Steering Box

Series I Aurelias

Lancia Aurelia steering box sectional drawing
From Ref. 7 SI-Tav. 46

Series II Aurelias

Lancia Aurelia steering box sectional drawing
From Ref.6 SII-Tav. 47
Part Notes on Steering Box
Steering box (Scatola) The steering box is a worm and roller type which remained almost the same throughout production (see above notes) On Series I cars the horn electrical circuit was taken off through a unit attached to the steering box. The drop arm is connected by a steering arm and track-rod to the stub axles. Motion of the arms is about lubricated swivel pins for the steering arm and silent-bloc bushes for the track-rod
Lubrication The oil capacity is 300 ml on all models (0.53 pints, 0.63 US pints). S1 cars were recommended Mobilube GX90 or Esso Gear oil GP90. SII cars were recommended Mobilube GX140 or Esso XP Compound EP140. Access for lubrication: remove radiator grille; remove Alan key filler plug in lid of steering box.
Oil Leaks This is most likely to come from the needle rollers and associated seal and gaskets at the base of the steering box. There is also a gasket for the lid of the box.
Adjustment Bad wear usually requires replacement or refurbishment of the worm and roller. The normal problem being that reduction of play at the centre of steering movement results in very stiff motion at the extremes, or possibly vice versa. Small degrees of play can be adjusted by turning the screw & lock nut in the centre of the steering box lid (SII-Tav.47#9-#16)
Steering Box Removal and Replacement

These guidelines are based on experience with B20 4th and 5th Series.

  1. Disconnect battery and remove horn-ring assembly. This is helped by lifting the front wheels clear of the ground so that the steering wheel may be revolved easily.
  2. Remove 32 mm centre-nut and lock washer from the steering column.
  3. Pull off steering wheel with puller located into threaded holes provided. A rubber hammer and brass drift may be successful instead of a puller, after undoing the clamp at the bottom of the steering column. A puller is recommended.
  4. Undo 3 screw-bolts holding centring plate and bearing. Prise off and remove, but it will still be attached by the wire for the horn.
  5. Replace steering wheel and centre nut, but not tight.
  6. If not already loosened, remove clamp-bolt and clamp locating the bottom of the column to the steering box. (14mm nut and bolt head, and split pin to be removed). Access to the clamp is by removing the radiator grille)
  7. Pulling on the steering wheel should allow the column to pull off the splines of the steering box. However the job can be very difficult if the splines are rusted or damaged. The following may be of help – An unwanted steering wheel or tool which can be pulled or hammered freely; Heat on the clamped area of the column, but not too much as this will damaged the column and the seals of the steering box.
  8. Remove steering arm clamp from the drop-arm of the steering box (14mm nut, 14mm bolt-head & split pin). Place steering arm on top of the track-rod, or tie the two together to prevent damage to the steering joints.
  9. Remove the 4 12mm nuts & washers holding the two halves of the steering box assembly, half of which is approached from below the car.
  10. Remove the steering box. This may require moving the horn.


Steering Box Reassembly

  1. Reverse the removal procedure but note the following
  2. Do not tighten the steering box to the car until the column has been assembled onto the splines. Otherwise the angle will not be right for the column to engage with the rather fine splines.
  3. Before replacing the column onto the box note:
    a: Set box to centre position with steering wheel set correctly
    b: Replace bottom clamp with bolt and nut
  4. Before replacing the steering rod drop-arm, remember to have the steering box at its centre position with the front wheels pointing straight ahead.
  5. Lightly grease all the splined shafts
  6. Check that the box is full of oil (see above notes) to 1cm below the plug.
  7. Note that the steering box must be placed on the cross-tube so that the column is axial with the car and that there is no strain or binding at the upper bushing of the column.


Steering Box Overhaul

Refer to SII-Tav.47 above. Apart from lubrication & leaks the following may require attention.
Ball races #6 is RIV 9053/Lancia 2048303 Dimensions 40mm od, 17mm id, 12mm wide #7 is RIV 9054/Lancia 2048304 Dimensions 47mm od, 20mm id, 14mm wide
Ball cage #8 is the steering pin thrust bearing (a cage with balls) RIV 4306/Lancia 2048702 Dimensions 40mm od, 25mm id 3/16 inch-3 wide
Steering pin #34 are 84 needle rollers RIV 99172469/Lancia 2049401 Dimensions 11mm long, 2mm od
Sector/Wheel gear #35 is secured by 8 locked nuts and bolts (#2 & #10), which are torqued to 20.25 ft.lbs. or 27.5 N.m. on reassembly. Use Tool 8091142 or similar – 14mm socket
Steering box cover Nuts #13, which secure the cover #3 to the steering box body #36, are torqued to 10.1 ft.lbs. or 13.7 N.m on reassembly. Use Tool 8091139 – 10mm socket