I had a similar vibration in my '62 LeBaron last summer. It only happened at exactly 60 mph. It wasn't there below 60 or above 60. My front end man said it was the drive line and my transmission man said that it was the front end. I had the front end rebuilt, tires balanced, checked the front wheel bearings, replaced the transmission mount, u-joints, center support bearing and mount. Nothing made it go away. I didn't feel bad about doing all of that stuff to the car since it was all old and worn anyway. I did not have the drive shafts balanced. I knew that the vibration wasn't there before, so that wouldn't have changed. It turned out that one of the radial tires had something wrong with it. It was on the right front. I still don't know what was wrong with that tire. It was not out of round, it didn't have a "bend" in it, and it was in balance. I had all four tires balanced five times. It never felt like it was only emanating from the right front of the car. Out of desperation, I bought a new set of tires, and the entire problem went away. In addition, due to the fact that I had all of that other work done, the car drives better now than it has for the whole 25 years that I have owned it. Paul In a message dated 8/19/2004 9:47:27 PM Eastern Daylight Time, Kenyon Wills <imperialist1960@xxxxxxxxx> writes: >Phillipe. > >It is my guess that you took your car completely apart for the restoration. >If you did, then maybe you took your two driveshafts apart when you did? > >If so, did you mark them and re-assemble as they were when they came off the >car? > >They were balanced at the factory to go together one way, and only one way as >far as I know. �Is it possible that you re-assembled them in a different way >than originally? �Is this what you mean by "being inline with the O mark"? �I >am assuming that this is what you're talking about, but if not would be the >first thing to look at. > >If it is correct, I would look at balancing wheels first, as they should be >balanced anyway, and they are easy and cheap to do by comparison to the >driveshaft. � > >I will also assume that your driveshaft bearing isolator that holds the >driveshaft in a bearing in the middle is OK? �Check that by pulling and >pushing with light on it to inspect? �Probably not that. > >-Kenyon > > >Philippe Courant <accf-club@xxxxxxxxxxxxxxxx> wrote: >Hi, >As i worked under my car today, i checked the propeller shaft angles with a >"home made" tool. Since the beginning (2 1/2 years) i've a (not good !) >vibration, exactly between 40 and 45 mph (and another at 80 but i don't run >the car often at such speed). The vibration occurs every time i'm between the >two values, if i'm in accelaration or deceleration phases. >Itsn't a very hard vibration but it is noticeable so i think about two >problems (wheels are ok): >- unbalanced prop. shaft >- problem of working angles. >But FSM (and service reference books) are not very clear : i've measured the >two (rear) angles, what do you think of them ? ( >http://www.ifrance.com/accf-cad/imagfor/prop.jpg ). The service book says ( >http://www.imperialclub.com/Repair/Lit/Master/114/page13.htm �and other pages) >"not over 3� " ... Seems that i'm higher ! I've verified that the two prop. >shafts are "in line" with the "O" mark which is indeed rather not noticeable .. >Must install "tapered shims" ? Where i can find them ? Is these shims only a >"wedge" of 2� angle ? > >I think that i've rather an unbalanced prop. shaft condition but perhaps you >have some infos > >Thanks > >-- > >Philippe COURANT (Pau, France)- Webmaster des sites ACCF et C-I-F > >Imperial 1957 Crown convertible > >Buick 1996 Roadmaster wagon > > > >- American Car Club de France (ACCF) : http://www.accf.com > > > >- Chrysler Imperial France (C-I-F) : http://www.ifrance.com/c-i-f > > > >- Cadillac " Standard of Excellence " : http://www.ifrance.com/accf-cad > > > >- SportsCars : http://www.ifrance.com/accf-sprtcar > > > > >Kenyon Wills >http://imperialclub.com/Yr/1960/Kenyon/Page01.htm >http://imperialclub.com/Yr/1964/Kenyon64/ >http://imperialclub.com/Yr/1970/Kenyon1970/index.htm >http://imperialclub.com/Yr/1973/Wills/index.htm > > > > > > > > > > > > > > > > > > >