A904 has reverse no foward

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Madhatter1776

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Ok, this is the story, 75 duster 360 from truck a904 from 81 imperial, was driving, lost motion till I turned the key off, restart drive for about 1/4 mile lose everything, had trans rebuilt prior to install, so it was rebuilt, did not replace converter, ok so removed trans pan, found nothing out of the ordinary in pan, some clutch material ect. remove filter, found that the speedo gear pieces I installed (wrong) chewed up on top of filter, removed trans and inspect a few things, reverse band good, both drums and clutch disks and steels still in good shape, replaced pump(found gouge) replace converter, reinstalled, now I have reverse and no drive at all, thinking no pressure in valve body possible plastic from gear stuck somewhere in vb. Any other suggestions would be greatly appreciated, and again, thanks a bunch in advance
 
...............Well, I don't know if I can help u, but the same thing happened to a friend of mine back in 1981.......changed a lot of different parts including a new valve body, still no forward gears, I never knew anything about trannys then, but I suspect that maybe the over running clutch was assembled wrong...........first thing I would do is check the pressures from the ports on the outside of the tranny, did it get air checked b4 the valve body went in...........kim.....
 
Did you check the piston in the rear (forward) clutch stack? Reverse uses the direct clutch and the low-rev band, but forward gears require the forward clutch to be engaged. If the lip seal is toast then you can get what you have.

An air test or pressure check should be revealing.
 
Well, I had the trans done when I swapped out the slant 6, so last summer I drove the car and was fighting a different issue, so this is a new issue, I was driving to work when I got it to about 50mph, then it quit going, from that point I had to stop the car wait about a minute, then restart and drive about 1/4 mile, then it would quit moving, rinse and repeat till I got home, after that is when I pulled the trans out etc. come to think of it, would there be a difference if I swapped out the VB from my slant 6 a904?
 
Rather than swapping parts you need to diagnose the problem. I'd do a pressure test and if that looked ok I'd drop the valve body and air pressure check the clutch packs.
 
Well, I had the trans done when I swapped out the slant 6, so last summer I drove the car and was fighting a different issue, so this is a new issue, I was driving to work when I got it to about 50mph, then it quit going, from that point I had to stop the car wait about a minute, then restart and drive about 1/4 mile, then it would quit moving, rinse and repeat till I got home, after that is when I pulled the trans out etc. come to think of it, would there be a difference if I swapped out the VB from my slant 6 a904?

If it worked and then quit, something wore or broke. The valve body may or may not be an issue, or contributing.

The forward clutch is engaged in all forward gears, if you suddenly lost forward gears and then it came back when cool, I would suspect clutches and steels or a lip seal. A pressure test should reveal a lip seal issue.

You said clutches looked good, how so? Was there still grooving visible on the faces? Or were they perfectly smooth? What was the pack clearance?
 
If it worked and then quit, something wore or broke. The valve body may or may not be an issue, or contributing.

The forward clutch is engaged in all forward gears, if you suddenly lost forward gears and then it came back when cool, I would suspect clutches and steels or a lip seal. A pressure test should reveal a lip seal issue.

You said clutches looked good, how so? Was there still grooving visible on the faces? Or were they perfectly smooth? What was the pack clearance?

Well when it quit I had nothing, you could only let it idle, if you hit the gas the engine would rpm real high, I had at firsts though maybe the linkage come undone, but that was not it, turned off the car, without knowing, restarted to check if i had reverse, then I had everything back for about 1/4 mile etc. since the trans has been rebuilt with less than 5,000 mile on Ill wager, I figured maybe the front pump or the torque converter, when finding out prices some trans place's told me that it sounded like it was sucking up something, clogging, which would be why I lost everything, until I shut down and restarted. Now to be fair I had planned on replacing the convertor with a high stall anyway so no biggy there, I really did not care if it was the converter or not since I was pulling the trans anyway now was the time to put one in so I got a 2500 stall, also this is a lock-up trans ( found out the hard way) When I removed the pan and filter to inspect for anything I did not see anything to wright about except for the plastic speedo gear pieces on top of the filter. So natch I figured that must have been the issue, after removing trans, I did inspect the first two drums and clutch packs. They look new, not worn at all, one steel had a bit of bluing from getting hot a slight sent of burnt oil, but everything looks good including fluid that I drained, even in the pan there was debris you would expect to find, did not go further, replace front pump because we found a gouge, so just for good measure. reassembled. Now we run it with jack stands through all gears, you can tell its in reverse, however when it is in N-1 tires will go forward just not with the car on the ground, engine does not over rev, it acts like it stays in park or neutral. Its does take a bit of pedal to get them to move however. I will do some pressure check's, however I do not know which ports to use, so some help there would wonderful, also before all this, there was a noise in low gear that happened ever since I got it back, its hard to describe with words, It was like a slipping noise, it would happen as you got moving, just when you would hit the gas to go , one time every time, the morning that it quit, that noise was like an extended version of it, it never did anything like hard shifting or anything, just that slip like noise, I wonder if something in the VB has been going all this time and just let loose, The car don,t move so I don't hear it now, maybe that might help as well. Again this sight is great I hope I can help out some folks as I gain some exp with what I am doing, and thanks in advance and thanks FABO.
 
