Town Car vibration only in overdrive at 70+ mph

[Kotagami]

Hey Guys,

i have a fairly new problem (couple of months) with my Town Car. When im on the Autobahn at around 70 mph upwards a vibration starts going through the whole car, like an on/off (breathing) ßvibration. At first i thought it would be my worn out tires (now have new tires) but today i went on the Autobahn again and disabled overdrive while having the vibration and it was gone, when i enabled overdrive the vibration started again. So it has to be related to the transmission or am i wrong ?

looking forward for some answers and thoughts. thanks in advance.

 

[driller]

...disabled overdrive while having the vibration and it was gone, when i enabled overdrive the vibration started again.

NVH issues are difficult to isolate, especially so over the internet. Pure guess on my part, but I would say that indicates an issue with the OD band in the transmission?

 

[oktowncar]

Universal joints, transmission mounts, OD band as mentioned above could be the culprits to look at