help needed with 904

-
What I find funny is if this was a motor the guru's would be coming out of the woodwork. Automatic transmission= tweet-tweet-tweet.....
 
j par said:
Thank you for your response and at this point Thank you for any response! With this supposedly have been built by a speed shop I'm assuming and at least a small shift is already in it and if not some of them upgraded Parts like you were talking about. big problem how does someone like me and you have no idea what's going on? Maybe all this stuff has already been done? And possibly a big waste of my time and money if it has...
Click to expand...
I think at this point you have 2 choices.
  1. Throw it in and see how it responds. Usually, the first thing that happens to them is it will start to shift extremely slow from 1st to 2nd.
  2. Spend a little green, take it to somebody that KNOWS mopars, and have them build it to what you want. Man, I've seen these behind some heavy horsepower and they hold up. 70Aaarcuda has them behind all 3 of his 10 second cars. Tony does them himself. He could tell you the exact upgrades needed. This may run you 650 bucks, but it would be the best insurance and peace of mind you would have. If you wanted, then you could get the right converter to go behind your stroker, and then you'd just have a quick afternoon swap from stroker to 318 if you stayed with the automatic
Sorry friend, I have no more to offer on the internals of a tranny. Maybe someday I'll take an interest in them and do them myself. But it hasn't been for over 30 years :)
Whatever you decide, good luck.
 
I appreciate your help 318willrun ! Given it's history of being built by a speed shop and only street used for two years with 318 in front and 7 1/4 out back and lost reverse possibly do to bad 1966 stock linkage? Of course Tony is already offered Help and likely it's on its way in the form of some paperwork. I try not to bug him too much because like you said he's got three cars in the 10-second range and that must keep him plenty busy enough. without a crackpot like me asking to many stupid questions. I'm just grateful for the help that he does give me. It was someone like himself that I was thinking that might be able to look at the pictures tell by maybe some of the numbers or configurations that it has been modified or not? Option number 2 is not an option with a budget build LOL. I do have the other transmission that I could try also if I need to.
 
The front drum seal could be bad and still have 3rd gear but not for long that could be y u have no reverse. Or a bad servo/ seal , lining came off of the rear band etc. Everyone builds a motor and puts how much coin into it. But a tranny is only worth a few dollars with almost zero importance. Of course the rear needs to be a Dana or 8.75. Kim
 
Is there any picture angle I'm missing so someone could tell if something ain't right ?
I put good money towards my four speed no regrets there. I'm just experimenting with this automatic transmission and pretty much hoping for the best but again if anybody sees anything I can remedy quickly before I give her the good old College try it would be cool. I blew up the 489 case 8 3/4 and now have a spooled 35 spline dana 60.
thank you for your response !

oldkimmer said:
The front drum seal could be bad and still have 3rd gear but not for long that could be y u have no reverse. Or a bad servo/ seal , lining came off of the rear band etc. Everyone builds a motor and puts how much coin into it. But a tranny is only worth a few dollars with almost zero importance. Of course the rear needs to be a Dana or 8.75. Kim
Click to expand...
 
only expert experance i have with auto transmissions is how to swap one out and how to burn one up! ive looked threw lotta old threads on here bout auto's but less ya know what thay talking about ya dont know what thay talking bout, ant just 904s it seems to me theres a huge void of info on auto trans re build and high performance mods even harder to find...why im following this thread, trying to learn what i dont know...
 
Me and you both...
this is not rocket science, I'm sure?
Likely just takes more time.


318willrun said:
I think at this point you have 2 choices.
  1. Throw it in and see how it responds. Usually, the first thing that happens to them is it will start to shift extremely slow from 1st to 2nd.
  2. Spend a little green, take it to somebody that KNOWS mopars, and have them build it to what you want. Man, I've seen these behind some heavy horsepower and they hold up. 70Aaarcuda has them behind all 3 of his 10 second cars. Tony does them himself. He could tell you the exact upgrades needed. This may run you 650 bucks, but it would be the best insurance and peace of mind you would have. If you wanted, then you could get the right converter to go behind your stroker, and then you'd just have a quick afternoon swap from stroker to 318 if you stayed with the automatic
Sorry friend, I have no more to offer on the internals of a tranny. Maybe someday I'll take an interest in them and do them myself. But it hasn't been for over 30 years :)
Whatever you decide, good luck.
Click to expand...
dirty white boy said:
only expert experance i have with auto transmissions is how to swap one out and how to burn one up! ive looked threw lotta old threads on here bout auto's but less ya know what thay talking about ya dont know what thay talking bout, ant just 904s it seems to me theres a huge void of info on auto trans re build and high performance mods even harder to find...why im following this thread, trying to learn what i dont know...
Click to expand...
 
Ya it's time to cut through the bull !!


dirty white boy said:
only expert experance i have with auto transmissions is how to swap one out and how to burn one up! ive looked threw lotta old threads on here bout auto's but less ya know what thay talking about ya dont know what thay talking bout, ant just 904s it seems to me theres a huge void of info on auto trans re build and high performance mods even harder to find...why im following this thread, trying to learn what i dont know...
Click to expand...
 
