vibrating at 2000 rpms sitting still.

Street fighter · Dec 16, 2019

I have a 73 charger with a 360 in it and It has a bad vibration sitting still at 2000 rpms and while driving at 70 mph. I have checked convertor to make sure weights are still on converter removed bolts from converter and hear some noise when I rotate it,can also hear a light noise while it is running sitting .what can it be? all new tires and it was doing it before the tires were put on.I know the tires would not cause it to vibrate sitting still but just wanted to let it known it has new tires on it.

Lefty71 · Dec 16, 2019

Hear some noise when?? Rotating the motor by hand? Or the the converter by hand when loose from the motor??

Scraping noise? or more like clicking?

Do you know the stall speed for the converter? Tried a stall test?

Don Frelier · Dec 16, 2019

Probably a few broken fins inside the converter.

Curiousyellow71 · Dec 16, 2019

Maybe a bad clutch fan? Dampener problem? Loose flex plate bolts at the crank or at converter...should be easy enough 2 check...bad converter may be tougher to diagnose. Possibly describe your light noise or post a vid.
Could be something different causing it to vibrate at 70...maybe its not related...perhaps it is???

Ceedawg · Dec 16, 2019

Let me know what you find out, a buddy has the same problem, we never thought of converter problem.

Street fighter · Dec 16, 2019

Lefty71 said:
Hear some noise when?? Rotating the motor by hand? Or the the converter by hand when loose from the motor??

Scraping noise? or more like clicking?

Do you know the stall speed for the converter? Tried a stall test?

with bolts out of the convertor turning convertor by hand I can hear some noise it may be normal but I can hear it. The engine have a small crane cam in it 272 with a 2200-2400 stall .

Street fighter · Dec 16, 2019

Lefty71 said:
Hear some noise when?? Rotating the motor by hand? Or the the converter by hand when loose from the motor??

Scraping noise? or more like clicking?

Do you know the stall speed for the converter? Tried a stall test?

more like clicking, stall is 2000-2400 all is done with converter loose from engine. how do you do a stall test?

1 Wild R/T · Dec 16, 2019

Is the vibration new? Or was it there when you bought the car? Has anything been changed?

Try running the engine briefly with the belts removed....

Noise in the convertor doesn't sound normal, the stator & impeller can rattle when the convertor isn't installed but when it's installer they are supported & shouldn't rattle....

Street fighter · Dec 16, 2019

Curiousyellow71 said:
Maybe a bad clutch fan? Dampener problem? Loose flex plate bolts at the crank or at converter...should be easy enough 2 check...bad converter may be tougher to diagnose. Possibly describe your light noise or post a vid.
Could be something different causing it to vibrate at 70...maybe its not related...perhaps it is???

I was thinking about checking the Dampener because it has been on this engine since 1980. the noise I hear is like it's out of balance when you stand in front of the car makes a bumping noise.

Lefty71 · Dec 16, 2019

Checking the damper is easy. Just remove the plug on #1 cylinder and use a tool to determine top dead center (any blunt object that will fit will suffice). Find top dead center and then look for the -0- mark on the damper.
Clicking in the converter likely means it could be self destructing and very well could be your vibration. Stall speed is tested by warming up the car and the trans, then lock the brakes and stomp the gas for about 5 seconds tops. Have a tach hooked up, which you will be watching, and don't let anything be in front of you, more importantly, anyone. Stall speed is supposed to be as high as it the motor can push it until it wont rev any higher. If the stall speed is way off one way or other, then it needs to be cut apart by someone who can rebuild it (preferably the manufacturer) and checked.

BB BELLA · Dec 17, 2019

deteriorating rubber can make a damper sound like the engines coming apart! It doesn't have to have spun. I've changed a couple on chev 6.5td's that people were scrapping the motor because of the noise, new damper fixed it!

Lefty71 · Dec 17, 2019

BB BELLA said:
deteriorating rubber can make a damper sound like the engines coming apart! It doesn't have to have spun.

I've not heard of this. I have heard that Fluidampers, which were once touted as the best, and the way to go when going racing, can be a problem. The fluid can get gooey, and if the car sits for an extended period of time (like way more than overwinter), the damper can become effectively ruined as the motor will be and will remain "out of balance" when you start using it again.

