If your steering box is not available new, you will have to make a choice; either find a used steering box with the possibility that it may have the same defects in the foreseeable future, or overhaul your existing one.
This last option is increasingly used, even if the steering box is available as new, your Bus retains its originality.
The retaining ring or shaft seal mentioned here is located around the output shaft on which the steering arm is fixed and must be replaced at each inspection.
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