The vibration that won't quit, what's next???????????

[Lets Roll]

What type of Brakes do you have? I had a problem like this on a 72 dart and after replacing u joints and checking everything it turned out to be a brake problem. I wasn't trying to solve the problem at that time It just needed brakes and I replaced a lot of parts, hoses and calipers etc. Then the problem was gone! It was weird.

 

[1966satellite]

Got that, put it together the way it came apart and referred to the manual for insurance so that's good.

Have you checked the fuel filler tube and the Body brace behind the rear seat?

 

[747mopar]

Have you checked the fuel filler tube and the Body brace behind the rear seat?

You lost me on that one?

 

[1966satellite]

vibration

You lost me on that one?

The fuel filler tube can rattle against the frame and if the weld on the brace behind the rear seat has broken, you can get a rattle/vibration there. I know they're long shots.

 

[dieseldazzle]

Does the motor vibrate at a dead stand still while revved and held to say 4000 rpm?

Didnt to read through all the pages I'm on my mobile device

 

[747mopar]

The fuel filler tube can rattle against the frame and if the weld on the brace behind the rear seat has broken, you can get a rattle/vibration there. I know they're long shots.

Gotcha, anything is worth a shot.

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Does the motor vibrate at a dead stand still while revved and held to say 4000 rpm?

Didnt to read through all the pages I'm on my mobile device

Smooth as silk, when I built the motor I had the whole rotating assembly balanced. I can mash it and shift at 6,000 rpm threw all the gears until I hit 60+ mph before there's any hint of a vibration and then it doesn't matter what gear your in as long as it's 60+ mph and gets worse if the load is removed (push clutch in or cresting a hill).

 

[dieseldazzle]

Also my 67 charger had a vibration I couldn't track down till one day I heard a clunk and seen my fan belt fly out from under the car. My vibration went away immediately. Needless to say it was my clutch fan and that wore out my water pump bearing cuz I had to replace both.

 

[masshole73]

I had a serious vibration at exactly 55 mph...after about half a year of just dealing with it I found it to be the steering box bolts were all loose..and one was missing! Don't overlook the small stuff.

 

[Dennis H]

As described in the 3 pages above, dismantle entire vehicle. Look, I've got some kind of whirring sound when decellerating 25-5 mph. Never found it. I suspect the Dana. I give up.

 

[Coronet 14]

Can any of the shops in your area ballance the Tire on car. it would also show up a vibration

[video]https://youtu.be/7UP97bO-MpU[/video]

 

[747mopar]

Can any of the shops in your area ballance the Tire on car. it would also show up a vibration

[video]https://youtu.be/7UP97bO-MpU[/video]

Don't know of any but I can look.

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As described in the 3 pages above, dismantle entire vehicle. Look, I've got some kind of whirring sound when decellerating 25-5 mph. Never found it. I suspect the Dana. I give up.

I may be able to overlook some noise but not something that makes you question going over 65mph! I'll get it, it just may take a while.

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I had a serious vibration at exactly 55 mph...after about half a year of just dealing with it I found it to be the steering box bolts were all loose..and one was missing! Don't overlook the small stuff.

Who would have thought???? I wouldn't have.

 

[747mopar]

O.K. might finally have an answer!!!!!!!!!!!! After everything has failed I set out to move the tranny up in the tunnel to better my angles but made one last call to Art Morrison (they surely know what works and what doesn't). After relaying my setup he says "your good to go, it's your driveshaft", I was taking it up that weekend anyways so just went ahead and took it there that day. I got the call the next day explaining that he had installed the wrong snap rings and that the shaft was balanced that way meaning it was way off, he said he balanced it down way beyond what it called for. If this does it I'll likely still try to raise the tranny to get some angle at the back just so the u joints last longer. Crossing my fingers.

 

[uwss]

Wow! Good job finding the issue. On Hwy 30 in Dallas, a dodge pickup driveshaft was ripped in half laying in the fast lane with about 4 cars damaged from hitting the pieces of the driveshaft. Ouch!!!

 

[747mopar]

Wow! Good job finding the issue. On Hwy 30 in Dallas, a dodge pickup driveshaft was ripped in half laying in the fast lane with about 4 cars damaged from hitting the pieces of the driveshaft. Ouch!!!

Let's not start saying good job yet, I still need to test it out! Got it back together but thanks to the endless rain my driveway needs allot of TLC before I can try it, maybe tomorrow.

 

[747mopar]

Finally got sick of waiting on the rain to stop and went puddle pounding today............. Now instead of vibrating at 60 mph it vibrates at 70 mph? Something that has me wondering is while talking to Art Morrison he said to make sure they spin the shaft up to 5,000 rpm, the shops machine only spins them to 500 rpm? These guys do driveshafts for racers all the time? Trying something different tomorrow

 

[hunt2elk]

What a nightmare Devin. At least the good news is that because the vibration changed with a driveshaft rebalance, I would think you have isolated the problem area.

 

[747mopar]

What a nightmare Devin. At least the good news is that because the vibration changed with a driveshaft rebalance, I would think you have isolated the problem area.

That's what I'm thinking although it's still possible that it's u joint angle related which is what I'm testing today. If I could find a professional shop that specializes in this sort of thing I'd gladly hand it over because I'm about out of ideas and fed up with it. Going to find another driveshaft shop if my test today comes up empty handed.

 

[747mopar]

ink banana: I got it finally!!!!!!!!!!!!!!!!! Damn U joint angles. I had shimmed the pinion up 1.5 degrees before thinking that would be correct (tranny 3 degrees down) because of axle wind up so today I tried it at 3 degrees up and voila. I kept going faster and faster and faster smiling with every 10 mph increase then pushed in the clutch at 90 mph and nothing but smooth coasting which where the worst vibration was (at coast). So now I have to figure out how to make this a driveable setup, with it shim 3 degrees up there's not enough room for the driveshaft so I either drop the motor, raise the tail of the tranny or modify the tunnel for more room? You may notice different angles mentioned throughout this thread that don't match, I am now measuring everything with the car levelled (sitting on it's weight in the rear), I started measuring the tranny off of the tail shaft, measure the pinion angle with the shaft removed and just got more picky about how I do it.

 

[mopar 3 B]

Been following this thread hoping you would find it. I have been fighting the same problem for years and after breaking several 727 tailshaft housing parked it. What are you now using to check angles with and at what locations are you checking them at?

 

[Dennis H]

Drive it. More. When it is dry. I want more confirmation. This angle schmangle doesn't sit. As said, my trans, shaft, motor was shoved in and is smooth. No measuring anything. No shims. Sustain 74 or so and kiss triple digits if safe.