I do have this :thumbsup:
20170425_171110.jpg
 
Hard to tell if a valvebody has been modified since it is done internally. As far as the condition...you need to remove the valve body ....then you can air test the servos and the clutch pacs.....

the 904 vent is that top hole....so if you roll it around tranny it will leak out...otherwise it does not....lol
 
Well there it is? Crap! I need to get my slippers on and get out to the garage hold on I'm supposed to order dinner wait a minute did I feed the dog yet rats I'm glad I remembered that wait a minute do I have the little rubber tip to put in there it's upside down on the bench hold on a second I'm losing my mind here I need a little bit great information
 
Okay that information woke me up out of my nap. I'll get a fresh start tomorrow morning and start taking the valve body off. Is there anything I should know about how to take the valve body off? Anything I should not do anything I should do? I don't know what I'm doing! I swear I put a B&M shift kit in my72 Duster like 15 years ago.
 
I hope you get this figured out, I need to check a 904 for my next build, I have been running 4-speeds for the last 30 years, but this next one I plan on running an auto.
So I am in newbie territory also.
 
It's funny until I know something about this damn thing I don't know anything about it LOL. For all I know it could be in perfect running order but the part that's killing me is that I have it all out. I don't want to fix it after I put it in if there's anything to fix? LOL


sireland67 said:
I hope you get this figured out, I need to check a 904 for my next build, I have been running 4-speeds for the last 30 years, but this next one I plan on running an auto.
So I am in newbie territory also.
Click to expand...
 
But it's truly cool some of the tests here that 70aarcuda is posting up for me/us to try that's going to help...
 
Number two has clutch material bits in it, so on that ONE single point I would go with the other trans.
Looks like both have a double wrap rear band (holds better than the single).
You can air test the reverse servo to make sure it applies solidly using the fluid port next to the accumulator if you pull the valve body off.
It looks like both also have a possibly functioning TP lever, but you don't know for sure by that.
I can tell you that most shift kits worth their salt have a replacement separator plate between the two aluminum halves of the valve body that is a different color (like gold) and do not have numbers cut in them like both of yours.
Problem is, a lot of the shift kits direct you to drill out the plate instead of replacing it, so you can't really tell by that either unless you split the valve body and measure the corresponding holes to see if they are stock or have been drilled.
Also the shift kits sometimes have a colored pressure regulator spring and stock is plain metal colored.
No biggie, you can do it.

Here's the air check ports for each clutch and band apply to test it.
Hit any other ports than the red ones may result in fluid in the face. :D

I see AAR posted some of this already, but hope it helps.

autotrans-pressure-testports.jpg
 
First - thank you all good stuff!
Same question, air pressure amount?
Also I was wondering if I need to get any gaskets other than the pan gasket if I take the valve body apart which I'll probably want to do anyways if it doesn't have a shift kit?


TrailBeast said:
Number two has clutch material bits in it, so on that ONE single point I would go with the other trans.
Looks like both have a double wrap rear band (holds better than the single).
You can air test the reverse servo to make sure it applies solidly using the fluid port next to the accumulator if you pull the valve body off.
It looks like both also have a possibly functioning TP lever, but you don't know for sure by that.
I can tell you that most shift kits worth their salt have a replacement separator plate between the two aluminum halves of the valve body that is a different color (like gold) and do not have numbers cut in them like both of yours.
Problem is, a lot of the shift kits direct you to drill out the plate instead of replacing it, so you can't really tell by that either unless you split the valve body and measure the corresponding holes to see if they are stock or have been drilled.
Also the shift kits sometimes have a colored pressure regulator spring and stock is plain metal colored.
No biggie, you can do it.

Here's the air check ports for each clutch and band apply to test it.
Hit any other ports than the red ones may result in fluid in the face. :D

I see AAR posted some of this already, but hope it helps.

View attachment 1715042087
Click to expand...
 
This is where the PR spring is, and I see that valve body has a yellow spring.
That may be a kit indication, because I think stock is plain steel and not colored.

20170425_131406.jpg
 
j par said:
First - thank you all good stuff!
Same question, air pressure amount?
Also I was wondering if I need to get any gaskets other than the pan gasket if I take the valve body apart which I'll probably want to do anyways if it doesn't have a shift kit?
Click to expand...

Both seals for the valve body linkage would be best done now, as they are a PIA in the car.
The cork gasket on the trans bottom back by the mount pad is easy out of the car but a pain in it also. (under the metal plate with the Phillips screws holding it on)
This is the access hole for releasing the tail housing from the output shaft bearing.
There are no other gaskets involved with the valve body removal.
Pressure= 30-40 lbs is enough.
They will stand a crapload more than that, but I wouldn't go over 80 or so.
 
You must log in or register to reply here.
-

Back
Top