Serious steering problem.....

rightwinged

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May 7, 2010
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new bern
I have a 86 k5 with 8lug 10bolt front end. Its been having a serious problem lately, that started several months ago. Its well beyond death wobble. The tires wont wobble side to side, but instead top to bottom, as if theres very loose balljoints installed. Bad enough to where my caliper mounting plate will hit my knuckle when i go over a small bump. So to start, checked all steering components, put 4 new balljoints, all new wheel bearings, seals. Jacked it up, absolutely no play side to side or top to bottom. I measured how center the front axle is, and its off by almost an inch. The driver side is almost an inch further foward then the passenger side.So, checked the center pins, both are beautiful and intacked. 1st problem...how is the front axle off that much with the center pins being in great shape? 2nd problem..not sure the offcentered axle would cause that type of wobble.Im out of ideas, and ran out of things to check/replace. Any thoughts would be appreciated.
 
are the tires alright? put the rear tires up front and see if that helps. sometimes the tires will have dead spots if they sit for a while. dont kno if thats the case but figured id throw an idea.
 
Keep measuring things from from to front to back until you find it. Measure both springs eye to eye and compare. Might have a flat spring on one side that is kicking the shackle back. Check the shackle bushings in the frame. One side could be destroyed and shifted back. Bent spindle? You eliminated a bent rim or bad tire already. Have you changed any parts lately? Have you beat on it offroad recently? Hard to fix it without seeing it. I dunno', just some thoughts.
 
Nctom, I recently installed crossover steer, with d44 knuckles, etc... But it couldnt be anything i installed because it was doing this before I put crossover on. I checked the upper shackle bushings, there dryrotted and pretty easy to move with a prybar. Im thinking this is the culprit, but would a toast upper bushing really make it wobble that much? Or to me in the cab, it might seem like the tire, but is actually entire leaf/axle/tire assembly bouncing because of the toast bushing? If someone could validate that theory, or tell me im retarded, thatd be great. Thanks. And recomendations for new bushings if anyone feels thats it.
 
I'm still trying to figure out how the caliper bracket is hitting the knuckle from the wheel wobbling. That tells me that there is play in the wheel bearings. It's the only way you'd get movement in that area. I don't care how much the wheel wobbles, unless the bearings are loose or your rotor is waaaayyyy warped you should not be getting that much movement out of the backing plate/caliper.
When you say the wheel is wobbling top to bottom, is that what you're seeing out the window when it actually happens driving?
 
Its what im seeing to a point, obsivisouly i can only see the driver side, and that does it no where near as bad as passenger side. But, when i hit a bump on D/s i can stick my head out and watch it wobble top to bottom. I had my money on wheel bearings or ball joints, but there is absolutely no play. Im thinkin i might have to set up one of those little video cameras to catch it when it happens. Appreciate the feedback, marsfab, its baffling me as well, because it makes absolutely no mechanicial sense.
 
Replaced both shackle bushings on the frame side, still does the exact same thing. Im starting to think that my caster might have a lot to do with it. It is shimmed 5 degrees, which might be too much. Any alignment gurus out there? thanx
 
you mean you got 5 degrees of a measured angle, or you just stuck 5 degrees of shim in your spring mount. If the line drawn down from the upper joint to the lower joint is verticle or worse yet leaning forward at the top it will never drive very good. you will be in effect driving the steeering into the ground. The angle should be so that the upper joint is pointing rearward. Caster around 7 is a good starting point. I dont let myself get confused by calling it positive or negative, just the top pointing rearward. This allows the turning angle of the knuckles to work smoother and work with the driving force of a vehicle going forward. In effect this allows the steer forces to float the tire in the turning arc. Check the toe in too. tires should point toward each other in the front, measured at the centerline height front and rear of the tread surface (measured in the same place on the patern or the tire centerline). 1/8 to a 1/4 works here for me. Camber isn't adjustable unless you've severly tweaked a tube or knuckle C. You could isolate that by measuring the spindle travel arcs for differences which is related to the ackerman angle (sp) but that takes special tools.
 
I'll also add I've seen intact spring center pins cause all kinds of axle alignment issues. specificly after hard wheeling or a curbing or wreck. The whole pack will shift and push the pin around at a diagonal or partial shear. It's much worse in larger multi leaf packs. Seen this mostly on very large packs on firetruck chasis and fullsize rigs with homebrew or "national spring" packs ie several leafs. UNdersize pins for the spring bore cause this too.
 
My old chevy did this once we put crossover steering and 39's on it. If there were not at least 3 steering stabilizers on it, you could not drive it. I changed everything that could be changed with no effect on the problem. Even added a panhard bar. It did not stop till I build hydro assist for it.
 
warriorwelding, i used the whole angle finder on knuckle,(i know not the most reliable method) and it was 6 degrees total towards the front, like you said, driving the tires in the ground. Should i take the shims out in the front ( should bring it to 1 degree foward) and see how it drives like that?
 
