1960s 62 Sedan DeVille Mystery Driveline Vibration

[Adam Martin]

Hello all, I am dealing with a vibration that has my head spinning.  I am used to dealing with Buicks with the center carrier bearing on the driveshaft, and that is what is wrong 90% of the time on those.

Initially, I felt this vibration and immediately pulled the driveshaft to have the carrier bearing replaced and also had the driveshaft balanced at that point.  I have also replaced all wheel bearings front and back.  Brand new tires from Diamond Back.  All drums turned.

Is there a way that the transmission can be incorrectly mounted to the engine where it causes a high frequency vibration?  We have to deal with this in Buicks with the Dynaflow, and if the flex plate is clocked wrong on the torque convertor, it will cause a similar vibration. 

Transmission mount is brand new, and engine mounts are good and tight.

Unrelated - do these Hydramatic transmissions whine a lot while in neutral?  This one sings pretty loudly when not in gear.

Thanks!

Adam

[Adam Martin]

I should mention that it is most prevalent at 25-40 mph.

[TJ Hopland]

How long have you had this car or has it been under your care?  And has it always had this vibration or did it suddenly or slowly start?  Were you chasing other issues replacing all those parts or was that all for the vibration?

[Adam Martin]

It came to me as a running project, so I never had it on the road until I had brakes, carb, etc worked out.  So it has been there the whole time I've had it here for the last couple months.

[klinebau]

Driveline angle might play a role.  I remember seeing a few threads that discussed shims for the center carrier bearing.

[Adam Martin]

Ah ok...I recall seeing what appeared to be a 1/16" shim under the carrier bearing when it was removed.  I'll look to see if that made it back in.

[Clewisiii]

Because I like pictures. I believe there were shims both for the trans and the bearing if needed. I was a little puzzled with the placement of the trans shims.

[60eldo]

  What does flex plate being clocked mean. Im getting my engine rebiult and when it gets back do I need to do this?  I thought just lower the engine in and match 4 bolts to the studs on the torque converter.

[Dave Shepherd]

Drive the car, when you feel the vibration, shut the engine off, put it in neutral, see if you feel the vibration. What you descibe is usually a driveline issue.

[Adam Martin]

Ok...I did find the section in the manual about adjusting vertical and horizontal placement of the trans/rear/driveshaft.  Without those special brackets and tools, how does one check this stuff?  Should I start with a shim under the carrier bearing and go from there?

RE:  clocking of the flex plate - Buicks of this generation use a kind of triangular flex plate that can be clocked incorrectly on the torque convertor, causing a vibration very similar to what I am describing with the Cadillac.  At this point, I don't think that is an issue on this car.  I think we are onto something with the shim situation, though.  I just have to figure out how to take the measurements without the goofy kent moore tools.

[60eldo]

 Mine is a 1960, I think its the same as yours.

[Adam Martin]

I did some digging...and found this old thread....lots of good info about the mysterious kent moore tools that cannot be found to actually do this job...

https://forums.cadillaclasalle.club/index.php?topic=68680.0

[The Tassie Devil(le)]

One think I did find with my '60 CDV, was that the upper ball joint on the top of the differential (Rear upper Control Arm) that controls the vertical and sideways movement was totally trashed.

This part of the car would have to be the least seen or checked, as it is up ant out of casual eyesight.

Bruce.

[Clewisiii]

One think I did find with my '60 CDV, was that the upper ball joint on the top of the differential (Rear upper Control Arm) that controls the vertical and sideways movement was totally trashed.

This part of the car would have to be the least seen or checked, as it is up ant out of casual eyesight.

Bruce.

And those are expensive.

[Carfreak]

Anyone remember Robert Reeve from Lansing Michigan?  He had a 1959 SDV that he drove all over the country to attend GNs often pulling a trailer. 

He had annoying driveline vibration that drove him nuts. Finally after checking and replacing many parts, I think he found it was a defective harmonic balancer.

[Adam Martin]

Ok, I have shimmed 5/8" of shims under the transmission mount, and the vibration is slowly disappearing...but 5/8" seems excessive.  I think I was sent the wrong height carrier bearing.

Here is the one that is installed...it is tall.

https://www.ebay.com/itm/284785319769

There is also this one, which is much shorter....which one is really correct?

https://www.ebay.com/itm/153738247417

[Adam Martin]

Talking to Jay at caddy daddy and I think I was sent a 63-65 canter support piece.  I just ordered a correct one from him.  I really hope this alleviates the issue.

[Adam Martin]

The new support came from Caddy Daddy over the weekend.  Comparing the one I have installed to this one, I can see the new one has a slightly different pitch than the one that is installed.  So it could easily explain why I had to shim the transmission up so much to make it go away.  Both supports are the same exact height, and appear to be identical housings....but the rubber piece that is vulcanized onto it is at a different angle.  I hope this fixes it.

[Adam Martin]

Vibration is virtually gone now.  I still might experiment with some shimming to try and get it perfect. 

This has been.....fun.