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57-62 Mystery Vibration

Started by John Shumate #21509, October 10, 2007, 06:01:45 AM

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dadscad

John,

Please let us know how converting the rear section to a solid tube works out. I've been chasing the rumbling vibration in my 63 CDV since I've had it (17 Years). It definatley seems to be coming from the rear section of the unit. I've had success changing the intensity of the rumble by working on the rear section joints and center support bearing, but have not had satifying results.

I've got two DS for my car. One I bought from a DS shop that was supposed to be rebuilt and the original that I've had rebuilt and that I've personally rebuilt. both DS still have the rumble.

Good luck,
David
Enjoy The Ride,
David Thomas CLC #14765
1963 Coupe deVille

John Shumate #21509

Question: I believe that I could replace my rear draiveshaft (1958 Sixty Special) with one from a 1957 Sixty Special without modification. The Sixty Special shaft is longer than the DeVille or Series 62. Can any one verify that the shafts are interchangeable? The 1957 shaft is one piece, while the 1958 is two pieces. Thanks,
John Shumate
John Shumate CLC #21509

Roger Zimmermann

Quote from: John Shumate #21509 on January 10, 2008, 01:51:29 PM
Can any one verify that the shafts are interchangeable? The 1957 shaft is one piece, while the 1958 is two pieces. Thanks,
John Shumate
John, you are wrong: the '57 shaft is also in 2 pieces. According to the Master parts book, the '57 & '58 60S shafts are identical.
1956 Sedan de Ville (sold)
1956 Eldorado Biarritz
1957 Eldorado Brougham (sold)
1972 Coupe de Ville
2011 DTS
CLCMRC benefactor #101

The Tassie Devil(le)

You can't change the Two-piece Tailshaft to a One-piece as there will be total binding within the centre of the Chassis where it passes through.

And, you definitely don't want that.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe

John Shumate #21509

Quote from: The Tassie Devil(le) on January 11, 2008, 04:57:44 AM
You can't change the Two-piece Tailshaft to a One-piece as there will be total binding within the centre of the Chassis where it passes through.

And, you definitely don't want that.

Bruce. >:D
My statement was not clear. In 1957 the rear shaft (of two shafts) was a one-piece construction. In 1958 the rear shaft (of two shafts) was a two-piece construction. The '58 rear shaft is composed of two different diameter tubes. The smaller tube inserts inside the larger one, with a rubber cushion between the two. One yoke is attached to the smaller tube and one yoke is attached to the larger tube. Deterioratation of the rubber cushion permits harmonic vibration to amplify.
John
John Shumate CLC #21509

Roger Zimmermann

Quote from: John Shumate #21509 on January 11, 2008, 05:21:53 AM
My statement was not clear. In 1957 the rear shaft (of two shafts) was a one-piece construction. In 1958 the rear shaft (of two shafts) was a two-piece construction. The '58 rear shaft is composed of two different diameter tubes. The smaller tube inserts inside the larger one, with a rubber cushion between the two. One yoke is attached to the smaller tube and one yoke is attached to the larger tube. Deterioratation of the rubber cushion permits harmonic vibration to amplify.
John
It's more easy to understand put that way! Looking at the Master parts book from 1958 shows a different part number for 1957 and 1958 drive shafts. However, in a later parts book, there is only one part number for '57 & '58. It's possible that the rear shaft was one tube contruction in '57 and 2 concentric tubes in '58; the parts book does not say the differences.
On the other side, my '57 Brougham is equipped with a 2 concentric tubes shaft. Was the drive shaft replaced during the existence of the car is unknown.
Anyway, I have also some vibration / body boom at 65 miles/h (100 km/h). For 2 years, I removed the shaft, replaced the front joint and replaced the central support as I was not sure if the bearing was still good. The first test drive was a large disapointment: at the same speed, there was a lateral shake, worse than before! Then I began to think seriously at that matter. All joints were replaced when I restored the car; why, after a rather short mileage, the first one (near the transmission) was no more good? Then I remembered a statement made by a friend: when there is no relative movement in a joint, it get worn quickly.
As I'm not equiped to determine if the first shaft was exactly aligned with the transmission, I put some washers between the transmission's support and the frame. This simple action did wonders as the shake disappeared. Unfortunately, the body boom is still there...
1956 Sedan de Ville (sold)
1956 Eldorado Biarritz
1957 Eldorado Brougham (sold)
1972 Coupe de Ville
2011 DTS
CLCMRC benefactor #101

John Shumate #21509

Because the re-balancing of the rear shaft caused a significant reduction in the sound, I figured I was working on the right item. I determined that the 1957 rear shaft was a one-piece tube that would fit, so I got one and had it put in. The sound did not go away. The sound remains harmonic (volume increasing and decreasing). This debunks the idea that the 2-piece shaft was the root of the problem. I am now REALLY frustrated. The only thing I can think of to do is look for a dynamometer-and-pit combination, in which to chase it with a stethoscope.
John Shumate
CLC 21509
John Shumate CLC #21509

dadscad

John,

Thanks for the update, disapointing as it may be. I was hoping you would find the simple solution for a number of us dealing with the rumbling issue. The rubber in the sandwich has always been a question in my mind about the rumble.

In my 63 shop manual, it states, when the rear shaft section CV U-joints are defective, that the rear shaft section is to be replaced with a new factory assembled unit. Reason stated, the factory has special equipment that insures each cross joint is perfectly centered to the adjoining cross in the CV joint unit. Field repair is not possible without this special jig to insure alignment of the yoke, cross joints and drive shaft tube.

Following instructions from a 1970 Motors manual, I have disassembled my 63's rear section on numerous occasions, chasing this rumble. I've tried my best with my primitave shop tools, to get things centered as best I can, which did improve the situation on the last assembly I performed. The rumble is still there but not as severe as it was. I've put 20 or so thousand miles on the unit since that time and it has not changed since I re-installed the drive shaft.

One tip I'll offer if someone is going to do a CV joint repair. I learned, that the ball socket really needs the special lubricant sold for that purpose. I used regular chassis/wheel bearing grease one time and had to replace the ball socket parts in short order. The lube washed out and the ball socket started breaking up. Talk about an un-nerving noise!

David
Enjoy The Ride,
David Thomas CLC #14765
1963 Coupe deVille

Big Fins

An addition to the trouble and the cure;

I have a 1959 Sedan deVille, and the same rumble/noise/vibration we have all discussed. I pulled the shaft and took the unit to the local driveline center. The front joint was replaced as well as the center and rear joints and as was the carrier bearing.

$325 later the drive shaft still vibrated. Initially it was 20o out of phase, due to the rubber bushing being dried out and letting the 2 piece shaft spin within itself. I pulled it again and had it rebalanced. It was perfect.

The front shaft section is now in perfect alignment with the output shaft of the transmission using 1/4", flat washers as shims on the carrier bearing mount. These are flat washers for a 1/4" bolt, not 1/4" thick. I now keep the rear section of the car the same ride height as the front. Measured from the frame to the ground, both front and rear being equal. I had to help the rear up by using 1" coil spring boosters, twisted into the rear springs. Assisting the rear is also a set of Monroe Max Air, air shocks. I now have just the slightest harmonic vibration at exactly 60 MPH. Above or below this speed it is a dream to drive.

It took a lot of trial and error to find the "Sweet Spot", and what I have now is just fine.

Hope this helps,
Fins