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1958 Variable pitch dynaflow whirring at all ranges in low speed.


P6tu

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Hello,

 

My car has this humming of whirring sound in all ranges at low speeds with poor performance. The symptoms are perfectly described in the chassis manual with hints of checking the passages at valve body and the reaction shaft flanges.

Now the transmission was taken out and everything was checked and all seemed to be good, but the problem remains. Does anyone have any ideas, what to check? Since I'm in EU, then aquiring a proper oil pressure gauge that would fit takes time (hopefully I'll get something today). Due to that I don't have the oil pressure results to aid in this issue - but maybe someone has some ideas to throw out already with the given description.

 

With best regards,

P6tu

Edited by P6tu (see edit history)
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There is not much information to work with here. Humming could be tires although that would normally be audible at higher speeds. Whirring and humming could be front wheel bearings or outer rear end wheel bearings. Humming could be brake shoes too tightly adjusted. 

 

May I ask if you have checked rear axle lubricant level?  How old your tires may be and if they are bias ply or radials?  And, most importantly a much expanded definition of what poor performance means?

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The whining noise is related to transmission. That much is already certain. The noise is only apparent when the gear is either D, L or R. In neutral everything is fine.

Poor performance in sense that the acceleration from 0-40 is ... very bad as if the transmission clutch is slipping. When the transmission was taken apart, then I can tell that both of the pumps are in top shape, the pump plate is clean and has no wear, the clutch pack is like new. I did replace the low band. it was a bit worn and I tought that maybe that has something to do with it. There are some rust markings (VERY OLD ones) on the flange shaft, but if those would be the ones causing the problem, then it should have been a long itme ago, since the rust places were there already then. The transmission has been taken apart about 3 years ago and everything was replaced already then (besides the low and high bands).

When the car has reached 40+mph, then the performance is as it should be.

And just in case - as mentioned, the valve plate and the flange has been precisely checked and cleaned. There was this graphite like excess debris or rather mass as you would expect if you had burnt your clutch or bands, but as stated, only the low band looked like worn out... But not that much. I can add pictures of the old one, but compared to the new one, it wasn't so bad. And I can not find anything or any source for this graphite like mass.

Ouh, and also, the variator blades are all in neat condition and have no bents nor loose blades in the turbine.

 

For me, as much as I have investigated the chassis manual and made the things clear for myself, then it looks like there is no pressure forming in the small inner turbine. When the transmission was taken apart, then I had my hopes in some clogged passages in the reaction shaft flange, but there wasn't nothing apparent there and as stated, cleaning did not change anything.

 

About todays achiecements so far - I have not been able to get a pressure gauge to use in those measurment points at the actuators, front and rear pumps... That would definitely narrow down the location of the cause, but still, seems like everything that can be, has already been checked and I have no idea, what I am missing.

 

I will be heading to the garage again today and I'll try to fiddle with the "kickdown" linkage and see, if that makes any changes...

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3 hours ago, P6tu said:

I have not been able to get a pressure gauge

Very important as you know.  In the meantime check the linkage for proper adjustment.  There is also the possibility of the wrong gasket used on the valve body.

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3 hours ago, TexasJohn55 said:

One question. When you are taking off at normal rate at about 20 to 30 mph and then floor the throttle, does the engine immediately rev up and acceleration improve for a few seconds?

Can't quite tell so... Maybe a little, but it is not so well to differentiate. But if you floor it at 50mph, then you can definitely feel the torque and acceleration.

 

1 hour ago, JohnD1956 said:

Has the universal joint in the drive shaft been checked?

Yes, both of them (there are two).

 

1 hour ago, old-tank said:

Very important as you know.  In the meantime check the linkage for proper adjustment.  There is also the possibility of the wrong gasket used on the valve body.

Sad story is, that I was not able to get a suitable pressure gauge... Well, actually I know, where to get the gauge, but the problem is about getting a proper end to screw in (metric vs imperial issues).

Regarding the seal - it worked very well before. Just at the end of last season it suddenly started acting like that after hitting the pedal a bit harder at the green light (nothing hard and not exactly flooring). Before that the transmission worked and functioned as it should.

Edited by P6tu (see edit history)
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Since this transmission fix will seem like a long term project on it's own, then I am leaning towards swapping the transmission as a whole in general for this summer or maybe even for a longer term. I've been working on this transmission for this whole winter time.

 

Is there any newer transmission that would not require the torque tube to be replaced with an open driveshaft and would not require any alternations to the car and car frame? Has anyone maybe done it already? I read something about someone doing something to a 322 engine, but there is no update afterwards...

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1 hour ago, P6tu said:

Can't quite tell so... Maybe a little, but it is not so well to differentiate. But if you floor it at 50mph, then you can definitely feel the torque and

At any speed from 20 mph up, you should hear the engine rpm increase when to go to full throttle in Drive range. If you cannot tell,  you need someone to operate throttle in car while you check linkage arm travel at the accumulator. You could also remove linkage at accumulator and stroke the lever by hand to check limits of travel and spring tension.  If the accumulator is changing the pitch of the convertor, it will be noticeable when driving normal vs full throttle. Again,  You must put a guage on it to test those function pressures.

 

As an alternate test, you could wire the lever at full stroke on the transmission and test drive for performance. It should be noticeably improved.

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8 minutes ago, TexasJohn55 said:

"As an alternate test, you could wire the lever at full stroke..."

Could you ellaborate a bit? I do not quite understand, what do you mean by wiring the lever at full stroke :S ?

