Chris Schutt, technical training specialist for Bee Line Co., said accuracy, repeatability, and longevity are important considerations when selecting a piece of alignment equipment. Service cost is also key. “You don’t want a piece of alignment equipment that requires expensive or inconvenient software updates, expensive replacement components, and other after-the-sale costs,” Schutt said.
Doug Felt, technical training manager for Hunter Engineering, said wheel alignment machines are available in various forms. Each style has its own set of pros and cons.
Mechanical equipment represents the oldest and simplest of the designs. In many cases, this equipment is also the least expensive. One downside is that this equipment can be user intensive. “The technician makes a multitude of decisions on equipment setup which makes it challenging to have repetitive results,” Felt said. “Furthermore, measurements may be interpreted differently between users. Also, front wheels are not referenced to the rear wheels in most cases.”
Mechanical/digital systems typically measure rear wheels mechanically and front wheels digitally. “One benefit is that digital measurements mean finer measurements and no need for interpretation,” Felt pointed out. This equipment is also slightly less user intensive. On the downside, the technician still must make a multitude of decisions on equipment setup for rear wheels. Thus, rear wheel measurements may be interpreted differently between users, and front wheels are not referenced to the rear wheels in most cases.
Fully digital systems are offered as either a four- or six-sensor set. Since all wheels are measured digitally, measurements are finer with no need for interpretation. Setup is easier and operation is more efficient. “Six-sensor sets can measure a steer axle and two drive axles simultaneously,” Felt pointed out. “This is great for a quick alignment check of two- or three-axle vehicles. This equipment is also great for diagnosing alignment-related pulls caused by tandem scrub. This equipment does require a greater initial investment.”
Quick check commercial systems allow someone to drive a vehicle between the digital pedestals to measure all direct tire wear angles. Felt said this setup can allow for the measuring of a three-axle truck and two-axle trailer in 15 seconds, providing instant results with no need for a technician. “The fleet does need to dedicate space in its shop for this setup,” Felt added.
Floor alignments. Felt said performing wheel alignments on a flat floor has advantages and disadvantages. On the plus side, aligning on the floor is convenient with no need for additional investment. A shop has additional length when needed so it can service longer vehicles. A trailer can also be measured while attached to the tractor. On the downside, access to alignment adjustments is reduced. “Additional labor time is needed in some cases to remove cross tube when front total toe cannot be adjusted due to binding,” Felt explained.
Pit alignments also have pros and cons. Felt said one advantage is that a pit allows easier access to front-toe adjustment and rear-axle adjustments when the pit is of a T-configuration. Adjustment time is also typically reduced, and fleets have that extra length when needed. Disadvantages include the initial cost of pit installation. “In some instances, a pit is simply not an option for some shop locations due to environment,” Felt added.
Alignment lifts also allow easier access to front-toe adjustment and rear-axle adjustments. Initial cost could be of concern for some fleets. “The length of the alignment lift runways determines the size of vehicles a shop can service,” Felt added.
