I can only guess. The second and third problem with vibration. What type Overdrive. D or J?

Did you do anything to the OD before you installed everything???

If you did not change the actuating piston O-rings in either OD, or installed the wrong size or had the pistons in wrong or the bars down tight, before you installed everything, a blow by of fluid past them would not allow sufficient pressure to hold the sliding member in OD mode.

When this happens the sliding member slips, allowing the Sprag to catch in 4th which jerks, allowing pressure to build which jerks then repeats, which could be the vibration you indicate.

If the solenoid in the D is not properly adjusted, a similar low pressure can cause the same shudder. A partially blocked J solenoid can also cause the same.

Electrically, an intermittant connection somewhere after the switch could casue an ON-OFF-ON etc shudder but usually only in OD mode only and not lower gears unless the power is there all the time which it should not be.

Only guesses since your post does not give enough specific info to guess more accurately from afar.

Duane