If there are no shims on the center bearing support mounting, does this mean it is making the driveshaft sit too high in the car? Look at the angle from the side, underneath the car and see if the front part of the driveshaft seems to be on the same line as the back part. If it looks like it has to "bend" at the center support, that is part of your problem. The caution about balancing a brand new tire is an old one, which is valid only if the installer neglected to verify that the bead is completely seated against the rim, either by being very careful, or by neglecting to use a lubricating solution on the tires, so that it will seat itself as soon as it is inflated. I think this is grasping at straws, frankly, but have at it, if you want. Dick Benjamin ----- Original Message ----- From: Philippe COURANT <accf_clb@xxxxxxxxxxxxxxxx> To: <mailing-list@xxxxxxxxxxxxxxxx> Sent: Thursday, May 02, 2002 2:11 PM Subject: Re: IML: shudder on a '57 > Thanks Dick for your complete answer .. But before i'll do an > easy check: balancing the wheels and tires.. My tires were > balanced when i installed them new on wheels (600 miles since) > and someone tells me that the tires must not be balanced when > they are new and just installed but after some driving. > if i don't have any improvements i'll check the driveshaft and > U-joints angles. On '57 Imperial ther's two adjustements: > - at center bearings (shims under center driveshaft carrier; at > this time i have no shims) > - at forward end of struts springs with tapered shims (2° ? Where > i could find one !!) > Note that i don't notice this shudder before yesterday .. And i > haven't work on transmission since several months.. > > -- > Philippe COURANT (Pau, France) > Imperial 57 Crown convertible > Buick 58 Roadmaster sedan > > - American Car Club de France (ACCF) : http://www.accf.com > > - Chrysler Imperial France : http://www.ifrance.com/c-i-f > > - Cadillac " Standard of Excellence " : > http://www.ifrance.com/accf-cad > > - SportsCars : http://www.ifrance.com/accf-sprtcar > > > > > >