Pretty good explaination and example of "wheel hop" if you're interested
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Not DAVEB the parts guy
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Pretty good explaination and example of "wheel hop" if you're interested
Here is one of the best explainations of wheel hop I've read:
Car & Driver "Wheel Hop":
"An undesirable suspension characteristic in which a wheel (or several) moves up and down so violently that it actually leaves the ground. Wheel hop can be caused by many problems, including excessive unsprung weight, insufficient shock damping, or poor torsional axle control.
Wheel hop is one of the wildest mechanical temper tantrums a car can throw. Our tech feature, "How We Test Cars," on page 154 reminded me of the once-common phenomenon. In the presence of a peculiar mixture of high traction, limited compression damping, and just the right ratio of unsprung to sprung weight, a wheel or two will leap off the pavement briefly during hard acceleration.
As it rises an inch or two, the driven wheel speeds up when it's airborne, only to be jerked to a halt when it's grabbed by the pavement on its descent. If you keep your foot in it, the wheel then launches again to repeat the process, leaving a neat dotted line on the pavement as it hops up and down numerous times per second.
A hopping wheel doesn't produce much forward thrust, but it does play havoc with the driveline. Imagine the stress on the axle shafts, universal joints, gears, and bearings when these components are repeatedly accelerated and stopped.
No imagination was required two decades ago when I was testing a 1982 Oldsmobile Firenza, one of the original GM J-cars, the guts of which still soldier on in today's Chevrolet Cavalier and Pontiac Sunfire. Equipped with a manual transmission, that front-drive Firenza had hellacious wheel hop. About 50 feet into its third acceleration run, the thrust and the wheel hop suddenly ceased.
I braked, opened the door, and looked behind the car. Between the twin dotted lines of rubber laid down by the hopping tires was an oil trail sprinkled with numerous ***** and rollers that had been liberated from the Firenza's transaxle. When I and the none-too-happy GM engineer peeked under the car, we saw the transaxle had split open like a ripe peach, exposing its gears and shafts to the elements."
Dave
Car & Driver "Wheel Hop":
"An undesirable suspension characteristic in which a wheel (or several) moves up and down so violently that it actually leaves the ground. Wheel hop can be caused by many problems, including excessive unsprung weight, insufficient shock damping, or poor torsional axle control.
Wheel hop is one of the wildest mechanical temper tantrums a car can throw. Our tech feature, "How We Test Cars," on page 154 reminded me of the once-common phenomenon. In the presence of a peculiar mixture of high traction, limited compression damping, and just the right ratio of unsprung to sprung weight, a wheel or two will leap off the pavement briefly during hard acceleration.
As it rises an inch or two, the driven wheel speeds up when it's airborne, only to be jerked to a halt when it's grabbed by the pavement on its descent. If you keep your foot in it, the wheel then launches again to repeat the process, leaving a neat dotted line on the pavement as it hops up and down numerous times per second.
A hopping wheel doesn't produce much forward thrust, but it does play havoc with the driveline. Imagine the stress on the axle shafts, universal joints, gears, and bearings when these components are repeatedly accelerated and stopped.
No imagination was required two decades ago when I was testing a 1982 Oldsmobile Firenza, one of the original GM J-cars, the guts of which still soldier on in today's Chevrolet Cavalier and Pontiac Sunfire. Equipped with a manual transmission, that front-drive Firenza had hellacious wheel hop. About 50 feet into its third acceleration run, the thrust and the wheel hop suddenly ceased.
I braked, opened the door, and looked behind the car. Between the twin dotted lines of rubber laid down by the hopping tires was an oil trail sprinkled with numerous ***** and rollers that had been liberated from the Firenza's transaxle. When I and the none-too-happy GM engineer peeked under the car, we saw the transaxle had split open like a ripe peach, exposing its gears and shafts to the elements."
Dave
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