1966 A904 loses all gears overnight

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Slantsix64

Slantsix64

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I drove my valiant ten miles and around for a couple days it shifted fine on point no slipping etc the next day it gets no gears it goes into park to keep the wheel locked but that it no reverse drive 1 2 3. Overnight weird so i changed the oil the filter was dirty, fresh oil new filter still nothings and before this i checked all the linkages ect it is engaging might it be the valve body inside? prior the trans was rebuilt about 6 years ago when it sat with no oil any ideas?
 
Sounds like may be converter drainback. Start it in neutral and see how soon you get gears. I have 2 96 Dakotas both v6 auto's. One has converter drainback and the other one doesn't. First Mopar I have ever owned that had that issue. Just a guess.
 
toolmanmike said:
Sounds like may be converter drainback. Start it in neutral and see how soon you get gears. I have 2 96 Dakotas both v6 auto's. One has converter drainback and the other one doesn't. First Mopar I have ever owned that had that issue. Just a guess.
Click to expand...
Drainback? should i flush out the convertor as well? thats the thing it gets no gears no jump no movement at all but i see and hear it changing gears at the valve body this is weird
 
Leave in neutral for a little, sounds like drain back. My 727 does this, but usually after sitting for several days.
 
Drainback is a short term problem, meaning once it runs for few minutes the converter will fill again and the transmission will engage and shift normally. Neutral range is where the fluid circulates best through the trans (unmodified torqueflites only). If this runs several minutes in neutral and still won't engage, the clutch packs are likely smoked, meaning time for another rebuild. This is likely the case since you also said fluid looked dirty. If fluid was brown or black, it's toasted.
 
In the business that is called "Morning Sickness" and is caused by hardened up rubber seals.
Hardened up seals don't flare out like they are supposed to, and don't seal against the drum/piston surfaces.
(Meaning a soft parts rebuild at the least)

If the fluid is burned it probably happened from trying to make it go anyway.

Converters only take about 5 seconds to refill from drainback.
 
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TrailBeast said:
In the business that is called "Morning Sickness" and is caused by hardened up rubber seals.
Hardened up seals don't flare out like they are supposed to, and don't seal against the drum/piston surfaces.
(Meaning a soft parts rebuild at the least)

If the fluid is burned it probably happened from trying to make it go anyway.

Converters only take about 5 seconds to refill from drainback.
Click to expand...
Ya I'll try that out the oil was dirty but it wasn't burnt or smelled. But I think your right those rubber seals probably was dry and cracked I'm going to take another look after school see what's going down. Thanks for the feedback
 
although you hear the detent inside the transmission when you move the shift lever you need to make sure it is actually moving the shift valve in the valve body. The other thing is the lugs on the front pump if they are broken off no pumping oil. You can check this by loosening one of the cooling lines to see if fluid comes out when it's idling.
 
Trail Beast hit it on the head. Lip seals are have probably gone hard after sitting for six years.
 
Slantsix64 said:
I drove my valiant ten miles and around for a couple days it shifted fine on point no slipping etc the next day it gets no gears it goes into park to keep the wheel locked but that it no reverse drive 1 2 3. Overnight weird so i changed the oil the filter was dirty, fresh oil new filter still nothings and before this i checked all the linkages ect it is engaging might it be the valve body inside? prior the trans was rebuilt about 6 years ago when it sat with no oil any ideas?
Click to expand...
I re-read the op's original post. Worked perfect for 2 days then nothing. That's a different thing.
 
Low fluid?
Checking running in neutral?
Sometimes this gets missed......
 
Since the VB is factory stock, you cannot manually select second or third.You can only select reverse, manual low, and Drive-low. What I mean is, if you select second or Drive, the trans will default to Drive-low

As to no-forward motion in Drive-low, the only choices are the pump, the manual valve, and the over-running clutch.
The over-running clutch cannot be diagnosed except by inference when everything else checks out OK. But it rarely fails in a stock application. I have seen maybe half the energizing springs worn thru, and it still drove normal.
A somewhat common problem in this situation is a disengaged manual valve. A pressure test will reveal it.Alternatively, you can check the manual valve, by removing all the link-rods down at the trans and shifting the trans thru all the gear positions , and listening for each little click, and feeling each little notch,and finally;checking for the presence of the E-CLIP that keeps it all together.