The only place you'll get an accurate measurement is to clean the top of the upper ball joint and sit the angle finder on top of it front to back. I can't imagine that you have 6* of negative caster unless you have your degree shims in backwards. That much negative caster will cause your truck to drive like ass but I seriously doubt it's causing the problem you're describing.
What front shocks are you running? Standard "white" shocks? Any chance they are mounted upside down. If so the valving in them will do absolutely nothing so if the tire is out of balance or cupped it will let the tire bounce. What you're describing sounds like a shock or tire issue to me.
I know you said your tires are balanced and everything but what kind of tires are they? Could they be mud tires that are cupped really bad. Or maybe big like 38's or something with a lot of soft sidewall Do you have headlocks?
 
Did almost exactly what you said marsfab, and the angle finder still reads 6 degrees, with the axle rotated foward. Shocks are bilstein 5100's, so its safe to say that the shocks arent the problem, and i wouldnt see how they are mounted upside down(what would be the rubber boot is on the top). its got 8" lift and 40s. They are DC FC2, maybe a year old. No beadlocks, and all spring mounts are factory. Took out both center pins, and there straight as a grizzlys dick.
 
rightwinged said:
Did almost exactly what you said marsfab, and the angle finder still reads 6 degrees, with the axle rotated foward. Shocks are bilstein 5100's, so its safe to say that the shocks arent the problem, and i wouldnt see how they are mounted upside down(what would be the rubber boot is on the top). its got 8" lift and 40s. They are DC FC2, maybe a year old. No beadlocks, and all spring mounts are factory. Took out both center pins, and there straight as a grizzlys dick.
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You should be able to read the Bilstein engraved on the shock in it's upright position as I was told from the factory rep.
 
Yup, there mounted correctly... which leaves the tires, caster and toe. I dont see how it would be the tires, unless they were balanaced incorrectly, maybe i should reseat them with alot more airsoft bbs inside?
 
I think your best bet would be to find somebody with a more like stock size tire to bolt on it and see if it still happens. That'll tell you for sure.
 
I don't know a lot about chevys but I know they are bad about cracking the frame at the steering gear box. By friends blazer had the same symptoms when his frame cracked . Might be worth looking into.
 
Borrowed my buddies 35's, that have less then 100 miles on them, it didnt do it quite as bad, but still did it. i have ords frame brace kit installed, and the frame is in beautiful shape.
 
Sorry for being late to chime back in (been working on stuff). If your angle is reading what your saying it's dead wrong from what it needs to be. And its probably One hundred percent your problem. That's pending everthing else is correct as said. As for shocks, they only dampen spring or suspension movement. If a shock affects the ride that dramaticly it is either froze on the shaft or severely bent. Unless its an air shock it does not provide spring rate. Even the gas charged Bilsteins don't have enough pressure to cause severe issues like this, besides they are internally valve for high speed compression to prevent darting not allow it!
 
I just re read this AND the 8 INCH lift caught my eye.
Check the distance from each spring eye to the center pin. 8 inch lifts are useually all spring lift with a degree shim. The distance to each pin will be different from the front of the pack and from the rear of the pack. Make sure one or both packs aren't installed backwards. THIS WILL MAKE THE AXLE WAY OUT OF CENTER. And mess up the steering angle because the degree shim will also be backwards.

Something else to check hope it helps.
 
WARRIORWELDING said:
Sorry for being late to chime back in (been working on stuff). If your angle is reading what your saying it's dead wrong from what it needs to be. And its probably One hundred percent your problem. That's pending everthing else is correct as said. As for shocks, they only dampen spring or suspension movement. If a shock affects the ride that dramaticly it is either froze on the shaft or severely bent. Unless its an air shock it does not provide spring rate. Even the gas charged Bilsteins don't have enough pressure to cause severe issues like this, besides they are internally valve for high speed compression to prevent darting not allow it!
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A bad shock could very likely cause this problem. Or an upside down shock. You are correct the shock does just dampen the suspension movement and tire bounce. When you go over a bump with big 38" balloons they bounce causing almost exactly what he is describing. With that much arch in his springs he needs shocks more for tire bounce than suspension movement anyways.
You do have a good point with the springs. Ive actually got a set of 8" chevy springs in the shop now that Im using for a SAS. The center pin is centered in them and they are completely symmetrical front to rear but they do have a degree wedge and it very likely could be reversed. I think it's only a 3* or so but that would make it way off if it was. Definitely something worth checking out. Remember... with the front axle you don't shim the pinion to line up with the d-shaft, you shim to correct caster.
 
I appreciate all the great feedback..Took all tires to get rebalanced today, 3out of 4 were still very close, but the 4th was 8 grams out of balance. Put them all back on, exact same thing. So unless the something is wrong with the tire (which he should have noticed while trying to balance them) then its not the tires. I am going to measure center pin to eye tonight, although im almost positive i measured them when i put them on, but im going to double check it.
 
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