Severe Wheel Hop

[RayG]

My 2002 Chevy Avalanche 4WD with 55k on it has developed what feels like wheel hop. It has had the inner tie rods replaced, has been aligned and checked over by the dealer. However, on the highway, when hitting a pothole or a bridge plate transition, the vehicle shudders at minimum, and at worst, a violent vibration (feels like the front left wheel oscillating up and down) start and does not stop for 15-20 seconds. (until vehicle slows) Application of th ebrakes does nto seem to have an affect. At higher speeds (80MPH), ist is so violent as to give concern that I might lose control of the vehicle. Dealer is telling me that it's tires or shocks, but I've never had shocks or tires cause this kind of problem. It's similar to driving over a very rough cobblestone road (if you had no suspension components!) I'm going to put new tires on it, but I'm sure this will not solve the problem. Anyone have any ideas?

[snidelywhplsh]

I have 02 Z71 ,and had same problem(s).
Noticed right tire was cupped. Replaced tires, helped some what.( I am anal about tires anyway ). Took to dealer and complained about that, leaking right front shock, and clicking noise in steering column.
Dealer called next day and said 3 of the new tires were bad ? But they replaced front shocks and lower steering shaft under warranty and told me to go to the tire dealer and get 3 new ones.
Picked it up that night and got on interstate and guess what ? problem solved !
I did take it back to the tire shop and had them " road force match balance" tires again ( because i'm anal ),and just got back from a 750 mile trip and no problems.

Just fyi,
snidelywhplsh

[RayG]

Thanks much. Maybe it is shocks...I'll get tires this week and we'll see.

[AV-Fan]

Originally Posted by RayG

My 2002 Chevy Avalanche 4WD with 55k on it has developed what feels like wheel hop. It has had the inner tie rods replaced, has been aligned and checked over by the dealer. However, on the highway, when hitting a pothole or a bridge plate transition, the vehicle shudders at minimum, and at worst, a violent vibration (feels like the front left wheel oscillating up and down) start and does not stop for 15-20 seconds. (until vehicle slows) Application of th ebrakes does nto seem to have an affect. At higher speeds (80MPH), ist is so violent as to give concern that I might lose control of the vehicle. Dealer is telling me that it's tires or shocks, but I've never had shocks or tires cause this kind of problem. It's similar to driving over a very rough cobblestone road (if you had no suspension components!) I'm going to put new tires on it, but I'm sure this will not solve the problem. Anyone have any ideas?

RayG,

I have the same problem. My problem started at about 52,000 miles. My truck starts to shake a 68 mph and then stops shaking when I get past 75 mph. I have replaced all four tires and aligned wheels. Truck still shakes. Mechanics have pull drive shaft and said the there was a leak in the front shocks. They were planning on replacing the u joint, but said it doesn't look too bad.

The mechanics are baffled. I've heard that it may be sleeve bearing on the drive shaft (if I have one) I've also heard that it has to be a rotating part, like the tires, rim, brake rotors, brake drum, or drive shaft train.

I may try replacing the front shocks like snidleywhplsh. I am not sure about the lower steering shaft. I also had cupping problems. However, when the alignment was check it was not too bad.

AV-Fan

[AV-Fan]

RayG,

The mechanics found a leaky and bent shock upfront. They ended up replacing all four shocks and vibration problems went away. The rotating machinery theory did not apply. It was the shocks.
John