Oscillating Vibration in a 58

[lmhnm]

Hi, I'm new to this forum and actually x frame cars. I have a 58 sedan with a slight shudder at takeoff, and an oscillating vibrations at all speeds. I can't find it, so I thought I'd ask the x frame experts. The car has a later model 350 with a turbo 350 trans, original rear. I've tried the following with no luck: rebuilt the driveshaft with new center bearing & u-joints twice, rebalanced once. Changed a tired 283 with the new 350. New flex plate & torque converter. New wheel bearings, new wheels & tires. I have not changed the tranny or gone into the rear yet, hard for me to believe they would cause it. I need to cure this soon, as I'm planning on a lot of travel this summer, and even though it doesn't seem to hurt anything, it irritates me all the time! Any suggestions out there?

[bobs409]

Imhnm,

Welcome to the site. Most likely it's the drive shaft angles out of adjustment. They have to be set by adding or removing shims under the trans and the center bearing.

The shop manuals tell how to do this and what to set them too or maybe someone here can give more details on it.

[fatride]

Check your pinnion angle, stock pinnion angle for these cars are around -4 dgs.