dogstar
03-28-2007, 09:13 PM
Hello all!
I have a bad vibration problem in my 73 series III at certain speeds and conditions. I have checked all the U joints, one was bad in the rear shaft at the transfer case end and I have replaced that. I also found that three of the bolts holding the rear drive shaft to the differential were loose and one was missing. I bought four new identical bolts and secured the shaft. Despite fixing those obvious problems the vibration is still there and actually may even be a little worse. The vibration occurs between 25-30 MPH. It is significantly worse under hard acceleration. If I very gently accelerate through this speed range I can greatly reduce the vibration. If I am in this speed range and disengage the clutch or shift to neutral the vibration goes away. At speeds greater that 30MPH I can cause a less severe form of the vibration by accelerating hard.
This really has me stumped. I am wondering if a bad motor mount could cause such problem. I have one mount that looks rather shabby, but I don't seem to have what I would consider abnormal engine movement when I rev the motor.
Any suggestions would be greatly appreciated.
Thank you,
Dogstar
I have a bad vibration problem in my 73 series III at certain speeds and conditions. I have checked all the U joints, one was bad in the rear shaft at the transfer case end and I have replaced that. I also found that three of the bolts holding the rear drive shaft to the differential were loose and one was missing. I bought four new identical bolts and secured the shaft. Despite fixing those obvious problems the vibration is still there and actually may even be a little worse. The vibration occurs between 25-30 MPH. It is significantly worse under hard acceleration. If I very gently accelerate through this speed range I can greatly reduce the vibration. If I am in this speed range and disengage the clutch or shift to neutral the vibration goes away. At speeds greater that 30MPH I can cause a less severe form of the vibration by accelerating hard.
This really has me stumped. I am wondering if a bad motor mount could cause such problem. I have one mount that looks rather shabby, but I don't seem to have what I would consider abnormal engine movement when I rev the motor.
Any suggestions would be greatly appreciated.
Thank you,
Dogstar