1964 Valiant automatic rythmic vibration

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CdnValiant

CdnValiant

1969 451-S
Joined
Sep 14, 2014
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Location
Cochrane Alberta Canada
My 64 Valiant 273 has a vibration that comes and goes in about 2 sec cycles from about 40 to 65 mph. I thought it might be the ball and trunnion at the front of the driveshaft, so pulled the driveshaft to check it out. As the transmission has a flange at the back, the car can be run without a driveshaft so I thought I would run it up in gear assuming it would be smooth. I started it, hit the pushbutton for drive and ran it up to speed and the vibration was there and the same. I tried it again in neutral and there was no vibration. It can't be anything behind the transmission and with it smooth in neutral, I would think the torque converter must be ok. Any ideas on what would cause this in the transmission. It was rebuilt about 2000 miles ago.
 
CdnValiant said:
My 64 Valiant 273 has a vibration that comes and goes in about 2 sec cycles from about 40 to 65 mph. I thought it might be the ball and trunnion at the front of the driveshaft, so pulled the driveshaft to check it out. As the transmission has a flange at the back, the car can be run without a driveshaft so I thought I would run it up in gear assuming it would be smooth. I started it, hit the pushbutton for drive and ran it up to speed and the vibration was there and the same. I tried it again in neutral and there was no vibration. It can't be anything behind the transmission and with it smooth in neutral, I would think the torque converter must be ok. Any ideas on what would cause this in the transmission. It was rebuilt about 2000 miles ago.
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just ck trans bolts all. mount and pull cover on front of trans and some how move converter. all that thuff is balanced. I would say something is loose as I said pull dust cover at that point flywheel will not move if torqconterter does .bolts r loose but u may have to replace flywheel and torqconerter bolts slack in this will wear torq converter bolts. next u replace converter slack has caused a worn out converter. bet all I own it. I have ball an trunnion as u call cars an a van. only way they go bad is no and I mean no lube these joints are as a wheel bearing packed if boot go bad may sling grease. out takes 50 yeara 2 go bad.
 
Thanks for the replies. I will go over all bolts. On the ignition question, I converted to an HEI electronic I bought on ebay. Seems to be a pretty good system other than the centrifugal advance springs which were way to stiff and the weights light so almost no advance until I modified it.
 
Was that a Pro-Comp distributor? A vibration every two seconds is a harmonics vibration. Probably not an imbalance but a power difference between cylinders. Maybe a vacuum leak to a single cylinder. I'd read the plugs; look for a pure white one.
 
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If it seems related to speed it will get worse and worse as the speed increases. The origin is often/usually behind the trans.
If it is related to engine, it will come and go as the transmission changes gears, and so changes the rpm.
The A-body has a natural oscillation which IIRC is around 50/60 cycles per minute. This can be aggravated or excited by the running gear and cruise-rpm; and is often very annoying at 55/60 mph, usually depending on the rear gear, and or pinion angle; especially if the rear ride-height has recently changed.It's been my experience that open windows can also excite this.
 
Here is a link to the distributor I used.
IMG_2536.JPG

HEI Distributor Small Block Mopar Dodge Chrysler 318 340 360 Complete Electronic | eBay
It came with a coil and plug wires. I attach a photo on my car. Not a stock looking coil.
 
Thats an E-core coil, good stuff for an electronic ignition. Have you checked your belt drive accessories? Pull all the belts and try again, you may have an imbalance in the fan or tossed a converter bolt. Id do a vacuum check too, look for a vibrating needle showing a bad cylinder.
 
pishta said:
Thats an E-core coil, good stuff for an electronic ignition. Have you checked your belt drive accessories? Pull all the belts and try again, you may have an imbalance in the fan or tossed a converter bolt. Id do a vacuum check too, look for a vibrating needle showing a bad cylinder.
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pishta said:
Thats an E-core coil, good stuff for an electronic ignition. Have you checked your belt drive accessories? Pull all the belts and try again, you may have an imbalance in the fan or tossed a converter bolt. Id do a vacuum check too, look for a vibrating needle showing a bad cylinder.
Click to expand...
 
What puzzles me is that the motor runs with no vibrations in neutral up to high rpm, so I think the motor and accessories are ok. With the driveshaft removed when I run it in drive parked in my shop, it vibrates from about 40 to 65 on the speedo. I will check all the bolts and re-install the driveshaft and run it up to the speed it vibrates on the road and put in neutral and see if anything changes. I will see if it is any different in 2nd also. The only recent driveline change was changing ring and pinion to 3.55 from 2.94 and changing to the appropriate speedo gear, but that wouldn't affect anything with driveshaft removed running in drive in my shop.
 
