The Lotus Elise Series 2, a two-passenger, mid-engined sports car introduced in 2002, is equipped with a rack-and-pinion steering system that lacks any form of power assist. Due to the inherent handling precision that a manual steering rack initially inspires, it can become apparent after a relatively short time that the steering has lost some of its original confidence-inspiring feel. Luckily, the factory has provided a means for adjusting the pre-load between the rack and helical pinion gear. Proper pre-load adjustment is periodically necessary, and reduces unnecessary play in the steering. This repair technique typically allows an owner to avoid the potentially expensive need to replace the entire assembly.
Lift the car to a safe working height onto either four jack stands or an automotive lift, following the guidelines in the owner's manual. Remove the front wheels by loosening the wheel bolts using the Elise-specific wheel bolt tool inserted into a 17mm socket on a breaker bar. Remove the nut from each steering arm track rod end after making each one accessible by turning the steering wheel all the way to one side. Force apart the joints with a suitably-sized ball joint separator tool.
Use a paint pen to mark the current rotational position between the lower steering column universal joint and the pinion shaft before removing the rack assembly from the chassis. This will later aid in proper centring of the steering wheel during reassembly. Loosen the bolt on the universal joint before moving on.
Remove the four bolts accessible from the passenger compartment that secure the steering rack to the chassis. Move the steering rack slightly forward to allow disengagement between the pinion shaft and lower universal joint. Once free, slide the rack laterally out of the chassis.
Loosen the 36mm locknut that retains the backstop plug within the rack housing. Tighten the backstop plug on early racks with a 5.5mm hex key (19mm on later racks) until solid. Before re-tightening the locknut, the backstop plug should be backed off one-half turn (one-quarter turn on later racks).
Use a common bathroom scale protected by a towel to verify that the proper adjustment has been made to the pre-load on the backstop plug. It takes roughly 6.8kg. of force on the scale to push the rack through its entire range of travel. If more than 6.8kg. force is necessary, the backstop plug must be backed out slightly. Conversely, if the rack moves too easily, the backstop plug must be tightened. Continue the iterative process of adjustment until the proper force is attained.
Insert the pinion shaft into the lower universal joint while aligning the marks made earlier. The factory recommends replacing the four bolts that secure the rack to the chassis due to a thread locking compound that comes on the bolts and degrades after a single use. However, the bolts can be reused. Remove any old thread locking material with a wire brush before applying new thread locking compound. Tighten each of the four bolts to factory specifications. Tighten the lower universal joint’s clamp bolt and the two track rod end nuts to factory specifications. Place the wheels back on the hubs and tighten the wheel bolts to factory specification with the Lotus-specific tool inserted into a 17mm socket.
Assess the rack design using the following guide: Early models featured a one-piece cast aluminium rack housing, while later models have a cast pinion housing with assembled steel support tubes. While the procedure for adjusting the thrust pad of both rack designs is similar, there are some important differences that must be noted. It is likely that the completion of this procedure has altered the vehicle’s front end alignment, which should be consequently checked and adjusted to factory tolerances by a qualified professional at the earliest opportunity. Try to enlist the help of a friend or this job. Final steps such as refitting the steering rack to the car can be difficult if they must be completed alone.
Steering rack boot failure is a common underlying cause of Lotus Elise steering rack problems. Due to the damage caused by debris that is typically introduced into the system soon after a boot failure, it should not be expected that this procedure will recover safe operation on a rack that has had a boot failure. In such cases where a boot has previously failed and the steering has been noticeable affected, it is recommended that a new or reconditioned steering rack assembly be fitted. Every vehicle’s steering system is critical to the safety of its passengers, and thus this procedure should only be attempted by experienced individuals familiar with the expectations surrounding the proper maintenance of the vehicle as outlined by its manufacturer.