Here is the post from my vibration problem...
Rereading it, I think I was kinda freaked by finding out what holds the springs in, after the knuckle is off...
In the end, I had to replace the transmission; it probably died from the leak around the tailshaft, it causing a constant low fluid problem.
The u-joint was undetectable (by me) in the car; it was totally obvious when the shaft was out. Only one front bearing was toast.
I'd start with a detailed inspection of the driveshaft, off the car, if possible. While replacing it with a good unit, either 1-piece mark 8 or aftermarket, would be my personal recommendation...
I can't prove it, but I think the original cause of my whole vibration problem was the driveshaft itself failing, and from there the vibration took out the rear end, ujoint, and transmission tailshaft bushing.
This took about two years from the original onset of vibration. Transmission died last, as I said, and was probably preventable if I'd replaced the tailshaft bushing/seal sooner.
Good luck; Knowing what I know now, I'd track it down sooner than later.
Red '96 Cougar XR-7 240k mi. '02 4R70W, PST DS : '03 PI engine, 04 maf, 24lb injectors, 2.5" exhaust, '02 4r70w + Jmod, DirtyD0g TC + cooler + 3/8" lines, 255 walbro fp. Alpine system.
Black '96 Cougar XR-7 (Lazarus) 210k mi PI Intake, '02 4R70W, Jmod, PST DS, GrogTune, Konis, Mark LCA+Poly, racecougar Custom Engine Chain, and JL and racecougar Bracing.
Black '97 Tbird Limited Edition, '02 4R70W, 255 walbro, PST DS, PBR Brakes&SS lines, Toicko Blues & Springs, GrogTune.
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