1970 Duster power steering issue

[Toqwik]

The original owner of my 1970 340 car put power steering on the car. He said it is too fast and will swap lanes too

fast. He did not change the crank pulley. The pulley appears to be the same as the others as far as size. The car also has dealer installed ac in 1970 and those pulleys are the same. Does the pulley need changed? A smaller pulley to me would increase pump pressure.

 

[Tooljunkie]

Perhaps its a quick ratio gearbox,pitman arm too long or alignment is way off. Small steering wheel?
Could always go back to manual steering. Or put a bus-sized steering wheel on.

 

[Demonic]

Don't confuse pump pressure with bad alignment. The old ones with high PS pressure is a different feel if you aren't used to it, but it shouldn't steer squirrely. How does it drive?

 

[72bluNblu]

Don't confuse pump pressure with bad alignment. The old ones with high PS pressure is a different feel if you aren't used to it, but it shouldn't steer squirrely. How does it drive?

Exactly.

Overboosted power steering and swapping lanes unexpectedly are completely different problems. Probably time for a front suspension rebuild and an alignment.

 

[Toqwik]

Exactly.

Overboosted power steering and swapping lanes unexpectedly are completely different problems. Probably time for a front suspension rebuild and an alignment.

I have not driven it yet. Been waiting to get insurance on it before I attempt to start it. Lots of stereo wires everywhere to remove. I do have the original box but he said when he did the swap it steered to easy and needed a pulley change. Bought from the original owner, in his 80’s.

 

[Toqwik]

I have not driven it yet. Been waiting to get insurance on it before I attempt to start it. Lots of stereo wires everywhere to remove. I do have the original box but he said when he did the swap it steered to easy and needed a pulley change. Bought from the original owner, in his 80’s.

Also has the original steering wheel.

 

[bill richardson]

My 70 Dart 340 has the same pump and pulley setup as yours, steering is sensitive but doesn't cause driving issues. Seems common for that vintage of car, GM was almost the same from 60's thru 70's, drove a lot of them. Just a matter of getting used to it.

 

[AJ/FormS]

Over 20 years ago,I pirated the complete system from a 70 Duster340,and installed it on my 68Barracuda. I agree it was over-boosted, but it steered very well; even with a small fat-rimmed steering wheel. I reduced the sensitivity and the lowered the pressure, and now it's even better.
But the old man is right, the p/s boxes are ratio'd about 50% faster; 16:1 versus 24:1 for the manuals.
Don't bother with pulley sizes, the pressure is controlled by a hi-pressure relief valve on the back of the pump.

 

[67dartgtgo]

Lots of guys have done this...
Pump It Down....EASY
Reducing the pump pressure to the box and that over boosted feeling.
I'm not saying this is your issue as it's a matter of feel. Def explore everything else first as there could easily be something else going on there.