The fact that it gets much worse when the drivetrain unloads, gives an indication that it is not just an unbalance in a wheel or motor, because those hadly suffer from the loading/unloading of the torque in the drivetrain from acceleration/deceleration. More likely it is related to the driveshaft or adjacent parts of the drivetrain, possibly halfshafts. One of the ways to test where the vibration might be coming from: - jack up the complete rear end (both wheels off the ground) - run the motor through its normal speeds in Neutral. If there is vibration then the flywheel balancing or transmission input is suspect. - run the motor at speed with the transmission in Drive, notice the speed of the vibration. - change jack to only lift a single rear wheel and run the motor at speed again - is there a difference in vibration? then it might be the half shaft else it is likely the driveshaft - change jack to only lift the other rear wheel and run the motor at speed again - is there a difference in vibration? then it might be the half shaft else it is likely the driveshaft - you can check for wheel unbalance (rear wheel that is) by removing the wheel at the latest tests to check if that makes the vibration go away.
BTW, some vehicles have a mid-driveshaft bearing that goes bad and causes vibration. Check the group discussions of your particular ICE vehicle to see if that is a common problem and how to diagnose & repair. Success. Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: cwa...@proxim.com Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -----Original Message----- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Michael Ross via EV Sent: Monday, June 09, 2014 1:27 PM To: Pestka, Dennis J; Electric Vehicle Discussion List Subject: Re: [EVDL] FW: Vibration Dennis, If it was any ICE car, where there is no DIY drive train stuff to distract one, I would ask them to check the tire balance once again. It is entirely possible a balance weight popped off. Or they forgot to balance one of them. I speak from experience here. At one time I used to refuse balancing as snake oil, but I learned better along the way. 65 Datsun means rear wheel drive, correct? A drive shaft is usually making clunky sounds going into reverse and back to forward if it is sick. CVs make clicking noises when turning if they are suspect. Is there any indication at all that the the motor and drive train are the cause? I presume they were fine at one time? If it was once smooth that sort of precludes any issues with motor/tranny/drive shaft/differential misalignments. Postponing them as a primary trouble shooting point. On Mon, Jun 9, 2014 at 3:55 PM, Pestka, Dennis J via EV <firstname.lastname@example.org> wrote: > The shocks are new, but I'll take a look. > > I don't know if this means anything, but let me repeat one thing. > Under acceleration with torque on the motor and drivetrain the vibration > is not too bad. Starts showing up ~ 55 mph. > When you let off the accelerator at that speed, the vibration gets very > bad and gradually goes away as the vehicle slows down to ~ 40 mph. > > Thanks; > Dennis > > > > -----Original Message----- > From: Jay Summet [mailto:j...@summet.com] > Sent: Monday, June 09, 2014 1:02 PM > To: Pestka, Dennis J; Electric Vehicle Discussion List > Subject: Re: [EVDL] Vibration > > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > One thing to check is your non-drivetrain elements, although if you get > the vibration without moving in neutral it's probably in the drivetrain. > > The reason I mention it is that our car had developed a vibration at the > 58-60 MPH speed range, and it turned out to be rear shocks that needed > replacing. > > Jay > > > On 06/09/2014 07:49 AM, Pestka, Dennis J via EV wrote: > > Removed the drive shaft, had new u-joints installed, and had it > > balanced. No change. > > > > I'm guessing it's either the angle on the motor/transmission in > > relation to the rear end, or I may have to pull the > > motor/flywheel/pressure plate/clutch assembly and have it balanced. > > When I sit in neutral and rev to ~ 3000rpm, I'm getting some > > vibration, although it doesn't seem to be as bad as when I drive. Here > > again I feel it at ~ 50 mph and up, but it is really noticeable when I > > let off the accelerator at those speeds. > > > > Thanks; Dennis Elsberry, MO http://www.evalbum.com/1366 > > http://evalbum.com/3715 > > > > > > > > > > > > From: Daniel Busby [mailto:busby.dan...@gmail.com] Sent: Tuesday, May > > 27, 2014 1:52 PM To: Pestka, Dennis J; Electric Vehicle Discussion > > List Subject: Re: [EVDL] Vibration > > > > I'd try balancing your driveshaft. It's relatively inexpensive once > > you get it out. A local place in LA costs less than $70. > > > > My '64 Spitfire definitely has a wobbly shaft, but I haven't made the > > time to pull it out and get it balanced yet. I stick to surface > > streets in the meantime. > > > > On Tue, May 27, 2014 at 11:29 AM, Pestka, Dennis J via EV > > <email@example.com<mailto:firstname.lastname@example.org>> wrote: Didn't know if > > anyone had any clues to a problem I'm having. > > > > Since I have my new Lithium pack, I've getting my 65 Datsun out on the > > highway and up to ~ 60 mph. Never did much of that before. When > > accelerating, I don't experience it, but when I let off the > > accelerator, I'm getting a pretty good vibration. Step back on the > > accelerator, and it goes away. Don't seem to notice it at 45mph and > > lower, but when going 55 - 60 mph. I just put new tires on it, and > > have had the front end aligned. > > > > Any suggestions ? > > > > > > Thanks; Dennis Elsberry, MO http://www.evalbum.com/1366 > > http://evalbum.com/3715 > > > > > > _______________________________________________ UNSUBSCRIBE: > > http://www.evdl.org/help/index.html#usub > > http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing > > discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) > > > > -------------- next part -------------- An HTML attachment was > > scrubbed... URL: > > <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140609/18 > > 6c7035/attachment.htm> > > > > > _______________________________________________ > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing > > discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) > > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.11 (GNU/Linux) > Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ > > iEYEARECAAYFAlOV9psACgkQSWJjSgPNbM88UACeP3S/O6WsfiKM9/e7OvGVDxxY > dywAnAmPcf3V/0v3S2PHpgyeu6JZp37f > =qiv8 > -----END PGP SIGNATURE----- > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, "The summer day." To invent, you need a good imagination and a pile of junk. Thomas A. Edison <http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html> A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com <michael.e.r...@gmail.com> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140609/a50e 962c/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)