought it was really cool. Then completely denied it. They are 6 and 7. They probably lost it so I’m in for a new one or used one with new ring gaskets.

So I’m looking at
snap ring thickness
Honing servo bores
And adding bar stock for line pressure adjustment I’ll probably never need.

After that......I’m done and putting it back together.
Click to expand...
I have never honed any of the servo bores and I ve never had a problem. I have gradually been switching over to Teflon sealing rings where applicable.
 
The 999 total play was amazing. It was around .030 and that’s with some slightly worn thrust washers. When it goes back together it should be in the 20s

That output shaft was definitely grooved on the front ring. The ring itself was still intact and was around the same as the reaction shaft rings in the way it was on the lands. The fronts going into the direct clutch were fine.

I have did get a replacement for the output shaft support. It’s used but is in excellent condition.

The 904 output shaft support showed very little wear at all.
I have some cast ring replacements but if you think Teflon will seal better. I’m not opposed to getting them for all the sealing rings.

The new accumulator and billet rear servo have them. The 1987 999 front servo came with them.

The 76 904......everything was cast.
 
If any of you have a front servo housing lying around...lol
I’m in the market for one due to 7 year old curiosity and theft.
 
Did you get the name "ring gasket" out of one of your books, or are you just making up your own names for parts; just to make this whole thing more interesting?
 
Lol.....I made that term up........like mopar made up the term......drive breakaway.

So I’m guessing you don’t have a servo for sale.
I don’t need to hone those bores and there is no kit to fix that play.
 
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Well it's just asking for confusion. You already have plenty of that l can tell. But it is a good example of what not to do when attempting your first rebuild. Two different people have already addressed the issue of tailshaft endplay, but l guess you missed that; being busy drilling holes in your case. The worst mistakes l see first timers make are to assume facts about their trans that are not verified. It all seems simple; that is until you take it for your first drive and it doesn't work correctly. Then we'll see some hilarious made up jargon..spiced with expletives that we're all too familiar with. You need to learn transmission terminology, and then proofread your post to make sure it makes sense. Then maybe more readers will take an interest and begin again to post helpful hints.
 
Any bore is to be treated just like an engine cylinder bore; if it needs honed then it needs a bigger piston PLUS bigger rings. Not available. I throw the stuff away. You should by now have found a nearby source for transmission parts. If you start shipping hard parts....it's too easy to end up with clusterjunk. Part in hand for part in hand. And even after you've learned the proper terminology (and make sure the person you're dealing with has as well), and every stage of these builds are simplified, there will probably still be errors. And that's why people hate working on automatics. An engine you can throw together and it will probably at least run, but a transmission is unforgiving; one little mistake and you can feel it.
 
Dropped off the case at the welder today. Should be able to fix the case no problem. He’s gonna build it up with round stock and the machine shop guy next door will machine it out so there will still be line adjustment.

I should have just went with a 42rh. Same 2.74 gear ratio and a better set up for what I’m doing with it. I didn’t know at the time I started all of this that you could put one of those in an a body and they are close to the same transmission. Would have cost the same if I had left The transmission stock.

The 999 will do in this case. I still have the original 76 904 and another 318 sitting around. The 904 is getting rebuilt right next to the 999 and none of the parts will be mixed up.

I have no idea what I’m going to do with the 904 except put all new parts in it that I bought with the other parts. Then put one of those Transgo Tfsc kits in there to give it a new manual valve and put the springs in to take care of the other upgrades that kit provides.
 
Yes you should go get an overdrive and just use whatever parts you already have in that one. Why mess around with this three speed stuff when you really want an overdrive and a lower first gear? Your new lockup converter will work in the A500.
 
In working on putting this back together. I was able to put a used but good output shaft support back in. It didn’t go in as smooth as the old one. I had to tap it in with a rubber mallet.

On the output shaft itself. I installed 2 new locking style ring seals. Greased them down with transmission lube paste. They will not compress down into the output shaft support.

I took one of the seals off and put it down into the support by itself. It shows 0.005 clearance.

