So what's this all about?

Jeb_Bush_2000 · 05-02-2002, 11:44 AM

I have a driveline vibration that I attributed to a bad rear U-joint.

At highway speeds, between 60 and 80mph, when I let off the gas, my car shudders violently. Putting the clutch in makes no difference. When the throttle is open, the vibration ceases, and it stops completely at WOT or near-WOT. Those are the symptoms of a bad U-joint, right?

Well I dropped the car off the other day to get some work done, along with replacing the rear U-joint. My mechanic took it apart, and was going to replace it, but he told me it "looked perfect" and it would be a waste of money to replace. So my question is, what else could cause a vibration like that? I would assume it's the driveshaft, but wouldn't it vibrate all the time if it was out of balance? I always thought the bad U-joint caused that vibration because when you applied torque to it (opened the throttle), it shifted back into position and remained relatively balanced.

I know it's not the rear-end. I know it's not the tires. I know it's not a steering problem. I know it's not a transmission problem. I know it's not engine-related.

I am totally stumped.

05-02-2002, 11:44 AM	#1
Jeb_Bush_2000 Registered Member Join Date: Jul 2001 Location: Taxachusetts Posts: 374	So what's this all about? I have a driveline vibration that I attributed to a bad rear U-joint. At highway speeds, between 60 and 80mph, when I let off the gas, my car shudders violently. Putting the clutch in makes no difference. When the throttle is open, the vibration ceases, and it stops completely at WOT or near-WOT. Those are the symptoms of a bad U-joint, right? Well I dropped the car off the other day to get some work done, along with replacing the rear U-joint. My mechanic took it apart, and was going to replace it, but he told me it "looked perfect" and it would be a waste of money to replace. So my question is, what else could cause a vibration like that? I would assume it's the driveshaft, but wouldn't it vibrate all the time if it was out of balance? I always thought the bad U-joint caused that vibration because when you applied torque to it (opened the throttle), it shifted back into position and remained relatively balanced. I know it's not the rear-end. I know it's not the tires. I know it's not a steering problem. I know it's not a transmission problem. I know it's not engine-related. I am totally stumped. __________________ Stripped-down '93 LX Coupe -- "Danielle" R.I.P. 05/30/02 "I've seen some crazy stuff in my life, but that...was...AWESOME!!! Oh, sorry about your car, man."