Lincoln/Mercury Repair: Transmission, spark plug wire, gas struts

Question
1996 Towncar with 44,000 miles.
While driving the car seems like a rumbling sound coming from the rear of the car, usuall right before it shift, seems like it might be transmission, its not slipping or anything that seems like transmission trouble but have a funny feeling it might be trans, also the rear air-suspension bags were replaced with gas struts. Thought if this might also have something to do with the sound and rumbling?

Answer
Hi Rudy,
Part 1:
Does this happen at about 45 mph? If it does then it is the famous converter chatter. Your auto parts store will sell a product that will fix this. Just ask for transmission anti chatter additive for Fords. There was a recall on this or at least a TSB Technical Service Bulletin years ago. I tried to find you a link but I couldn't. The recall may be over. This chatter happens when the torque converter goes into "lock-up" usually around 45 mph.

Part 2: If this isn't just at 45 mph then it could be a bad spark plug wire. One of the ones towards the firewall could be shorting out on the firewall. I know, sounds crazy, but it is a common thing to happen! A tune up will solve this issue! Hope this helps!