Drive line grinding/vibration

[Harold R.]

57 fuelie under heavy acceleration there is a grinding/vibration noise. Only occurs with heavy acceleration. There is no evidence of anything rubbing or hitting anywhere. Would appreciate any ideas anyone may have.

[Edward J.]

Re: Drive line grinding/vibration

Harold have you looked the drive shaft U-joints? They will cause a driveline vibration under accel and make a grinding type noise when the internal needle type bearings inside the cups loose there lubrication, They will start to get chewed up in quick order.

[Harold R.]

Re: Drive line grinding/vibration

I haven't looked at the U joints but that is an easy place to start. Thanks for the suggestion.

[Mike M.]

Re: Drive line grinding/vibration

if the u-joint's zerk fitting(or just the plateau cast for a zerk) was incorrectly installed so that the zerk fitting is in close proximity to the pinion shaft, it may be bottoming out on the pinion shaft under accelleration. the plateau should face towards the front of the car, not the differential. mike

[Mike M.]

Re: Drive line grinding/vibration

PS: if the u joint is contacting the pinion shaft, you'll see a dent in the shaft. mike

[Paul J.]

Re: Drive line grinding/vibration

57 fuelie under heavy acceleration there is a grinding/vibration noise. Only occurs with heavy acceleration. There is no evidence of anything rubbing or hitting anywhere. Would appreciate any ideas anyone may have.

Do you feel the vibration through the steering wheel or the seat? If it's through the steering wheel then it's your tie rod ends. If it's through the seat then it can be u-joints, an axle bearing, something in the rear end, or even a motor mount.

Paul

[Harold R.]

Re: Drive line grinding/vibration

replaced "U" joints and it solved the problem. Thanks for every ones comments

[Mike M.]

Re: Drive line grinding/vibration

was the zerk plateau bottoming out on the pinion shaft?mike

[Paul J.]

Re: Drive line grinding/vibration

Harold,

U joints fail slowly. When they are so loose that the bearings are about to fall out, they will vibrate a lot at speed. However, when they just starting to fail they will squeak. If you roll the car slowly beside of a wall (preferably masonry) at 3-5 mph you can hear the noise. It will go "squeak squeak squeak..." rapidly.

Paul

[Harold R.]

Re: Drive line grinding/vibration

No the u joints had been installed incorrectly. The caps were not down inside the built in retainer and had backed off. the u joint shaft was actually bent.