Was your kickdown linkage connected correctly?

I hate to say it, but if the steel is blued at all, it was slipping and those clutches/steels are probably toast. Any smell of burnt anything indicates something was wrong and is not kaput. Hard to say without a clutch pack clearance measurement, or pictures of anything. But the 'sounds in first gear' and lack of hard shifts are all pointing at a slipping clutch pack.

Again, the forward clutch is engaged in all forward gears and you have no forward gears but do have reverse. Reverse does not use the forward clutch, so something is up with that clutch (it's the one furthest to the rear).

Something could be jammed up, not letting that pack get fluid and thus not engage, but that's a quick air check.

Your filter should stop any larger debris from entering the valve body.
 
Was your kickdown linkage connected correctly?

I hate to say it, but if the steel is blued at all, it was slipping and those clutches/steels are probably toast. Any smell of burnt anything indicates something was wrong and is not kaput. Hard to say without a clutch pack clearance measurement, or pictures of anything. But the 'sounds in first gear' and lack of hard shifts are all pointing at a slipping clutch pack.

Again, the forward clutch is engaged in all forward gears and you have no forward gears but do have reverse. Reverse does not use the forward clutch, so something is up with that clutch (it's the one furthest to the rear).

Something could be jammed up, not letting that pack get fluid and thus not engage, but that's a quick air check.

Your filter should stop any larger debris from entering the valve body.

Yea the kickdown's hooked up right, one day it fell of for some reason, that was an interesting ride home, there was no large debris in the pan, just chunks of plastic on top of the filter, before I panic and pull the trans again, I am going to do an air check, do you know which ports I use for that? I can not tell ya the clearance as I did not do the rebuild, so I have no idea.
 
ok so after some testing the trans does have to come back out, what exactly do I have to do to insure that the kickdown linkage was indeed hooked up right, because unless there was a problem from the time of the first rebuild, I can not figure out what happened, I tore apart the valve body and did not see anything, the air test reveals a much louder air sound in the forward clutch than the reverse, so it may just be a lip seal , but now I am not sure. I ordered a rebuild kit and am going to replace the clutches and steals and any seals.
 
Sounds like you've found your problem. It could also be the reaction shaft sealing rings leaking. They seal the port to the front clutch so if their not sealing it'll leak similar to a front clutch leak.

The throttle pressure (kickdown) linkage just needs to be hooked up so that when you floor the pedal the linkage pushes the lever down on the trans either all the way back or real close to all the way and when the carb is at idle the lever down on the trans is forward almost all the way if not all the way forward. In other words the linkage should cause the trans lever to move in sync with the carburetor throttle
 
The throttle pressure (kickdown) linkage just needs to be hooked up so that when you floor the pedal the linkage pushes the lever down on the trans either all the way back or real close to all the way and when the carb is at idle the lever down on the trans is forward almost all the way if not all the way forward. In other words the linkage should cause the trans lever to move in sync with the carburetor throttle

And one drive home without it will fry your trans. That's probably what happened, especially if you had a decent amount of clutch material in the pan.
 
And one drive home without it will fry your trans. That's probably what happened, especially if you had a decent amount of clutch material in the pan.

Yep. Don't take much. When I was a kid 904's got a bad reputation of being junk and I bet a lot of the time it was because the throttle pressure linkage was either missing or out of adjustment.
 
FMVB will fix that kick down issue right now! I don't like kick downs myself. I would rather shift that B&^$!cH, haha

I am putting some pretty good power through my 904. Motor is about 520ish and I hit it with another 200 of NOS.

I would say at least 650hp and same if not more Torque to the tires. I am switching to EFI and Procharger as I type this. It probably won't last too long with the new power...... 1000hp to the tires. I have a done up 727 on the stand ready to take its place. Lol
 
Ok, so after multiple time in and out and testing, I have found that I put a plate in upside down, and I was missing a clutch disk, now I have forward, I have adjusted the kick down, after being shown how. Now I figured out the problem in the first place was that I do not have second, I can feel it go from 1st, then right through to 3rd, If I manually move from first to 3rd, it will stay in second until I shift, but it wont do it on its own, any suggestions on where to go?
 
