I have a 07 v-6 mustang I upgraded to a 3:73 rear w/ t-loc ,now im getting a vibration between 45&65 mph i took it to it back to the installer he said its not in the rear, so i took it to ford & they replaced the driveshaft but the vibration is still there, can any body tell me what it can be ?
Runinng the car on a lift won't put the bearings at full load.
Did you do a full bearing kit with the install? Some kits omit the differential bearings. Mechanic could also have overlooked a bearing. Bearings can make an awful racket.
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tripleblack
"You can never be free until you let yourself go."
I was told that a bearing would make a grinding or a squealing noise ,also I didnt get bigger tires so i was thinking because everything is spinning faster that the rear & the driveshaft & the trans is out of sync, but then why does it go away at 66 mph??
i guess it's a humming sound that you hear. as soon as you hear it again while driving, coast in neutral and see if the vibration that you are referring to is still there or not. if it is, then most likely it's the differential.
I had and have the same problem. Vibrations at 55mph and again at 70mph. Belts shifted on the stock tires from going to the track before I purchased my MT ET streets. Never noticed it untill I rotated the tires along with other mod installs.
Spin the tires, if they move up and down, then the belt shifted. If the rim moves left and right, bent rim.
Was told when vibrations occur and go away it is usually a wheel/tire issue.
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2008 Mustang GT, auto, Procharger Stage II 10 psi, 4:10 gears, Eaton LSD, ATI Ratchet Shifter, SLP line locks, Shaftmasters D/S, BMR Safety Loop, Dash Tripod, Autometer Guages, CDC Aggressive Chin Spoiler, SS Valance, Xenon side scoops, Staggered Bullitts, Roush Off Road Exhaust, CHE uca/lca, CHE axle brace, CHE anti-squat brackets, tinted windows, billet hood pins, b/shield, t/light bezel trim, fog light bezel trim, rear qtr marker bezel trim, sequentials, Headlight Splitters, All lenses Tinted
I have a mean vibration at 80 and up. It just gets worse the faster I go. At 100, it's just plain violent.
I took it to a friend's who has a lift in his garage and some cool tools I never knew existed.
He has this thing with a dial and vice-grip clamp that clamps on the chassis anywhere near the driveshaft. The dial pushes up against the shaft and when we turned the shaft, I found over 50 thousands run-out in the driveshaft.
Basicly, my driveshaft is bent. Maximum tolerance for that is about 20.
I'm now in the market for a new driveshaft.
I think it sounds like it's in your tires because if it were in the shaft, the vibration does not go away as the speed increases. Then again, maybe it does, but I'm not willing to take it any faster to find out. It just gets too crazy.
vibration between45&65 
