T-BIRD FRONT END VIBRATION

ultramar wrote:

First off, I apologise if I ruffle your feathers. Second, It seems that you're being a bit too critical of an 11 year old car that has had rebuilding in one area. Your problem sounds to be coming from some rotating mass in the vehicle (bearing,rotor, tire, wheel, driveline....,) if things are as you describe. NVH (noise, vibration, harshnass) is terribly difficult on older vehicles. You describe the symptoms as "slight and occasional". My definition of "slight" is : I have to really be looking for it", and occasional is:just now and then". What are yours? As a car ages, there is no way to "repair" some of the "sometimes" problems with it without major expense. How do you know the problem is "front end"? What you describe is usually an indication of rear driveline concerns. (Universal joints, pinion bearing,etc). It could be caused by slightly worn bushings in the rear trailing arm bushings causing oscillations in the driveshaft due to slightly worn universal joints, etc.... under certain conditions. One thing I've noticed through the years is that: People notice problems with their cars after work is performed. Little things may have been unnoticed before a repair, but after you shell out big$$$ you are looking much closer for problems and unrelated concerns become apparent. Thus "You just fixed my xxxxx, and now yyyyy is happening". Two questions: How many miles on your T-bird? Why did you have all of the font end work done in the first place?

Tom

Hi, Tom:

Thanks for your thoughtful reply.

Feathers unruffled.

I notice everything about every car I drive, and I think that is one mark of a good driver -- rapport with the machine that is carrying you (sometimes very fast) down the highway. So whether it's a vibration that wasn't there before, or a sound that is not produced by the road surface, whatever -- I notice it.

I agree with you that a rotating mass would probably be the culprit, and that diagnosis can be difficult, on older (and newer as well) vehicles.

My definition of "slight:" Something that is noticeable but not alarming enough to make you pull over and get out to look for the cause.

"Occasional:" Yes, just now and then. But no less real than if it were constant.

Why do I think it was the front end? Probably two things, the direction from which it seemed to come, and that I may have felt it through the steering wheel. That's my best recollection.

"People notice problems with their cars after work is performed." I'm sure they do, but the only thing I was actually looking for closely was whether I could tell if the new control arm bushings were having a cushioning effect on road irregularities. I wasn't looking for vibrations of any kind.

The T-Bird (my fourth, I like 'em for several reasons) has about 95,000 miles on it. It has Monroe Sensamatic aftermarket shocks on it, and Michelin H-rated 235-60-15 tires.

The front end work was occasioned by the fact that this car has been local since it was first sold. Local here means rough streets, potholes, railroad tracks, and severe front end punishment.

There was a dangerous amount of play in some front end components, and the protective seals (or whatever you call 'em) on the ball joints were totally shot. I considered that to be an unsafe situation.

John

Hi, Tom:

Thanks for your thoughtful reply.

Feathers unruffled.

I notice everything about every car I drive, and I think that is one mark of a good driver -- rapport with the machine that is carrying you (sometimes very fast) down the highway. So whether it's a vibration that wasn't there before, or a sound that is not produced by the road surface, whatever -- I notice it.

I agree with you that a rotating mass would probably be the culprit, and that diagnosis can be difficult, on older (and newer as well) vehicles.

My definition of "slight:" Something that is noticeable but not alarming enough to make you pull over and get out to look for the cause.

"Occasional:" Yes, just now and then. But no less real than if it were constant.

Why do I think it was the front end? Probably two things, the direction from which it seemed to come, and that I may have felt it through the steering wheel. That's my best recollection.

"People notice problems with their cars after work is performed." I'm sure they do, but the only thing I was actually looking for closely was whether I could tell if the new control arm bushings were having a cushioning effect on road irregularities. I wasn't looking for vibrations of any kind.

The T-Bird (my fourth, I like 'em for several reasons) has about 95,000 miles on it. It has Monroe Sensamatic aftermarket shocks on it, and Michelin H-rated 235-60-15 tires.

The front end work was occasioned by the fact that this car has been local since it was first sold. Local here means rough streets, potholes, railroad tracks, and severe front end punishment.

There was a dangerous amount of play in some front end components, and the protective seals (or whatever you call 'em) on the ball joints were totally shot. I considered that to be an unsafe situation.

John