No RTC (return to center) with steering, CPP

['68 Newtricks]

Details first:
LS swap with stock pump
CPP series 500 steering box
Stock center link with all CPP TREs
CPP modular spindles
5-6* negative caster
Tiny amount of toe in
Zero camber


Truck has no slack in steering, which is nice, but it's also tighter than (enter your own). The truck feels like a go cart, not in the good way, more like it's twitchy and takes concentration to drive. It also has no RTC, I mean ZERO. My big blazer with hydro assist has more and that's not right LOL. The '68 drives straight as an arrow but tends to wonder because the steering is so tight.

Before I pull the pitman arm off and try moving the steering, checking if there is a hang up some place, does anyone have any pointers or experience with this? If the power steering pump lines are switched, would it act like this or not even work? It takes some effort to move the tires while it's not rolling. More than one finger, spin the wheel kinda thing. It's not manual steering feeling, kinda between that and power. Even with manual steering, you still have RTC. ggrrrr

Any tips?
Thanks

[sduckworth13]

Look up Nick Carter "BMERDOC". Here is a alignment thread he started with lots of info.
http://67-72chevytrucks.com/vboard/s...d.php?t=563219

['68 Newtricks]

Is the pressure port on the box the larger port or smaller port?

BTW, can't believe they sell boxes with metric, pfff.

Sorry, asking here is better than calling cpp

[RodnRudy]

Shouldn't the caster be positive instead of negative? That's what helps steering return to center.

[sduckworth13]

Originally Posted by '68 Newtricks

Is the pressure port on the box the larger port or smaller port?

BTW, can't believe they sell boxes with metric, pfff.

Sorry, asking here is better than calling cpp

The larger port is the high pressure.

['68 Newtricks]

Originally Posted by RodnRudy

Shouldn't the caster be positive instead of negative? That's what helps steering return to center.

I believe its negative caster. Whichever leans back lol

Originally Posted by sduckworth13

The larger port is the high pressure.

Thanks, thats how I have it.
Oldly enough, today I can barely hear the beginnings of the power steering pump whine. Fluid is new, pump has 88k on it before the swap. I wonder if the box is effed up, making it not RTC and work the pump harder.

['68 Newtricks]

Does anyone else have this issue? Not so much with the steering set up I have, but stock or slammed and modified?

[sprint_9]

I would check the preload on the steering box. This should be set by whomever built it, but it might not be correct.

[Lattimer]

Caster should be positive, which is top of spindle behind bottom of spindle. IF yours is negative, that would create the twitchy feeling and no return to center.

http://www.aligncraft.com/terms/terms.html

Unless you have aftermarket control arms or you have done the caster mod, 5-6 degrees positive is pretty hard to get. I fought like hell to get 2 degrees positive on my truck without doing the caster mod. I could, however, get a lot of negative with no sweat at all.

I would also recommend running -.5 to -1 degree of camber. Truck will handle better in corners that way with very little effect on tire wear.


IF you really do have that much positive caster, then it has to be binding somewhere, but that wouldn't explain the twitchy feeling.

[tsetsaf]

Sounds to me like the adjuster on your steering box is too tight. These need some play. When we finished my truck the steering was all messed up and could not figure out why. Turned out we had installed the cross arm (the bar that connects left to right) upside down.

['68 Newtricks]

Awesome. Let me see....

I am running CPP arms which helped get the 5-6° caster. This is the upper BJ farther back than lower BJ.

I am at zero camber, which was the best I could do at the time. I need to put a small notch in the upper crossmember area where the cross shaft is almost hitting. With that, I can remove another shim, which doesnt get me much but its better than zero.

Once I find my small metric wrenches, I can try to adjust the steering box again. The lock nut came off easy and the center pin followed, so if it was tight it wasnt by much. I just cant separate the two right now.

I'll double check the center link though I'm fairly certain all the stuff is in right. Who knows, maybe a joint is bad or collapsed and rubbing. Its all 100% new so I would hope not.

Currently, the truck is having the gears checked. I got a funny coast vibration when I had it out. Otherwise I would be all over it right now.

[steelhorse]

Caster should be positive. That much negative caster will cause drivability problems.

[67 chevelle]

Make sure the box is centered lock to lock , maybe slightly more toe in , I had one of CPPs boxes in my chevelle , it was very tight to start with , steering got easier over time , butt it always tracked and drove straight , responsive , and "felt right" at speed , my alignment guy is very good , that was with a standard big block pump , L S's have higher pressures .

['68 Newtricks]

Finally got around to pulling the tierods off. Both spindles are VERY hard to rotate. I think I've got ball joint issues. Not sure what's up, but the A-arms, ball joints, and spindles are all CPP with less than 1,000 miles on them.

When I say hard to rotate, I'm coming from a 1 ton 4x4 blazer with adjustable kingpin preload. I know how knuckles should rotate

Will update when CPP rep responds to my new email.

[Houston Ben]

FWIW, I just put new moog upper and CPP lower control arms on my 86'. To move my stock spindle side to side like I am turning is very hard. But I also did not have RTC with the worn out stock ball joints either.