Is there a special tool or technique to get these back in?
Should I file them some to get a little more clearance?
 
glhx said:
In working on putting this back together. I was able to put a used but good output shaft support back in. It didn’t go in as smooth as the old one. I had to tap it in with a rubber mallet.

On the output shaft itself. I installed 2 new locking style ring seals. Greased them down with transmission lube paste. They will not compress down into the output shaft support.

I took one of the seals off and put it down into the support by itself. It shows 0.005 clearance.

Is there a special tool or technique to get these back in?
Should I file them some to get a little more clearance?
Click to expand...
What do you mean by it had .005 thou clearance.
You said the rings were locking style. I assume you mean that you put the sealing rings on the parking gear that slides into the output shaft support. Locking style sealing rings should be self adjusting.
Where are you measuring the .005 clearance?
 
Duane said:
What do you mean by it had .005 thou clearance.
You said the rings were locking style. I assume you mean that you put the sealing rings on the parking gear that slides into the output shaft support. Locking style sealing rings should be self adjusting.
Where are you measuring the .005 clearance?
Click to expand...

48891303208_2e672ced66_z.jpg
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It was a little crooked when I measured it. The actual clearance is .018 .....I was measuring the gap you see here to make sure it was the right ring. Pretty sure it is.
It was tight to even get it in there like that. The edges are sharp that they just catch.

When that ring is on the output shaft. It definitely doesn’t want to go in. I’ve put some pressure on it and turned it.

I did replace the output shaft support. The part number is the same.
I can’t even get the first ring into the support. They don’t want to compress to go in. Wi5 the trans on the floor and my full weight on it. Trying to wobble it back and forth. It still would not go in.

Given I don’t have a baseline for what this is supposed to be like with new rings. I can’t say if this is normal or not
 
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Stop putting your full weight on your transmission; and stop beating it with a hammer. Are you trying to kill it? You wouldn't do that to a patient would you? The weight of the shaft plus governor is enough for it to drop in. Gently tap the ring, sealing ring, interlocking ring, seal, (whatever you choose to call it today) into the groove.
 
glhx said:
View attachment 1715407785 -
Won’t compress

View attachment 1715407784
Click to expand...
Looking at this pic some more, it looks like a Teflon seal ring.
You may have to pack the ring groove with assembly grease to get the ring to stay contracted in the groove. I have heard that Teflon rings can be difficult to assemble with Teflon rings. You may need to pack them with grease and squeeze the ring down into the groove with your fingers to make sure it is not protruding anywhere. Then it should slip into the bore easier.
 
After some time and trial. I was able to get the rings to compress. Once they did it was easier to get the output shaft in and out as needed. They are the interlocking set. It just took some more wiggling to get them to compress

Once the output shaft was in. I kept adding the pieces. I had replaced all the bushings with my press and a bushing driver set. They went in smooth.

When trying to put on the sun shell with gears. It wouldn’t lock into place all the way. It was 1/16” off.... I couldn’t figure out why. There was no reason for it not to.
I found out one of the bushings was tight. It wouldn’t let the shell slide into place. I took it all apart and put the sun gears on the output shaft by itself. Just to make sure there wasn’t any other binding.
There are two bushings in the shell. I filed them and finally was able to get it to seat. Ruinin*the bushings in the process.

Is this common where you press bushings in and they have a sort of high spot and won’t work?

So then.....I decided to check the others. I found the reaction shaft had the same issue. It was tight and wouldn’t let the pump set down into the input shaft.

So.....I’m building two transmissions. 999 and 904. Same transmission basically. The 904......no issues. Those bushings are the same and were pressed at the same time. Same part number even.
The 999 has some of the bushings tight. What causes this? They were pressed in gently and went in fine. Now. I have to order another set. Replacing all the bushings has been a learning experience and not always gone smoothly.
 
the output shaft support was tapped in. It wouldn’t go in by just dropping in. I read in toms book that some of them have to be gently tapped. I did that and torqued it down.
 
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