I honestly can't contribute any info regarding motor mounts or drive shaft issues in reference to vibration, but I do have experience in vibration caused by bad/defective tires.
First, I would not recommend buying tires from any discount "center" or "club"-type store to be installed on the type of cars in this forum. (I won't mention any names, but I think you get the picture).
They tend to buy "seconds"...why do you think they can sell them so cheap? The tire manufacturing process does have SOME variation in it and that variation will show up in a non-round tire or a tire with a sidewall with variation.
When you get tires installed or balanced, ask for Road Force Balance. This device is similar to the balance machine we're all used to seeing, but it has a roller in the back which puts pressure on the tire as it spins (makes the tire think it's on the car).
This roller then detects and measures any variation in the side wall as the tire spins...called Road Force Variation. It will also detect if the tire is out of round...because it's possible to balance a square tire with enough weights!!
The variation is measured in pounds and any tire over 9-10 pounds of variation will give you problems
(I've had tires purchased from "clubs" have close to 40 pounds of variation!)
This type of balancing costs more ($60-$90) but in the end it's worth it especially with finely tuned suspensions.
Lastly, you can get tires with "cold spots" on them. This happens in ANY climate. When a car sits for a peroid of time the tire developes a flat spot in it. This varies with companies and is probably due to the composition of their particular tire "recipe"..maybe carbon content. This flat spot will disappear after a while.
Hope this lends some insight.
First, I would not recommend buying tires from any discount "center" or "club"-type store to be installed on the type of cars in this forum. (I won't mention any names, but I think you get the picture).
They tend to buy "seconds"...why do you think they can sell them so cheap? The tire manufacturing process does have SOME variation in it and that variation will show up in a non-round tire or a tire with a sidewall with variation.
When you get tires installed or balanced, ask for Road Force Balance. This device is similar to the balance machine we're all used to seeing, but it has a roller in the back which puts pressure on the tire as it spins (makes the tire think it's on the car).
This roller then detects and measures any variation in the side wall as the tire spins...called Road Force Variation. It will also detect if the tire is out of round...because it's possible to balance a square tire with enough weights!!
The variation is measured in pounds and any tire over 9-10 pounds of variation will give you problems
(I've had tires purchased from "clubs" have close to 40 pounds of variation!)
This type of balancing costs more ($60-$90) but in the end it's worth it especially with finely tuned suspensions.
Lastly, you can get tires with "cold spots" on them. This happens in ANY climate. When a car sits for a peroid of time the tire developes a flat spot in it. This varies with companies and is probably due to the composition of their particular tire "recipe"..maybe carbon content. This flat spot will disappear after a while.
Hope this lends some insight.