As to manual low and reverse:
The common denominator is the L/R band.And the adjuster is in the pan......... So you have two options;
A) put a pressure gauge on it to prove the pump is working, and
B) if it is, then pull the pan again and verify that the strut-adjuster is still engaged, and adjust that band.
C)If no pressure, put it in neutral and verify there is adequate fluid in there. If the level is correct with the engine idling in neutral, then the trans will need an overhaul.
D) If after the strut is found to be engaged, and the band has been adjusted, and you still cannot get the car to move, then you have two options;
E) drop the pan again,lol, and perform an air pressure test on the L/R servo, and
F) just get it overhauled.
G) you can do step E), at B) after the band has been adjusted and save removing the pan a second time
I think 67 was the first year of the anti-drainback valve.

That's all I got
 
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Thanks for all the advice fluid level is correct. I'm going to unplug the transmission line at the radiator and see if there is pressure or anything and go from there. I do have a extra front pump that was working but it's from a 67 a904 273 would this work with a slant six 904
 
Slantsix64 said:
Thanks for all the advice fluid level is correct. I'm going to unplug the transmission line at the radiator and see if there is pressure or anything and go from there. I do have a extra front pump that was working but it's from a 67 a904 273 would this work with a slant six 904
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The cooler line is a low-pressure lube line,only. It won't tell you much other than the line is clear. If it was plugged it wouldn't make any difference to the trans operation, only to it's life.
The pumps,I imagine, are the same, but it's not likely that your trans has a pump problem. In fact, I would say it's highly unlikely.

The most likely problem is the manual valve.and
the second most likely is the L/R band. I have seen the anchors break off and the strut falls out. And then nothing works....just like in your case.
As to the manual valve, it may just be that the roostercomb inside is not synced up with the shifter. I've been fooled by this before when the manual valve was not correctly detented and then it either dumps all pressure into the pan, or it blocks pressure to the rear clutch.In either case the result is the same, no drive in any position
Oh that brings up another point, If the manual valve is not synced up, then it is also possible that in neutral, fluid will not be directed to the TC. So, I suppose it's possible in this case, for the fluid level to be correct in the pan, but the TC could still be half empty....... and same no-drive symptom. So I think it would be prudent to start at the shifter sync
 
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If a steady stream of fluid pours from the line that comes from the front fitting on the transmission while running, checked at the cooler, you can assume the the pump and converter are OK, the converter hub is not broken. No fluid at all from that same line while running means trans has to come out. Fluid coming from that line means pull the pan and check for the linkage AJ mentioned, but you are only looking for the bent steel comb that has the detent teeth to have a small tab engaged with and moving a cylindrical valve partially exposed from the valve body. If all is good, trans comes our for teardown inspection. Front fitting on trans comes from pump as cooler pressure, rear fitting is returning fluid to trans by lubing the rear support at the back of the trans case.
Edited to remove mention of wire/rod connecting the comb to the manual valve. Torqueflites don't use that. I had a recent 700R4 on my mind. Sorry for mix up.
 
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Update. So the valve body is working I saw it operating with the pan off. Problem the front pump the oil is not circulating at all I un hooked trans lines and nothing came out after idling and in drive for about 10 minutes. And I do remember once I had a leak in a trans line and it shot out bat **** crazy. So I'm going to pull it out tomorrow. I will also check the converter and see if it's clogged inside or something. Thanks every one I do appreciate the advice. Also would I need to buy a new front pump or is it rebuildable
 
Don't worry about parts until it's out for inspection, unless you need it as a daily driver right away. Converter won't be plugged, but the hub that drives the pump may be broken as others have mentioned. Pump is usually serviceable unless a broken converter hub chewed it up too bad.
 
It will be interesting what happened here. Trannys usually don't work good one day and break while setting overnight. You can loose foreward gears buy breaking a planetary but you need 500 horse and a heavy car with lots of bite. You will still have reverse though. LOL (a friends 70 Superbee with a +.030 440 dyno'd at 497 hp.)
 