BB BELLA · Dec 17, 2019

I hate using stuff you can't see with the naked eye [fluid damper would be one of them,very hard to see a problem until too late} like beads in tires for balance, all it takes is airing up the tire without a drier on the line and the beads become a frozen block in winter!

dvw · Dec 17, 2019

Im assuming it's been together for some time with no issue? Is something touching the floor, cradle, frame? Headers, exhaust, collapsed motor, or trans mount? I doubt that the converter is causing the issue with no drivability issues. Slipped balancer is a possibility. So is a broken crankshaft, though both unlikely. Now if it's a new build. My bet is it has a converter with incorrect balance. From a 400, cast crank 440, etc.
Doug

Curiousyellow71 · Dec 17, 2019

Does the converter have a big triangular weight on the front of it for the 360? Just asking since you were spinning the converter recently and listening for noises.

Street fighter · Dec 17, 2019

Curiousyellow71 said:
Does the converter have a big triangular weight on the front of it for the 360? Just asking since you were spinning the converter recently and listening for noises.

The trans have two weights on the front of the converter I have tried to correct this issue for a year or more, I drive it get pissed and park it,the car looks great a eye catcher and gets a lot of nice car, but I don't want to keep driving it knowing it has this problem, I need to get this car fixed, I am going to try everything posted and see what I come up with thanks to all.

Street fighter · Dec 17, 2019

dvw said:
Im assuming it's been together for some time with no issue? Is something touching the floor, cradle, frame? Headers, exhaust, collapsed motor, or trans mount? I doubt that the converter is causing the issue with no drivability issues. Slipped balancer is a possibility. So is a broken crankshaft, though both unlikely. Now if it's a new build. My bet is it has a converter with incorrect balance. From a 400, cast crank 440, etc.
Doug

I have had the car for thirty years everything under the car but the headers is new and I plan to replace them after Christmas as a gift to myself. the engine was rebuilt about ten years ago and have about 4000 miles on it if that. the 360 have been in it with no problems since rebuild.

Curiousyellow71 · Dec 17, 2019

Street fighter said:
I have had the car for thirty years everything under the car but the headers is new and I plan to replace them after Christmas as a gift to myself. the engine was rebuilt about ten years ago and have about 4000 miles on it if that. the 360 have been in it with no problems since rebuild.

That helps clear that up. Obviously something has given up. Is it a aftermarket converter? It sounds like it's not original... most the oem 360 converters have one big weight...vs 2 smaller ones....But I could be wrong? Certain aftermarket brands have had issues with a vane coming loose causing a vibration. If it is a higher stall...they have to take more abuse then say a stock one. I think some of lower priced converters don't have the vains held on any better then a oem low stall unit...but yet it has to take the extra torque...the vain starts cracking and then comes completely loose causing a noise and a vibration.
The damper can cause a vibration...But it's a long shot unless the rubber is shot. You could apply light pressure on the damper and make sure nothing is loose.. If it's a fluid damper you visibly can not tell if they are bad...buy they can cause A LOT of grief if they go bad. If it has clutch fan...they can cause a vibration....loosening the fan belt like mentioned is easy enough to rule that out.

Street fighter · Dec 18, 2019

Curiousyellow71 said:
That helps clear that up. Obviously something has given up. Is it a aftermarket converter? It sounds like it's not original... most the oem 360 converters have one big weight...vs 2 smaller ones....But I could be wrong? Certain aftermarket brands have had issues with a vane coming loose causing a vibration. If it is a higher stall...they have to take more abuse then say a stock one. I think some of lower priced converters don't have the vains held on any better then a oem low stall unit...but yet it has to take the extra torque...the vain starts cracking and then comes completely loose causing a noise and a vibration.
The damper can cause a vibration...But it's a long shot unless the rubber is shot. You could apply light pressure on the damper and make sure nothing is loose.. If it's a fluid damper you visibly can not tell if they are bad...buy they can cause A LOT of grief if they go bad. If it has clutch fan...they can cause a vibration....loosening the fan belt like mentioned is easy enough to rule that out.

I have removed all the fan belts and still gets the vibration which is why I believe it's in the converter I hate spending money on a guess, I don't have much of a choice if it's in the converter the only way to know is to install a new one and pray that's it.I have replaced so much under the bottom section that it's hard to say what could be causing the problem. I am going to check the damper and if I don't fine anything I am going to get a new converter. I will post what I end up doing.This just come to me years ago when I installed the converter I was sent one without a weight on it and it did just what this one is doing.May be it is bad and out of balance. wish me luck thanks.

furyus · Dec 18, 2019

Also look at the flex plate. Is it stock Mopar, or aftermarket? The aftermarket ones come with different balance for each application. This is so you can run any converter without weights.

vibrating at 2000 rpms sitting still.

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