New steering box mounting bolts, drag link and track rod balljoint nuts, and rubber coupling clamp bolts will be required on refitting. Begin by chocking the rear wheels, applying the parking brake, jacking up the front of the vehicle, and supporting it on axle stands. Set the front wheel in the straight-ahead position and lock the column using the steering lock, avoiding rotation of the column while the steering box is removed. For models with power steering, clamp both the supply and return hoses near the steering box to minimize fluid loss, mark the unions for correct reassembly, then slacken and remove the union nuts, being prepared for fluid spillage. Plug the hose ends and steering box orifices to prevent leakage and dirt entry. Make alignment marks between the lower end of the steering column, rubber coupling, and steering box pinion, noting that unbolting the steering box heatshield(s) may be necessary for access. Slacken and remove the clamp bolts, then slide the coupling upwards to disengage it from the steering box pinion. Unscrew the nuts securing the track rod and drag link balljoints to the steering box drop arm, freeing the balljoints if necessary with a universal balljoint separator. From underneath the wheelarch, slacken and remove the three steering box mounting bolts and manoeuvre the steering box out from underneath the vehicle. Examine the steering box assembly for wear or damage; if overhaul is necessary, it should be entrusted to a Mercedes-Benz dealer, although the steering box seal can be easily replaced. If fitting a new steering box, position the steering pinion correctly prior to installation. For early models, unscrew the plug and sealing ring from the side of the steering box, then rotate the pinion until its centring hole aligns with the plug aperture, securing it with a special tapered locking screw if available. For later models, align the index mark on the steering gear pinion with the mark on the steering box housing. Manoeuvre the steering box assembly into position, aligning the marks made on removal or ensuring the pinion is centred, and engage it with the rubber coupling. Slide the rubber coupling fully into position, fit the new steering gear mounting bolts, and tighten them to the specified torque. For early models, remove the centring bolt if necessary and refit the plug and sealing ring. Fit the new coupling clamp bolts and tighten them to the specified torque. Insert the drag link and track rod balljoints into the steering box drop arm, then fit the new retaining nuts and tighten them to the specified torque. For models with power steering, reconnect the fluid hoses to the steering box and tighten the union nuts securely, then refill and bleed the hydraulic system.