[hotbird]

Got an 87 Thunderbird Sport, with the 302 and AOD trans. According to the previous owner, the trans was rebuilt to factory specs. It has the PRN(D)D1 quadrant, and in any gear except manual first, it has a valvebody buzz. Shifting to other positions changes the frequency of the sound, but it won't go away completely except as previously mentioned. And for some reason it will only do it occasionally, seemingly at random.

I know the 4R70W trans will do that if you mess with the EPC screw, what causes this in the AOD?

 

[SilverFox]

FORD designed a differnt VB gasket to solve this issue in 1989-90.
it is common, but not necesarily a problem.