Slantsix64 said:
Update. So the valve body is working I saw it operating with the pan off. Problem the front pump the oil is not circulating at all I un hooked trans lines and nothing came out after idling and in drive for about 10 minutes. And I do remember once I had a leak in a trans line and it shot out bat **** crazy. So I'm going to pull it out tomorrow. I will also check the converter and see if it's clogged inside or something. Thanks every one I do appreciate the advice. Also would I need to buy a new front pump or is it rebuildable
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This is not a proper diagnoses.
At Idle and in park the manual valve, Assuming it is properly detented by the rooster comb, dumps almost all the line pressure into the pan. You could be running as little as 5 psi.The TC control valve would then also be seeing 5psi. And the TC could be seeing less. And the cooler is after the TC, so if the TC is not moving fluid,guess what,none comes out the line.
The proper test is to install a pressure gauge into the L/R servo and rev it up to 1000 rpm, looking for in excess of 230 psi......in REVERSE;A properly detented reverse.
I highly doubt,in this case, that you have a pump issue.
So suppose that you pull it out, and the pump is dandy fine, and the TC hub is too; then what? You now have no way to continue the diagnoses..... now you have to do a complete tear down and HOPE you find the real problem.
But suppose you don't find a problem, do you then put it back together and slam it back in,HOPING for the best? And then when it works the same, what will you do then?
I don't know about you, but I wouldn't be taking it out until I KNOW what the problem is. I hate taking trannys out in the first place, and I sure don't want to be doing it more than once.
And there is a very good chance, that this is not a mechanical issue.............
unless the L/R band is not functioning, or the manual valve is not properly detenting.
Nevertheless carry on,lol.
 
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Low/reverse servo and band are not used in drive range for first gear; the one way roller is. There is only a few things that will cause absolutely no forward and no reverse ranges at all, and most of them are already ruled out from his previous inspections. The one and only 904 that I personally had shear off a converter hub never made an unusual sound and just felt like it went into neutral while driving down the road at steady speed. Testing pressure would rule this out.
 
When reverse is selected, All regulation is supposed to be negated (except for the hi-pressure relief),and the pump is at maximum pressure. Ergo the only obvious points of pressure loss are the L/R servo, the Front clutch, and the manual valve.
If the pressure is weak the flexplate bolts are proved, and the tranny comes down. If the pressure is good, we know at least those items are OK and we move to the next test. I cannot think of a better pump test.
I suppose the regulator valve could be stuck, but A) if it was you would see it on the gauge, and B) if the trans has that much debris in it I'm rebuilding it. And of course if it was stuck, this would explain no output from the cooler line.
I suppose the hi-pressure relief could be stuck open.
I suppose the L/R band could be busted
I suppose the servo could be popped out
I suppose a lot of things
But my first go-to is the maximum pump pressure test.
 
AJ/FormS said:
This is not a proper diagnoses.
At Idle and in park the manual valve, Assuming it is properly detented by the rooster comb, dumps almost all the line pressure into the pan. You could be running as little as 5 psi.The TC control valve would then also be seeing 5psi. And the TC could be seeing less. And the cooler is after the TC, so if the TC is not moving fluid,guess what,none comes out the line.
The proper test is to install a pressure gauge into the L/R servo and rev it up to 1000 rpm, looking for in excess of 230 psi......in REVERSE;A properly detented reverse.
I highly doubt,in this case, that you have a pump issue.
So suppose that you pull it out, and the pump is dandy fine, and the TC hub is too; then what? You now have no way to continue the diagnoses..... now you have to do a complete tear down and HOPE you find the real problem.
But suppose you don't find a problem, do you then put it back together and slam it back in,HOPING for the best? And then when it works the same, what will you do then?
I don't know about you, but I wouldn't be taking it out until I KNOW what the problem is. I hate taking trannys out in the first place, and I sure don't want to be doing it more than once.
And there is a very good chance, that this is not a mechanical issue.............
unless the L/R band is not functioning, or the manual valve is not properly detenting.
Nevertheless carry on,lol.
Click to expand...
Looks like I was correct
 
Thanks for the replies much appreciated I'll upload some photos once I get a chance
 
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