Steering effort while standing still or tight maneuvers

[Torqued]

This past week I test drove an Avanti I am interested in. The first thing I noticed was the high effort required during very low speed tight turns. It felt like almost zero assist in tight maneuvers. Like a manual steer car. Once you got rolling the car steered well. 

This cars past service history lists a p/s valve replacement. In searching the forum here, I see several discussions on p/s issues. I am trying to understand the nature of these cars. I have zero experience driving one until now. I have had GM cars of the 80's era, the same year as this Avanti. The p/s effort is minimal in the conditions described. Am I just accustomed to the GM level of assist?

How much effort does a proper functioning Avanti p/s system require in low to no motion conditions?

 

[Torqued]

Anyone??? Over 70 views. Yet no input?

 

[ronmanfredi]

The system on the Avanti is more similar to the 60's Ford models where you have a control valve connected to the gear box that makes a hydraulic cylinder (ram) push or pull on a bell crank pivot (mounted on the crossmember under the engine) which connects to the wheels by 2 long tie rods.  The design isn't as quick as a more modern GM PS gear box and there are several places where problems may occur.  Usually it's either a sloppy, worn out bushings/pins or leaking control valve, ram and hoses.  The control valve design does have 1 pressure adjustment that improves its effectiveness.  The end cap of the valve assembly has 2 slotted screws in it.  If you remove the end cap, there is a nut that you can adjust to change the pressure.  You want to tighten the nut all the way to tight and then loosen by One Flat.  This gives you the highest pressure.  Any decent rebuilder should know this, but it needs to be check.  If you have fluid in the cap when you remove it, then the spool valve seals are leaking. The control valve has a spool inside of it that moves back and forth to send fluid to the ram to either push or pull depending on the steering wheel / gear box action.  The spool valve has identical ends as far as the seals go but it can be installed backwards, which can affect its effectiveness also. 

[mfg]

I’ve experienced Studebaker Avantis and early Avanti ll’s (all with p/s) having less steering effort than the later Avanti ll’s (through ‘85)

All power steering components are the same between these cars EXCEPT the steering box itself, which was changed out when the supply of Ross boxes ran out.

Some say the replacement steering box was originally made for a fork lift … I do not know if that’s true or not.

But a change in ratio between the two units could have an effect on steering effort.

I can say steering effort in my ‘63 Avanti is definitely less than in my ‘83 Avanti.

PS…. It occurred to me that a change was also made in the power steering pump itself, going from the Eaton style to the GM style… If there was less pressure produced by the GM pump, I suppose that could account for additional steering effort.

Edited 1 hour ago by mfg
Added text

[Adam DeRosa]

With power steering, the effort required at low speeds will likely be more than what you may be used to on a modern car, It will not be "0ne-finger" steering. The force required at low speeds will be affected by many factors, including: front tire pressure and size, condition and lubrication on the king-pins and steering box, adjustment and condition of the power steering components, and whether the later "quick steering" arms have been installed. Of course, if there's a doubt as to if the power steering is working at all, the easiest way to check is to compare steering effort when parked with the engine running vs without the engine running.