[Ruscal]

I had the same issue when I first assembled mine. Brand new Proforged ball joints that had too much friction. I switched to Moog and all was well. When they manufacture the joint they have to crimp the assembly at just the right dimension to achieve very little drag and no slop.
Russ

['68 Newtricks]

interesting

I'll be pulling the spindles off this weekend. Hopefully it's just one ball joint (upper or lower) on both sides. I'm hoping it's the upper, which is removable without the need for a press

['68 Newtricks]

Ok, now I'm at a loss again. I checked the spindle resistance with the suspension at full droop. With the ball joints at ride height, the spindles move freely.

With the tierods off the spindles, the steering wheel spins with little resistance. I think the droop was making the steering wheel hard to turn with everything together.

BUT, now I'm stuck. Why is the steering so hard to turn while driving? The larger port on the steering box is the pressure port correct?
I wonder if there's a way I can drain the box. Then run the pump back into itself. Test drive the truck without any assistance from the pump.

Frustrating. This truck is not easy to drive the way it is now.

['68 Newtricks]

'68 turning ratio is 3.25 turns lock to lock
S10 turning ratio is 2.25 turns lock to lock (stock zq8 box)

The S10 is still far easier to turn with the wheels in the air.

The '68 has a 2005 LS, with an 88k mile stock pump. I can tell, after putting almost 1k miles on since complete, the pump is starting to whine. It is super faint but I can tell it's not happy.

I've read about some other people having a similar issue, but with completely different vehicles. I understand the box is supposed to be "tighter" in ratio than a stock box, but I never really drove the truck with the stock box. I can rotate my S10 steering wheel with one finger while off the ground, the '68 I cannot. CPP says it's a 2 finger turn, fine, but the S10 still has a quicker ratio. Never mind the wide tires, they are in the air. I also bled it with the wheels up, engine off. Same method I used to bleed my hydro assisted Blazer's steering. There has to be something wrong with the box. Even if I had ZERO pressure from the pump, it should still return to center. Yes, 5* caster, even better than the S10's.

Also, it has a new steering column. Nothing frozen

[Houston Ben]

Hi 68,
I just replaced my steering box with a CPP500 today as well and I still have the same problem. As stated above, when I first put on the new CPP lower control arms and moog upper control arms the the spindle was very hard to turn side to side (in the air with not tire on and not hooked to any linkage) by hand. The old ones I could move with my pinky before I took them off. I think we are having the same problem and I think it has to do with the CPP control arms. I am planning on loosening the ball-joint caster nuts and re-torque them to a smaller foot pound.

My truck is very hard and scary to drive right now especially on the freeway and this is making me crazy!!

Are you still having your problem?

['68 Newtricks]

Yes, still very much having a problem. I have started working on other issues with the truck and haven't driven it in over a month.

When you turned your knuckles (without linkage) were they jacked up to ride height or hanging down like in the picture above? They will be very hard to turn like this. At ride height they are "easier" but not quite right.

What do you mean by "ball joint caster nuts"? You mean the castle nuts for the ball joints? Loosen them up one step and put the cotter pin through the next hole?

[Houston Ben]

Ha, yes, I meant castle nut, don't know how caster got in there. Whey I turned the knuckles without the linkage they were hanging down like that so I will try this weekend to jack up the a-arm, remove linkage and try and turn.

[Houston Ben]

Hi 68,
Was able to mess with the truck this weekend but nothing changed. I took the wheels off, loosened the upper and lower ball joint castle nuts and beat on the spindle till the top came loose, but I was unable to break the lower ball joint loose. I have the tool, just didn't want to use it for fear of ruining the boot. I greased both ball joint zerk fittings re-torqued the bottom then top and put it back together. I did this to both sides and nothing changed!!!

What I didn't do is take the tie-rod off and try to move the spindle/knuckle by hand. I am going to get the trucks alignment done this week to see if this improves anything, if not, I am at a loss for what is wrong. If the alignment doesn't work, I plan to take the spindle off and try one ball joint at a time to see which one is creating the stiffness and go from there. I am not happy as both upper and lower arms are brand new.

I will keep you posted.

[Houston Ben]

Any news?

I did not take the linkage off for test but I did go get an alignment and still no good. I guess I will have to break the linkage and see what is going on....

[Ruscal]

I cut one of the defective ball joints apart to see what was going on, and learn how it was constructed.
The spherical ball and socket have a spring stacked on top that takes up slop as the pieces wear. On worn joints you can take big channel lock pliers and squeeze the assembly. You will see the joint compress. The more wear the more it compresses.
On these tight new joints the manufacturer crimped the joint too tight, compressing the spring completely which binds the joint. It would take some time to wear them in which would be unacceptable.
You could conceivably put the joint in a press and loosen it up, but controlling how much to push would be a crap shoot.
New Moog joints worked out of the box for me, but the Pro Forged were too tight.
My control arms are Hotchkiss, not CPP. No binding full bottom, top, left, right.
Russ