Sure, but you do not mention which drive. If AQ series, I use the dip stick port for the gauge unit.
The drive must be drained of all gear oil for pressure leak down test.... negative pressure test doesn't care.
Good seals should hold 10 psi or so for hours without dropping.
Be sure to rotate the main drive gear, prop shaft and eccentric piston while under pressure.
The vacuum test will typically cause the single lip of the main drive gear seal to breach.
Not a deal breaker, just note that this type seal is not intended to hold against negative pressure in this direction.
You should be able to see 6-8 (
inHg) holding for hours.
If it were to drop some, but stop and hold, you're probably OK.
Again, rotate these shafts while under both positive and negative pressure to see if you can cause it to leak down.