12th January 2023
By Gavin Kelso
This session’s topic deals with steering, which, along with brakes, is a critical part of building hot rods.
Steering is a critical element of vehicle building that needs to be done to sound engineering practice if you want a safe project car. Let’s look at some of the key elements:
• Steering should take a priority at the start of building a hot rod. It is unwise to leave to a later stage of the project with the engine and exhaust already in place. This ultimately leads to steering arrangements with multiple universal joints and support bearings to avoid obstacles between the steering column and the steering box or rack and pinion. It is not ideal to have more than the minimum number of moving parts in a steering setup.
• Most builders mock up their vehicles to check clearances and correct functionality. Then they tear them down again for final welding and detailing. It’s at this stage that steering has a chance to be prioritised with a simple two universal and intermediate shaft arrangement leaving exhaust and engine location to fit around the steering. At this stage, universal joint angles can be set to avoid acute angles that result in notchy steering or binding.
• In today’s hotrods we see collapsible steering columns (with breakaway mounts in some States) with uni’s and double D shafts to the steering box or rack and pinion. Watch out for clearance along the way so that smooth steering operation is not compromised by exhaust or other engine bay elements. Remember that engines vibrate at idle and move under load. We see plenty of vehicles with tight clearances that leave contact marks on the steering shaft or where an engine mount failure will also cause loss of steering.
• Welding of steering components is not allowed unless it’s factory sourced from a donor car and meets the ADR’s.
• We could write a book on steering geometry, but the point is that builders should be aware of the rules of steering geometry to avoid bump steer and inadequate turning circle.
• Correct installation of steering stops is important to avoid any over-centre turns and to avoid the steering box taking loads that can damage the internals if a wheel hits an obstacle on full lock.
Check out the pictures to see the kind of things we find during inspections.