Hello guys, I have an issue that has me stumped. I recently started a new job downtown and had to travel more highways with the mustang. I noticed a driveline shimmy or vibration around 65mph in 4th gear, under load, TC locked and slight throttle. It just shook my car like my driveshaft was slightly off balance... not violently. When I let off the throttle the shimmy goes away. Give it throttle, it's back.. and so on.
I took it to my trusted shop and they looked it over. They came back and said the rear-end is in need of rebuilding, citing that my pinion seal was shot, as was my carrier bearing. Clutch packs were completely worn out, pinion was loose, spider gears had seen better days. Also my U-joints were bad. I was thinking, great, that sounds like it was the culprit, I mean who wouldn't think that?
Well, me being me, I opted for the 31 spline cobra T-lok/axle setup. I also opted for a new set of 3.55's over the 3.73's to try and save some gas mileage.
Got it back yesterday, get on the highway this morning and the shimmy is still there, but it's not at about 70-75mph and it feels just like a rear tire is heavily out of balance. You feel it in the seat and throughout the car, the steering wheel is steady. And like before, let off the gas, it goes away and the car rides like a dream. Also, my SES light came on. Getting that checked tonight.
So, it's not the rear end, and its not a wheel balance issue. It only vibrates at certain speeds, but only under load(throttle).
Any ideas?
I took it to my trusted shop and they looked it over. They came back and said the rear-end is in need of rebuilding, citing that my pinion seal was shot, as was my carrier bearing. Clutch packs were completely worn out, pinion was loose, spider gears had seen better days. Also my U-joints were bad. I was thinking, great, that sounds like it was the culprit, I mean who wouldn't think that?
Well, me being me, I opted for the 31 spline cobra T-lok/axle setup. I also opted for a new set of 3.55's over the 3.73's to try and save some gas mileage.
Got it back yesterday, get on the highway this morning and the shimmy is still there, but it's not at about 70-75mph and it feels just like a rear tire is heavily out of balance. You feel it in the seat and throughout the car, the steering wheel is steady. And like before, let off the gas, it goes away and the car rides like a dream. Also, my SES light came on. Getting that checked tonight.
So, it's not the rear end, and its not a wheel balance issue. It only vibrates at certain speeds, but only under load(throttle).
Any ideas?
