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S52/ZF320 Driveline Vibrations

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    S52/ZF320 Driveline Vibrations

    I am having bad driveline vibrations with an S52 swapped e30 on deceleration. I wish I had a video, but it sounds like the driveshaft or transmission is hitting the floorboard in a rhythmic fashion that is linked to the vehicle/engine speed. It does not happen while stationary. I can only replicate this when I accelerate, typically hard, then abruptly let off the throttle. To stop the vibration I usually speed up, slow down below ~30mph or press the clutch in. I have replaced just about everything in the driveline excluding the differential, engine and trans. The parts I have replaced in the last few months are as follows:
    - Revshift 80a 24v swap mounts
    - Garagistic 80a trans mounts
    - New Meyle Guibo
    - New aftermarket OEM replacement driveshaft with new CSB
    - 3.07 LSD from e28
    - 80a subframe, diff and trailing arm mounts
    - stock untouched e30 axles and wheel bearings

    I started the swap with the engine and trans mounts. I had a new CSB on the old driveshaft. The issue was observed before and after the replacement of the Guibo, driveshaft, and subframe mounts. Yes I have preloaded the CSB and installed the driveshaft per various manuals.

    I called Revshift and they pointed to the trans mounts, so I decided to order new ones as I have been told a studded design is better than through bolt. They told me the trans mounts were roughly 1.3" and I measured the mounts to be roughly 1.25". I also noticed the driveshaft is pointed down in the CSB from the front of the car looking back.

    This has been driving me crazy and I cannot figure out what the issue is
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    #2
    This was taken in my 1990 BMW 325i. The knocking noise heard in the video is an absolutely trashed CSB. If your car sounds like this, the CSB will need to be...


    It sounds similar to this video at roughly 50 seconds, but a little deeper sounding and it keeps happening until i press the clutch in or start accelerating again.

    Comment


      #3
      Have you looked for any areas where the drive shaft could have possibly contacted the car? Can it be replicated with the car on jackstands?

      Comment


        #4
        Originally posted by jbontke View Post
        Have you looked for any areas where the drive shaft could have possibly contacted the car? Can it be replicated with the car on jackstands?
        I haven't been able to see any marks on the DS or in the trans tunnel. I was going to remove the heat shield and run it on jack stands to check for any weird vibrations or misalignments with the driveshaft.

        Comment


          #5
          Is your exhaust snug?

          Comment


            #6
            Originally posted by jbontke View Post
            Is your exhaust snug?
            I believe it is. I had the m3 exhaust poorly welded onto the e30 cat back to get the car moving. It did it when I had this exhaust and when I rebuilt the exhaust.

            Comment


              #7
              Does depressing the clutch cause any change in the vibration?

              Comment


                #8
                Originally posted by jbontke View Post
                Does depressing the clutch cause any change in the vibration?
                Typically when it is vibrating pressing the clutch causes them to immediately stop

                Comment


                  #9
                  Originally posted by cdl723 View Post

                  Typically when it is vibrating pressing the clutch causes them to immediately stop
                  What is your clutch, flywheel, throw-out bearing setup?

                  Comment


                    #10
                    I'd double check the CSB
                    Originally posted by priapism
                    My girl don't know shit, but she bakes a mean cupcake.
                    Originally posted by shameson
                    Usually it's best not to know how much money you have into your e30

                    Comment


                      #11
                      Originally posted by Northern View Post
                      I'd double check the CSB
                      The CSB looks alright. The old driveshaft had a new CSB and the new driveshaft has a different new CSB. I preloaded it and all correctly as well

                      Comment


                        #12
                        Have you watched it in motion?

                        Use good jackstands, and see what you can see as it spins.

                        I've found bent diff flanges, loose pinion bearings, and a bent transmission
                        output shaft this way.

                        Yes, it's a little unsettling- I suppose you could stuff a few small video cameras down
                        there, but that would be cheating.

                        t
                        now, sometimes I just mess with people. It's more entertaining that way. george graves

                        Comment


                          #13
                          Originally posted by TobyB View Post
                          Have you watched it in motion?

                          Use good jackstands, and see what you can see as it spins.

                          I've found bent diff flanges, loose pinion bearings, and a bent transmission
                          output shaft this way.

                          Yes, it's a little unsettling- I suppose you could stuff a few small video cameras down
                          there, but that would be cheating.

                          t
                          I just got some time to get under there. I could not see anything underneath the car other than a video looking right at the CSB it looks like there might be some vibrations, but cant tell where. When I was in the driver seat and hit the gas/let out the clutch I felt some vibrations, but they were not nearly as harsh as the ones that initiated this search. I believe the sound in the video is some rust on the brakes resulting in a rhythmic noise, but this is not the one that concerns me.

                          Please take a look at this google drive and let me know where you all think this is coming from.



                          Also I used my phone with an angle app and measured a few degrees difference between the crank harmonic balancer and the front half of the driveshaft. I am guessing these couple of degrees might be my issue. I also measured the front and rear shafts and they were roughly 1-2 degrees off from one another.

                          Comment


                            #14
                            I watched the videos, nothing stands out besides the noise in the rear. The rear axles were the same before the swap (assuming no vibrations). Were there vibration issues with the old diff? Is the Diff cover bushing new/old?

                            On another note, drive line phasing can cause vibration. I had a vibration at 80 mph in my e30. Replaced the motor mounts and it went away. The engine was nose down. Got me thinking about the issue. My driveline only posed an issue at 80 mph, whether I was on throttle, cruising, or off throttle. But you are getting an issue on hard load/unload of the drivetrain. You wont be able to replicate that on jack stands. Got a Go Pro? It would be interesting to watch the diff during this.

                            Comment


                              #15
                              New diff bushing. I didn't imagine i would find much because its an off throttle issue that seemed like it needed a load for. Im pretty sure the noise in the rear was the brake rotors having rust on them... Or maybe my parking brake shoes falling apart(it stopped working). Unfortunately i do not have a GoPro. I ordered a set of revshift trans mounts to see if this will solve my issues.

                              I drove it around to replicate it again and the vibrations were not as loud, but they still occurred only off throttle. Im wondering if it's worth loosening and retightening the engine trans and driveline mounts to get the rest of the vibrations out.

                              Comment

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