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3 hours ago, P6tu said:

Could you ellaborate a bit? I do not quite understand, what do you mean by wiring the lever at full stroke :S ?

The small lever at front left on the transmission is operated by linkage to the throttle linkage at the carburetor. It  only actuates the lever at the trans when near full throttle when adjusted properly. After verifying that the throttle does move the lever at the transmission, you can use wire or a plastic zip tie to keep it locked at full stroke. It would be best to disconnect the linkage rod at the transmission before locking the lever at full travel against the internal spring tension.

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5 hours ago, TexasJohn55 said:

The small lever at front left on the transmission is operated by linkage to the throttle linkage at the carburetor. It  only actuates the lever at the trans when near full throttle when adjusted properly. After verifying that the throttle does move the lever at the transmission, you can use wire or a plastic zip tie to keep it locked at full stroke. It would be best to disconnect the linkage rod at the transmission before locking the lever at full travel against the internal spring tension.

I did try that. I can't say that the performance would have increased and it was rather the same (no effect). I understood, that this is the "kickdown" switch... But there was one change when changing that link position - when I switched to drive and then pushed the link up (like it would with full throttle) against the spring tension, then the whistling/whirring noise went lower (but did not dissapare). After that I put it in full throttle position with a ziptie and tried to drive - but couldn't tell a big difference.

But what I find a bit strange about it, is that when the engine isn't running, then there is no spring pressure on that "kickdown" link at all - is that normal?

About adjusting the rod attached to the linkage - can I do it without taking the high accumulator off from the flange?

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On my 55, from memory, there is always spring tension. The adjustment is done at the linkage on the firewall.  It has become obvious that you need a shop manual for your car, it will answer all your questions about adjustments and troubleshooting.

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  • P6tu changed the title to 1958 Variable pitch dynaflow whirring at all ranges in low speed.
11 hours ago, P6tu said:

Just in case - picture of the link that I describe as a "kickdown" switch.

IMG_20210601_190525.jpg

 

That transmission appears to be too dirty to have been recently serviced.  Some of that dirty may be inside causing the problems.

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4 hours ago, old-tank said:

 

That transmission appears to be too dirty to have been recently serviced.  Some of that dirty may be inside causing the problems.

I didn't clean the exterior, but I did clean the interior... Didn't make much pictures, but:

IMG_20200806_204012.jpg

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But the servo was the easy part... After cleaning that, I didn't see any changes and had to take the transmission out. But I cleaned everything inside and took apart most of the elements (turbine vanes, clutch pack, both bands, pumps and the flange). I did not do anything with the accumulators and I didn't disassemble those to bits and pieces. Just took them away from the flange plate (damn tricky with one nut instead of a bolt which was not needed to be fully loosen)...

Only thing, that appared a bit different was the low band, when compared to the inside of the high band. So I replaced that. I could not say, that it was exatly worn out, but just had a strong hint of being used. I had the band adjusted to max also prior to installing the new band, so I tought that this was the culprit, but nope. I adjusted the bands according to the book by tightening it and then 6 turns back - did I do it incorrectly? The high band works perfectly...

Edited by P6tu (see edit history)
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On 6/1/2021 at 7:38 PM, TexasJohn55 said:

It  only actuates the lever at the trans when near full throttle when adjusted properly.

Correction: The 58 Manual states that it begins actuation at appx 1/2 throttle. This is different than the 55 Manual. As it is not clear if we are troubleshooting a Twin Turbine or Triple Turbine Flight Pitch Dynaflow, or what yr the transmission is, I will now leave this conversation for others more intimate with Dynaflows.     TJ55

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I made a few videos also that show and explain the issue.

 

This video shows the poor performance (stationary acceleration with the lever in D position):

 

In this video I tried to capture the sound (video starts with lever in N and then followed by D, L ...some struggle with lever position change by a girl :D... R and the  back to L, D and finally N):

 

If someone could specifically point me what to exactly look for, I'd be greatly thankful. From all the troublshooting tips it all directs to issues in the reaction shaft flange (the plate that has oil passages that route the pressure either to the small turbine or big turbine and etc.), but since I cleaned it all, then I am a bit lost... What also troubles me, is that with the speeds over 30mph, the performance is normal, with the exeption, that it does not have this increased humf, when flooring it and does not have that specific sound that it used to have, when the acceleration pedal was pressed all the way down within speeds between 20-60 mph.

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9 hours ago, avgwarhawk said:

That's a very significant whirring noise. Maybe a front pump issue as over 30 mph it performs ok. 

Would look like that, but the pump plate didn't have any worn markings and even the old plate looked worse and even that performed better (4+ years ago). The offset half moon looking things were properly tight and I find it hard to believe, but maybe I did miss something... I really need to get something to measure the pressure...

 

Maybe I am looking for the pressure gauge with wrong words, but would someone be able to help me find a proper strut to measure the pressure from the front pump? All the measurment points seem to have the same thread, but I am not able to get anything in EU. I can get the high pressure hose and the gauge to measure up to 400psi, but I just can't get anything to fit and tighten in the measurment points on the transmission...

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  • 1 month later...

319093688_dynaflowtroubleshootingnoises.jpg.77c771f9d508e1e7bd03d788d6b66ba8.jpg

You really need to get the manual and check for "main line" pressure port. Measure the pressure. That way we can know what you're up against.

From what the video has for the whining sound, it sounds like it is coming from either the front pump, torque converter, or even bearings that carry torque converter, input shafts, etc.

Edited by d2_willys
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