The box should have little to do with how easy the wheels return to center. That is the steering axis inclination returning the them center along with the caster. Both of those together is what returns the wheels. I read these posts and some people say their steering returns nicely and some guys do not. If everybody is using the same steering box and one guy's returns to center on its own and another guy's doesn't, assuming both gear boxes are good, the problem is not the gear box
If you have changed the offset of the front wheels you have changed the steering axis inclination. All the different steering boxes on the planet are not going to fix that. The box makes it easier steer, slower or faster to steer or harder to steer to provide more feedback to the driver. It has nothing to do with the wheels returning to center. All these aftermarket trick parts do not change the steering geometry's fundamentals If you want the tires to wear correctly, the car to go straight down the road and the steering wheel return on its own the geometry of the frontend needs to be setup for that.
I still found a lot of people saying their steering is not returning to center after increasing the caster per Borgesons instructions. I wonder how many of those people have changed the offset of their front wheels. lowered their front ends or changed the diameters of their front tire. That all has an effect on the steering axis inclination that returns the wheels to center? That cool look is a trade off for the wheels not returning on their own.
Straight off the Borgeson website
STEERING BOX DOES NOT RETURN TO CENTER:
There is nothing inside a steering box or rack that will make it return to center after a turn this is solely a function of the caster setting of the vehicles alignment.
- No Return to Center after Power Conversion Installed. Customers who install our power steering conversion boxes may report a lack of return to center or some wandering on the highway. It is necessary to increase the caster on the left and right front tires to 3-4 degrees positive.
- No Return to Center Steering Feels Stiff. Not likely an alignment issue like above. Have customer lift front end and inspect all steering linkage for binding.
- No Return to Center erratic steering feel. If all components aren’t new it is possible that something has fouled the internal valve of the P/S box causing it to stick open. This would require manual input to stop a turn and to change direction and a very uneasy feel at the wheel. If this is suspected, have customer completely flush and then fill the power steering system with clean fluid and rapidly cycle the wheel left to right to clean out any obstructions.
This came from another site
Steering axis inclination (SAI) causes both front wheels to gain positive camber as the
Without any inclination, no self centering would occur. The Steering axis inclination (SAI) causes both front wheels to gain positive camber as they steer away from center. This acts with caster to provide self-centering of the front wheels. This gives the car straight line stability.
With the wheels in the straight-ahead position, the stub axles are almost horizontal.
As the wheels turn to either side, SAI causes the stub axles to decline and the ends. In order for this to happen the inside end of the stub axle must rise and this in turns raises the front of the car.
The mass of the vehicle pushes down on the stub axles, so when the steering wheel is released, the wheels are pushed back to the central position.
Without any inclination, no self centering would occur. The mass of the vehicle would not resist the wheels from being pivoted by the bump (Bump Steer). The steering would be hard to control and straight line stability would be very low.
Steering Axis Inclination Effects :
