One thing that let the rover p5 down was the vague steering, speak to any one that drove them back in the day and they will say very light steering and constantly needed correction at speed. Drive one now and they can be even worse with worn and tired parts so I decided to take a further look at what could be done to improve straight line tracking.
It appears that when the car was designed and supplied new it had no power steer option and to make the steering feel easy to steer they sold these cars with NEGATIVE castor angle of 2 degrees. later in the production run power steering was available but no change was made to the caster angle, hence the vague steering.
The rover has a very antiquated front suspension design with longitudinal leaf springs with upper and lower wishbones holding an upright between two swivel joints.
The first thing to do is measure the caster angle that exists, here is a tool that fits between the upright swivels that allows a digital angle finder to read off the angle compared with the horizontal with the car in it's normal ride height position.
It appears just enough space is available to move the top of the wishbone half rearwards by 19 mm leaving sufficient clearance with the wider wheels I have on this car After making a "jig" to ensure things would be the correct shape so I set about making two half's of the wishbone ( one for each side)from bright mild steel and forming with very little heat.
Making sure of enough penetration with the welder
Produced this
Painting things
After reassembly the caster was measured and found to be correct at 2.5 degrees each side
Now after reassembly and a test drive the car drives much better at speed and even now has self cantering steering after turning a corner. A great improvement.
The next thing on the list to sort out is the tendency for the car the need steering correction after going over a bump, not quite bump steer but similar.
It appears that when the car was designed and supplied new it had no power steer option and to make the steering feel easy to steer they sold these cars with NEGATIVE castor angle of 2 degrees. later in the production run power steering was available but no change was made to the caster angle, hence the vague steering.
The rover has a very antiquated front suspension design with longitudinal leaf springs with upper and lower wishbones holding an upright between two swivel joints.
The first thing to do is measure the caster angle that exists, here is a tool that fits between the upright swivels that allows a digital angle finder to read off the angle compared with the horizontal with the car in it's normal ride height position.
It appears just enough space is available to move the top of the wishbone half rearwards by 19 mm leaving sufficient clearance with the wider wheels I have on this car After making a "jig" to ensure things would be the correct shape so I set about making two half's of the wishbone ( one for each side)from bright mild steel and forming with very little heat.
Making sure of enough penetration with the welder
Produced this
Painting things
After reassembly the caster was measured and found to be correct at 2.5 degrees each side
Now after reassembly and a test drive the car drives much better at speed and even now has self cantering steering after turning a corner. A great improvement.
The next thing on the list to sort out is the tendency for the car the need steering correction after going over a bump, not quite bump steer but similar.