chengny
Full Access Member
- Joined
- Feb 22, 2012
- Posts
- 4,084
- Reaction score
- 1,024
- Location
- NH
- First Name
- Jerry
- Truck Year
- 1986
- Truck Model
- K3500
- Engine Size
- 350/5.7
Before you take it to a shop and pay good money - lift the tires one at a time and check them for an out-of-round condition.
Using a stable reference point - like a jack stand placed so that the support plate is very near to the tire - slowly spin them by hand. Watch the gap between your reference point and the tire tread as it passes by. Any change greater than 1/4" in that gap indicates that he tire has internal damage and is no longer round.
Also, while you have each tire off the ground for inspection, do as Zach says and check for excessive bearing play (this would pertain to the fronts mostly). Get down low, grasp the tire in both hands and (without making the steering linkage move) rock it by pushing on the left/right and also on the top/bottom. You should feel essentially no free motion. If the outer edges of the tire can be seen to move more than 1/4", you should tighten your front wheel bearings.
The thing about loose wheel bearings is - that condition doesn't usually cause a shimmy/vibration. The general result of loose/worn front bearings is looseness in the steering which makes the truck want to drift at higher speeds. In others words, it makes you need to constantly steer the truck. So, if you look away for even a brief time - when you look back, you can be halfway into the next lane.
Using a stable reference point - like a jack stand placed so that the support plate is very near to the tire - slowly spin them by hand. Watch the gap between your reference point and the tire tread as it passes by. Any change greater than 1/4" in that gap indicates that he tire has internal damage and is no longer round.
Also, while you have each tire off the ground for inspection, do as Zach says and check for excessive bearing play (this would pertain to the fronts mostly). Get down low, grasp the tire in both hands and (without making the steering linkage move) rock it by pushing on the left/right and also on the top/bottom. You should feel essentially no free motion. If the outer edges of the tire can be seen to move more than 1/4", you should tighten your front wheel bearings.
The thing about loose wheel bearings is - that condition doesn't usually cause a shimmy/vibration. The general result of loose/worn front bearings is looseness in the steering which makes the truck want to drift at higher speeds. In others words, it makes you need to constantly steer the truck. So, if you look away for even a brief time - when you look back, you can be halfway into the next lane.