My experience with E-core coils is that mine liked a CDI Amplifier.
Mine ran horrible with the Orange box, and same with a Jacobs non-CDI . It was like yours; fine in neutral, but failing under load. I switched to an Accell Square-top Super Coil which ran beautiful with either of the former amps. That was early 2000s and that entire system is still on the car.
And the bonus was; that Yellow brute ran well into the 7000s, despite it being rated to 6500. And it idled rock-solid down to 550rpm (the lowest I needed it to), and was OK with long low-rpm periods. I couldn't wish for a better coil.
No other changes were made; just the coil/and matching resistor-swap.Mine is on the passenger side apron, a lil closer to the rad-support than to the firewall with about a 30 inch wire.
That E-core coil had ran perfect with a CDI amp. But the Amp died, so I tried it with the previous systems. After I got the Amp back, warrantied by Jacobs, (Thank you very much) it ran fine again..... but I didn't trust it. (Anybody want to buy it and the E-core, speak up)
That is my entire experience.
So I concluded that E-coils and CDI are happy together, and so are big fat welding coils and non-CDI amps, and never more should I mix them.
BTW; the plugs in this 367 (RN12YC Champion coppers) are the same ones I installed in 1999, and now have over 100,000 miles on them, and the SuperCoil is still firing them, at who knows what gap,lol. Click-vroom. I love that coil. I bought a spare set of plugs in 2004,that I was gonna install before I went to the races. They are still in the trunk. Car went 93 on the installed ones,so I called it good enough.
Your results may vary.
 
I have that same one on the bench still looking for the darn cap clips. It has a BOSCH '021' or '024' 4 terminal ignitor under the can, its not HEI as we know them. Its as simple as it can get VR+. VR-, 12V and COIL-, (heatsink is GND). Tried to look up the resistance of the matching BOSCH coil (85 Ford Telstar or Mazda 626ish) but if you want to run the matching coil to this ignition module, try and find the specs for a Bosch 0980AG0704 coil. Its not an E-core but a small potted coil with integrated bracket. The E-core models are HEC715 (female HT) or a HEC716 (male HT).
 
There is another one of these same issues on Big Block A Body Tech forum:
Driveline vibration out of now where! Help!

Sounds like pretty much the same issue, looks like we have it narrowed down to the Planetary Gears in the Transmission are wore out shot. The OP is still doing some more test like you have done here, he wants to find the problem for sure.
 
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Re-installed the driveshaft and checked torque converter and transmission mount bolts. Torque converter bolts weren't loose. but could be tightened so I pulled them, put on some blue Loctite and tightened them. On the test drive the vibration was still there, worse at about 50 mph. I shifted into 2nd and it went away. Tried coasting in neutral at 50 mph and there was no vibration. No big difference under load or coasting in drive. Other than the vibration getting stronger from about 40 to 50 mph and fading as I speed up, it doesn't seem to change relative to speed. I'm no expert in automatic transmissions, so any ideas on the cause would be appreciated.
 
If you were doing fifty in third then shifted to second; you went from not engaging any planetaries to engaging one set. But didn't your engine rpms double? Did you read your plugs yet?
 
Check the u-joint, did you check the wear pattern on the new gears?, and the ball and trunion a904 has some weird bearing at the tail shaft, might be bad
 
Here is a tail shaft out of a 727, there is a large Ball Bearing that supports the center of the shaft where the Key is in the picture.

904 uses the same type of bearing, we had a rough one on a 904 trans we were rebuilding that we had to replace. I might even have the part number yet if I can dig it up.

727 tail shaft.jpg


Notice that the Large Ball Bearing for the tail shaft is located just behind the speedo drive gear. The large bearing can be changed with the transmission still in the car.

If you want to try and see if the Large Tail Shaft bearing is bad you can pull out the speedometer drive, where the speedo cable screw onto. This will give you access to the tail shaft and the Large Bearing.

Look through the hole with a bright flash light to see if you can see rust or bearing damage.

Put your finger up in there on the tail shaft and slowly turn the driveshaft with your other hand in the proper forward rotation. If there is a bad bearing there you will feel the roughness in it as it conducts the vibrations to the tail shaft.

Side note: if you are going to remove the Speedo Gear to take a look at the Large Tail Shaft Bearing, take and mark the speedo gear aluminum flange (where the speedometer cable screws on) to the tail shaft housing with a dry marker. this way you can get it back in the correct spot to go with the plastic gear that is inside.

Prossess of elimination:

If you can determine that the tail shaft bearing is still good by this method but still feel a vibration or roughness of the tail shaft as it is turning then you know the damage if farther up the line into the transmission. And now it's time to pull the pan, see what is in the bottom, and check it out.

Any suspect transmission problems I have on any automatic car or truck, the first thing I do is drop the pan. This tells you the whole health of the transmission.

Pull the dipstick out of the automatic transmission and wipe it on to a clean white paper towel. Let us know if the transmission fluid color is Bright Red or Brown ?
 
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