Here's some info on classifications of tire chains. The classes refer to clearance underneath. You'll need to check your owners manual or truck specs to see if you can use them and, if so, which class you can use. For example, the owners manual on my Dodge 2500 says that I can use class U on all 4 tires. Class U is pretty much unrestricted so I can use any type on it.
With any ladder chains, you need slack adjusters to keep them tight. Even then, most adjusters are rubber or spring loaded. At higher speeds, those will stretch and allow the chains to hit important things underneath.
Most info on using chains is for highway use at higher speeds. If you just use them to get unstuck or at very slow speeds, you can usually get away with slack in the chains that will kill you on the highway. Note that I said 'usually'. That's no guarantee.
Tire Chain Classification and Use
Definition of SAE classification
SAE class S:
Regular, non-reinforced passenger tire chains and cables for vehicles with restricted wheel well clearances.
SAE class U:
Regular, non-reinforced and lug-reinforced passenger tire chains for vehicles with regular, non-restricted wheel well clearances.
SAE class W:
Passenger tire chains that use light truck components, as well as some light truck chains.
Anti-Lock Brakes (ABS) & Four Wheel Drive
Anti-Lock Braking systems are not an alternative to traction devices. ABS assists in maintaining control and managing the vehicle's available traction more efficiently than a conventional braking system. When tire chains are installed, stopping traction for the ABS system is increased.
Although four-wheel drive and all-wheel drive vehicles have greater traction ability than two wheel drive systems, they do not have any advantages in stopping under winter driving conditions. It is recommended that all tires be equipped with tire chains on these vehicles.
Which Tires to Chain Up
Tire chains should be installed on the vehicle's drive tires. On vehicles with front-wheel drive, this would be the two front tires and on vehicles with rear-wheel drive the two rear tires should be chained. If your vehicle has four-wheel drive or all-wheel drive, and you intend on chaining up only two of the tires, refer to your owner's manual for advice on which axle to chain up. To retain the best performance and handling from a four-wheel or all-wheel drive vehicle, install traction devices on all four tires.
Under normal driving conditions, a vehicle has about the same amount of traction at each wheel, creating a feeling of 'normal' control during braking, acceleration and cornering. Under snow and ice conditions, this balance is disrupted. If tire chains are installed on only the front tires, the rear of the vehicle can swing during braking and driving. If snow chains are installed on the rear tires only, the steering ability of the vehicle is limited. To get this balance back, the vehicle should be completely equipped with tire chains. Remember that tire chains are sold in pairs. Therefore, if you intend to install chains on all four tires, you must purchase two pair.