Ok, so after multiple time in and out and testing, I have found that I put a plate in upside down, and I was missing a clutch disk, now I have forward, I have adjusted the kick down, after being shown how. Now I figured out the problem in the first place was that I do not have second, I can feel it go from 1st, then right through to 3rd, If I manually move from first to 3rd, it will stay in second until I shift, but it wont do it on its own, any suggestions on where to go?

If it shifts correctly when you manually shift it the problem is either in the valve body or within the governor but since you say it starts out in first then shifts to 3rd that rules out the governor. My guess is it's possibly a weak 2-3 shift valve spring which allows it to shift into 3rd immediately after shifting into 2nd. Here's a PDF file showing the valve body. You can see the 2-3 shift valve and spring on the pic in the middle of the page
 

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If it shifts correctly when you manually shift it the problem is either in the valve body or within the governor but since you say it starts out in first then shifts to 3rd that rules out the governor. My guess is it's possibly a weak 2-3 shift valve spring which allows it to shift into 3rd immediately after shifting into 2nd. Here's a PDF file showing the valve body. You can see the 2-3 shift valve and spring on the pic in the middle of the page

Is it replaceable and if so where, I can not seem to find it on the interweb.
 
Is it replaceable and if so where, I can not seem to find it on the interweb.

It's replaceable but I've never found new ones listed. I have several old valve bodies that I've gone through saving good parts from. I can send you one if you need it.

Just so you know, this is just my guess as what the problem could be by the description you gave. No guarantee it'll fix it but by your description of how it acts it's what I'd check first.
 
It's replaceable but I've never found new ones listed. I have several old valve bodies that I've gone through saving good parts from. I can send you one if you need it.

Just so you know, this is just my guess as what the problem could be by the description you gave. No guarantee it'll fix it but by your description of how it acts it's what I'd check first.

Does it matter then if it come out of a non lock up, I know that the v-bodies are different between the two, as I believe that the lock-up has a extra valve( seen the difference on u-tube) I do have an old one that was with the slant-6 I believe is a non lock up, wonder if I can swap spring's, plus I have a 727( I know I should have used but I have got some money in this A-904 now I am slightly regretting it) are the v-bodies interchangeable? also I do not get mad at folks for suggestions, I realize that its hard to type sounds and descriptions over the internet, or even over the phone for that matter, I have guessed myself and even had others help and not have been right, hell last year I had an overheating problem that I spent some money trying to fix, in the end it was the water pump(go figure)plus all the time I have spent pulling and re-installing this trans.I really just appreciate the help and advice this sight gives, I only hope I can help folks as I get a little better myself.
 
Does it matter then if it come out of a non lock up, I know that the v-bodies are different between the two, as I believe that the lock-up has a extra valve( seen the difference on u-tube) I do have an old one that was with the slant-6 I believe is a non lock up, wonder if I can swap spring's, plus I have a 727( I know I should have used but I have got some money in this A-904 now I am slightly regretting it) are the v-bodies interchangeable? also I do not get mad at folks for suggestions, I realize that its hard to type sounds and descriptions over the internet, or even over the phone for that matter, I have guessed myself and even had others help and not have been right, hell last year I had an overheating problem that I spent some money trying to fix, in the end it was the water pump(go figure)plus all the time I have spent pulling and re-installing this trans.I really just appreciate the help and advice this sight gives, I only hope I can help folks as I get a little better myself.

The springs are interchangeable from any 904/727 valve body so the one from the slant VB will work. The only thing is it might be a weaker spring and not do you any good. You could compare them and see. You could also compare the one from the 727 VB and see which is longer and use the longest one. The 727 valve body is interchangeable except for one thing. The spacer plate dividing the two halves of the valve body needs opened up where the mounting hole is elongated. The lower main valve body half is already open. I don't know why ma Mopar couldn't have also elongated the spacer plate unless it was a ploy to make sure the assemblers didn't get 904 and 727 bodies mixed up.
 
Are you sure the tranny was not overfilled? If the fluid gets aerated from the guts whipping it up, and that aerated-fluid gets into the circuits, I imagine it could do all kinds of weird things. At shut-down, the bubbles would burst, and you have a reset. Then it would take a while to whip the fluid around again at hi-way speed.
Overfilled usually pukes oil out the vent, tho
This is a theory
 
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