Bad vibration over 60 mph

Engine, Trans & Driveline

  1. Street fighter

    Street fighter Well-Known Member

    Messages:
    107
    Likes Received:
    9
    Joined:
    Aug 5, 2013
    Location:
    Vicksburg,Miss.
    Local Time:
    8:53 PM
    I have a 73 charger that have a bad vibration at about 6o mph I have replaced rear tires after being told by two places that one of my rear tires had a flat spot on it, when I say a vibration I really mean a vibration that can be felt more when you get off the gas,I have what looks like some kind of a balancer on the rear of the trans that have two bolts that mounts to the trans, I noticed that the two rubber bushens are just about gone ,could this be my problem? I plan to check weight on the convertor and the balancer on the engine. what else could it be? also I will be checking the drive shaft weights. The engine is a 360 NEED HELP.
     
  2. Dennis H

    Dennis H FBBO Gold Member FBBO Gold Member

    Messages:
    10,783
    Likes Received:
    11211
    Joined:
    Jul 11, 2010
    Location:
    San Jose
    Local Time:
    8:53 PM
    Can you shut it off at speed. Veer left right. Pop into neutral etc. Put someone in trunk.
     
    • Agree Agree x 1
    • BeepBeepRR

      BeepBeepRR Well-Known Member

      My Photo Garage
      Messages:
      2,090
      Likes Received:
      1871
      Joined:
      Oct 16, 2016
      Location:
      Atlanta,Ga
      Local Time:
      9:53 PM
      Is this on the transmission itself or on the drive shaft? Does it look like this? If it looks like the one in this picture its a parking brake.

      IMG_1395.JPG
       
      • Agree Agree x 1
      • 68gtxman

        68gtxman FBBO Gold Member FBBO Gold Member

        My Photo Garage
        Messages:
        1,569
        Likes Received:
        3396
        Joined:
        Aug 23, 2011
        Location:
        Eastampton, NJ
        Local Time:
        9:53 PM
        Rear pinion angle out of spec can do this. Search for threads on this and you’ll find an easy way to check it on your car. Good luck!
         
        • Agree Agree x 2
        • khryslerkid

          khryslerkid FBBO Gold Member FBBO Gold Member

          My Photo Garage
          Messages:
          15,626
          Likes Received:
          20491
          Joined:
          Mar 10, 2010
          Location:
          Hanover, Pennslyvania
          Local Time:
          9:53 PM
          Maybe transmission mount? If it's bad it could definitely cause a vibration.
           
          • Agree Agree x 2
          • Street fighter

            Street fighter Well-Known Member

            Messages:
            107
            Likes Received:
            9
            Joined:
            Aug 5, 2013
            Location:
            Vicksburg,Miss.
            Local Time:
            8:53 PM
            No it's not anything like that. it bolts on the tail of the trans and it have two 5/16 bolts that bolts it to the tail of the trans, each bolt is surrounded by two rubber bushings, it appears to be a counter weight for the tail of the trans to stop vibration.
             
          • dryheat

            dryheat FBBO Gold Member FBBO Gold Member

            My Photo Garage
            Messages:
            719
            Likes Received:
            344
            Joined:
            Feb 4, 2011
            Location:
            Glendale, AZ 85308
            Local Time:
            7:53 PM
            Please post a picture so we can see what you are referring to.
             
            • Agree Agree x 1
            • Bill Monk

              Bill Monk FBBO Gold Member FBBO Gold Member

              My Photo Garage
              Messages:
              1,597
              Likes Received:
              1627
              Joined:
              Feb 27, 2017
              Location:
              West Virginia
              Local Time:
              9:53 PM
              360s are externally balanced so it's possible you have the wrong balancer or converter but I doubt it from your description because I think you would feel that throughout the rpm range. Vibration problems are really hard to diagnose. Mounts, tires and wheels, worn out front end parts, driveshaft, pinion angle all come into question. Process of elimination. Good luck!
               
            • khryslerkid

              khryslerkid FBBO Gold Member FBBO Gold Member

              My Photo Garage
              Messages:
              15,626
              Likes Received:
              20491
              Joined:
              Mar 10, 2010
              Location:
              Hanover, Pennslyvania
              Local Time:
              9:53 PM
              If the counterweight is loose, flopping around, it needs to be solid to do it's job. See if you can replace the worn out rubber.
               
              • Agree Agree x 1
              • Street fighter

                Street fighter Well-Known Member

                Messages:
                107
                Likes Received:
                9
                Joined:
                Aug 5, 2013
                Location:
                Vicksburg,Miss.
                Local Time:
                8:53 PM
                It's not the trans mount it appears to be a counter weight to keep down vibration.
                 
