Diagnosing Stiff Spots in the Power Steering System

Print-ready PDF export — generated on 29/08/2026

911Tech
Model:Porsche 911
Type:964
Category:Chassis
Difficulty:Difficult

Any rough spots felt while the engine is running may be caused by the hydraulic system, the steering column, the seals, or the rack. Before removing any parts, check the fluid level and condition, the belt, the steering column universal seals, the ball seals, and the system pressure.

Figure 5.1 — Removed power steering rack, general view showing its hydraulic lines.
Figure 1 — Removed power steering rack, general view showing its hydraulic lines.

Overview

Any rough spots felt while the engine is running may be caused by the hydraulic system, the steering column, the seals, or the rack. Before removing any parts, check the fluid level and condition, the belt, the steering column universal seals, the ball seals, and the system pressure.

Figure 5.2 — Rack shaft and teeth exposed after opening the housing.
Figure 2 — Rack shaft and teeth exposed after opening the housing.

Overview of the rack

The overview of the removed rack allows you to identify the lines, the input pinion, and the orientation of the components before opening. Take a photo of each position before disassembly.

Figure 5.3 — Close-up of the grooves showing signs of wear and deposits.
Figure 3 — Close-up of the grooves showing signs of wear and deposits.

Explanation

As you can see in Figures 5.3 and 5.4, the grooves have undergone some changes, in addition to very heavy buildup on the inside.

Figure 5.4 — Rack teeth with an area of wear indicated by the arrow.
Figure 4 — Rack teeth with an area of wear indicated by the arrow.

Inspection of the Teeth

This close-up shows a marked area on the teeth. Inspect the entire length of the rack: a tooth that is worn down, pitted, or deformed can cause a sticking point and compromise safety.

Figure 5.5 — Interior of the bearing showing corrosion, old grease, and grooves.
Figure 5 — Interior of the bearing showing corrosion, old grease, and grooves.

Inspection of the bearing and splines

The inside of the bearing housing shows deposits, old grease, and signs of corrosion. Simply cleaning it is not enough if the guide surfaces or the teeth are damaged.