1939 Buick Driveline Vibration Question

[BuickBob49]

I purchased David Corbin's 1939 Roadmaster last fall through Pete P.  It is a great car with some history.  I've added it to my 1949 Super 51, which I've had since 1978.

 

My mechanic and I replaced the clutch, rebuilt the brakes, and sorted out some electrical issues.  I replaced the tires this year with Coker radials.  The cluster gear and 1st/reverse sliding gear in the transmission are worn and should be replaced.

 

My real problem is that I have a vibration in the drivetrain at high idle.  It is also noticeable going down the road at higher rpms in lower gears and above 40 mph in 3rd. The vibration goes away when coasting in neutral at 40+.  Could it be an out of balance pressure plate or something else?

 

1939 Model 81

Style No. 39-4819

Body No. 2305

Trim No. 718

Paint No. 530

Body No. 13467033

Engine No. 83629265

[Terry Stock]

Mine had a vibration at 50 mph which new engine mounts fixed.

[1939_Buick]

As above, check the engine mounts and the rubber torque ball mounts at the transmission. Everything needs to be alignment and in good condition. But it could be something else.

 

(Would have better to start a new thread on the problem:- more exposure with a descriptive thread title)

[MCHinson]

I have moved this to a new discussion. Hopefully it will get more attention in a new discussion.

[danhar1960]

G'day "BuickBob49".

Driveline vibrations could be many things.

Was the vibration there before you changed the clutch ??

I'm not up on 80-90 series but I think they don't have the short shaft of the smaller models.

As Al (1939_Buick) says, the engine and transmission mounts would be the first thing I'd check.

I've found that with a little oil on them, the old rubber turns to jelly.

I assume the universal joint was checked when you had it apart.

Did you have the transmission apart or just look in with the top off ??

It's a bit hard to say much more without actually being in the car.

 

Danny