Okay I got a re-occurring problem. First some history and facts: I installed a new (old system new parts) Power Steering system in the 68 last year. I had some problems then and adjusted the power steering control valve until it was balanced in the middle quite well. It seemed to operate okay but not as easy as I thought it would. I decided to live with it, as it was an improvement on the old non power steering.

I also got an alignment last year and my settings were as follows:
FRONT:
Caster Left: 2.4* Right: 2.4*

Camber Left: -0.1* Right: 0.1*

Toe: Left: 1/16" Right: 1/16" Total: 3/32"

REAR:
Camber Left: 0.1* Right: 0.1*

Toe: Left: 0.0" Right: 0.0" Total: 0.0"

Thrust Angle: 0.0*

The previous owner(s) installed on the front suspension new bushings, ball joints, tie-rods, idler arm, spindles, bearings, larger diameter sway bar, springs. (550lb). The rear suspension has a new VB&P fibreglass mono spring and added a sway bar.

I’m running 255/60/15 BF Goodrich T/A Radials with 26 lbs of air. I was noticing some wondering so adjusted the power steering control valve again and it is centred again. It was off a centre again…. Should it need centring again?

The re-occurring problem:

I find on some corners (usually hard ones when I'm pushing it a little) the power steering will pulse with effort to a real easy turn then back to what it was before. This of course causes the car to turn sharper for a 1/4 second as the steering wheel will turn sharper because I am really cranking it in the corner. Besides scaring the $hit out of me it is dangerous. This is very more pronounced if there was a bump/crack or deep groove in the road. It will also jump from side to side when there are ruts in the road made by the HEAVY loaded trucks.

TODAY the wife and I were coming home from a car show and I pulled out to pass a slower car on a straight away and during the pass I crossed a cement bridge with a large ‘crack’ in the pavement where the cement and pavement met each other. When the front tires hit this crack the car’s steering literally bounced the car sideways to the right about a foot or more. I was already past the car I was passing so I was nowhere near that car but it sure scared the $hit out of me. (and worse the Wife TOO!!!)

The Wife refuses to ride with me now until I get this FIXED. Do I need another alignment? Do I need to replace my control valve as I have read that sometimes that even a new one may not operate properly right out of the box. Would new narrower tires on the front help? More/less air pressure?

I’m reaching for straws here guys. I need help. I just remembered that my steering is a little loose as I have a little play in the steering wheel. It’s not much. I can move the wheel from 12 o’clock both ways about a ½ hour each way. I’ve driven vehicles with WAY worse than that and NOT had any kind of similar problems.

Sorry this is a little long but I am trying to give all the information I can to try to get to the bottom of this problem. I LOVE to and want to do LOTS more but this is starting to get scary. We want to go on a 2000 mile road trip this September but if this isn’t fixed we won’t be taking the vette.

Thanx for any all suggestions.

shmoky

 

You could well have a control valve issue, which I'll leave to others more knowledgeable on the subject, and might could use a new rag joint, but I'd get your rear toe corrected in any event. VBP has as good a reference chart (link below) as I've seen, so I suggest starting there. ...and don't accept work not done to minimal tolerances.

http://www.vbandp.com/View-document-...ent-Specs.html

 

get an alignment and that'll be your sign if something else is off.

for me, it has recently been the power steering control valve, tire rods-and next going to try replacing the rear right wheel bearing and front right control arm and if thats not enough, gearbox work but it may not be as much work for you if your alignment came out fine a year ago.

just as a heads up-i'm not a mechanic but my bro is and has been helping me try to get this resolved from out of state. if you can't do the work yourself-find a neighborhood shop with plenty of cars in the lot, preferably old muscle and let us know what they charge you on this forum for we can help assess long-term relationship.

hope this helps,
ivan

 

shmoky,

Your power steering system was designed before you were born, most likely, and there is a far better system available from www.borgeson.com in Connecticut. Since 1914, they have been supplying steering components to OEMs and just last year, they introduced a modern integral power steering box for the C2 and C3 Corvettes.

Based on a modern Delphi 600 series box, this one has the control valve ( a MODERN one) and the power ram built into the steering box. With a 12.7:1 ratio, this box will make your car drive like a 21st. century car and you'll wonder why you didn't make this change earlier.

Regards from Down Under

aussiejohn

 

I would also check with someone who works on alignments. Im pretty sure on ind. rear susp. You need toe out to allow for suspension travel so You dont get toe in which can be dangerous on these cars. I could be wrong but its worth looking into. Here is how My car was set-up last week.Everything is in degrees
FRONT:
Left camber=.75 Right camber=.75
Cross camber=.0
Left caster=2.25 Right caster=2.25
Cross caster=.0
Total toe=.5

REAR:
Camber=-.88
Total toe=.25
Hope this helps . Good luck

 

It soulds like the SCV has a rough spot in it. Happened on the 77 I used to have, it would jump to one side or the other sometimes with a slight steering input. As stated above, there are better systems available these days, if your going to rip into it, a new box or rack system would be the way to go. The cheap fix wouold be replacing the control valve

 

WOW, I had the EXACT same issues on my 68.. I did everything to the front end and nothing solved it.. Come to find out, it was actually the rear end causing what felt like the front end..

You said the previous owner replaced the rear spring and installed a sway bar but what condition is everything else like the trailing arm bushings and strut rod bushings? After I rebuilt my entire rear end, those problems went away.. I'm not sayng that is your problem for sure but your issues are EXACTLY the same as mine "were"..

 

Well I'm afraid this is dead wrong. Static rear toe IN is required, especially if your half-shafts travel beyond level in bump during cornering, to avoid rear toe out. This is a C2/C3 design fault.

 

You may want to double check your Idler Arm...just check to see if you have any up and down play. Most references say you should have no more than 1/8 inch travel up or down. The standard idler arms use plastic bushings that do not have the best life in a high heat environment.

If it turns up bad, try a Moog Idler arm...they have compressed metal bushings that should have a much longer life.

Best of luck