              • Street fighter

                Street fighter Well-Known Member

                Messages:
                107
                Likes Received:
                9
                Joined:
                Aug 5, 2013
                Location:
                Vicksburg,Miss.
                Local Time:
                8:53 PM
                 
              • furyus

                furyus Well-Known Member

                Messages:
                1,223
                Likes Received:
                678
                Joined:
                Jan 5, 2010
                Location:
                weeki wachee, florida
                Local Time:
                9:53 PM
                It's very common for someone to put the wrong converter behind an externally balanced engine like the 360. That part you're talking about is a vibration damper. I've seen them before. First, you have to know when it's vibrating. Will it vibrate in park if you bring the rpms up? If so, the problem is in the engine/trans/converter. I have had converters fail internally, causing a vibration. Driveshafts have an oscillating rumble sound. Wheels and tires are more of a shake that you can almost feel each wobble. Check the trans mount. If it's bushings are gone, that could cause it.
                 
                • Agree Agree x 1
                • Street fighter

                  Street fighter Well-Known Member

                  Messages:
                  107
                  Likes Received:
                  9
                  Joined:
                  Aug 5, 2013
                  Location:
                  Vicksburg,Miss.
                  Local Time:
                  8:53 PM
                  Everything on the car is correct I have had it 30 years so I know it's none of those,I have a list of things that I am going to check and I hope that I can find out what's wrong, this can take some time the vibration is not coming from the front end steers great but you can feel it coming from the rear over 60 and slowing down from 60. BAD
                   
                • Street fighter

                  Street fighter Well-Known Member

                  Messages:
                  107
                  Likes Received:
                  9
                  Joined:
                  Aug 5, 2013
                  Location:
                  Vicksburg,Miss.
                  Local Time:
                  8:53 PM
                  I am going to try running it in park and check it. and see what I find ,I thought about the convertor so I checked the trans and there is no metal in it.
                   
                • 68Moparmaniac

                  68Moparmaniac Well-Known Member

                  My Photo Garage
                  Messages:
                  97
                  Likes Received:
                  158
                  Joined:
                  Jan 18, 2019
                  Location:
                  Utah
                  Local Time:
                  7:53 PM
                  So let me see, the car was okay before but now it's got a vibration? Replace any driveline parts recently? Slap any curbs (not like that ever happens). Could be something simple like your driveshaft shucked a counter weight, U-joints taking a crap, or wheel weight shifted/fell off, maybe the slip yoke is giving up. If motor mounts and/or trans. mount are toast that can also give you grief. I'd start with the least expensive stuff first before I ripped into it. My 2 cents
                  Best of luck :thumbsup:
                   
                  Last edited: Feb 15, 2019 at 9:32 AM
                  • Like Like x 1
                  • Agree Agree x 1
                  • bigbluedodge

                    bigbluedodge Active Member

                    Messages:
                    32
                    Likes Received:
                    17
                    Joined:
                    Aug 15, 2008
                    Location:
                    North Branch, MI
                    Local Time:
                    8:53 PM
                    I think if it was me I would remove the driveshaft to check the U joints for wear or one that's froze up.

                    Both my 73 Chargers had that cast weight bolted to the back of the trans. Even on the car I drove on the street (73 SE) I didn't notice the difference when I removed it.

                    Bryand
                     
                  • davek

                    davek FBBO Gold Member FBBO Gold Member

                    Messages:
                    1,213
                    Likes Received:
                    779
                    Joined:
                    Oct 14, 2017
                    Location:
                    columbia
                    Local Time:
                    9:53 PM
                    I would start with the drive shaft and go from there. you said it vibrates at 60 ,is that only when your accelerating or coasting ,did you put it in neutral to see if it would stop? So this is something new since you have had the car for 30 years. What did you change lately?
                     
                  • BeepBeepRR

                    BeepBeepRR Well-Known Member

                    My Photo Garage
                    Messages:
                    2,090
                    Likes Received:
                    1871
                    Joined:
                    Oct 16, 2016
                    Location:
                    Atlanta,Ga
                    Local Time:
                    9:53 PM
                    Anyone mentioned U-joints? My buddy had a bad trans mount and it caused the ujoint to wear out real fast. Had to replace both u-joints and a new trans mount. Fixed his vibration issue.
                     
                  • tonysrt

                    tonysrt Well-Known Member

                    Messages:
                    181
                    Likes Received:
                    140
                    Joined:
                    Dec 6, 2017
                    Location:
                    Northport, NY
                    Local Time:
                    9:53 PM
                    I just removed a 904 from my 74 Duster and I have that exact piece at the rear of the tranny that you have. I've put in a 727 and it doesn't have it. I looked in several books and there is no mention of that piece or even a picture of it on any trans. How about rotating tires front to rear to see if the vibration is now in the front. Do you drive car on a regular basis? Flat spots in tires happen from cars sitting for a period of time. Some tires are worse than others with flat spot problems.
                     
                  • 68Moparmaniac

                    68Moparmaniac Well-Known Member

                    My Photo Garage
                    Messages:
                    97
                    Likes Received:
                    158
                    Joined:
                    Jan 18, 2019
                    Location:
                    Utah
                    Local Time:
                    7:53 PM
                    First thing I’d do is crawl under the car and give either end of the drive shaft a good shake. If you get a bunch if shake at the rear it’s either the u-joints or your pinion bearings are going south. If it’s up front it’s either the u-joints or your slip yoke is shot. If everything seams tight it’s a good chance it’s mounts.
                     
                  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
                    By continuing to use this site, you are consenting to our use of cookies.
                    Dismiss Notice