Need Help Troubleshooting a Vibration
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Senior User
Joined: Jan 2006
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Need Help Troubleshooting a Vibration
Hey foks, I've got a very fine vibration coming from somewhere on my truck that has been there ever since I bought it used several years ago. Nothing that I do seems to fix it. Its not a real bad vibration, but is rather a very fine (for lack of a better term) vibration that is very annoying to me. The truck is a 1992 F250 LWB, two wheel drive. It has the 302 engine and E4OD tranny. I can't tell where the vibration is coming from, but I'm feeling it in the seat of my pants when driving. The vibration will start at around 40 mph and will almost disappear at about 55 mph. Once the speed gets up to around 70 mph, it will start up again. When I let off the gas it disappears. When I get back on the gas, it starts up again. This is what I have done so far: Front end alignment, re-balanced the tires, new shocks, new u-joints. I also had the transmission rebuilt about a year ago and they replaced the torque converter at that time. I would sure appreciate it if any of you could offer any suggestions for me to look at that might cause this problem. Thanks.
Hotshot
Joined: Sep 2001
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That does really sound like a tire or wheel that is out of balance. Are all of the wheels straight?
An out of balance driveshaft causes similar symptoms. Look and see if there are any small weights attached to your driveshaft. Maybe one fell off. Just for curiousty you could try using a large hose clamp and put it around the driveshaft and see if it helps any. It may make the symptoms worse. You will have to rotate it a few times to see if it changes anything when you drive the truck.
One thing that is commonly overlooked and is a somewhat common problem on many Fords is torque convertor shudder. From what I have seen though it seems that this only occurs at lower speeds, but I am not an expert on that subject.
It could also be a rear end issue.
It is possible that transmission or motor mounts or other suspension bushings are not in good shape.
I would look under the truck and check the tightness of all the suspension and mount bolts and see if any are loose. Also look and see if any of the supension bushings are shot.
An out of balance driveshaft causes similar symptoms. Look and see if there are any small weights attached to your driveshaft. Maybe one fell off. Just for curiousty you could try using a large hose clamp and put it around the driveshaft and see if it helps any. It may make the symptoms worse. You will have to rotate it a few times to see if it changes anything when you drive the truck.
One thing that is commonly overlooked and is a somewhat common problem on many Fords is torque convertor shudder. From what I have seen though it seems that this only occurs at lower speeds, but I am not an expert on that subject.
It could also be a rear end issue.
It is possible that transmission or motor mounts or other suspension bushings are not in good shape.
I would look under the truck and check the tightness of all the suspension and mount bolts and see if any are loose. Also look and see if any of the supension bushings are shot.
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Senior User
Joined: Jan 2006
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Tires were my first thought also. I've had the tires rebalanced and the wheel run-out checked and both are good. Just about the only thing that I haven't done is have the drive shaft rebalanced and replaced the pinion bearing. The hose clamp idea is a good one. I'll give that a try. Thanks.
