Suspension help needed or maybe confirmation

[rockhound66]

I have decided to post here after reading some great "how to's" and needed a bit of guidance. This forum seems to be the most straight forward of the many I have surfed.
The Facts: I purchased a 2000 4WD Blazer LT last Saturday. The people who had it always paid to have it worked on and had a bad run of problems and a few bonehead mechanics I learned. They had tired of dumping money into it. It had classic fuel pump symptoms and I told them so. They said they had the pump replaced a month earlier and weren't going to spend another dime on the Blazer and bought a new car. I bought it cheap and trailered it to my house.
Got it home and hooked up the fuel pressure gauge, 60 PSI when pump kicked on but fell to 10 when it cycled off. Bad check valve in the new pump. Replaced the pump again and I was on my way.
Drove like a nightmare though, all over the road with bad bump steer. 142K miles with original ball joints. So a full set of Moog joints, idler arm and alignment cured 90% of my problems. The last 10% is tough to determine though and hard to describe.
When I hit a bump at highway speeds now I get a movemnet that is best described as a fish swimming. The truck tracks straight down the road and steering wheel remains true, it just "wobbles" sort of. My research had led me to belive control arm bushings may be the culprit. The shocks dampen the bounce fine and the movement is more side to side than up and down. That is pushing me in the bushing direction. Oh and I put a new set of Yokahama tires on it and all are properly inflated.
Any thoughts or input?????

[viggy58]

i think you might be dead on about the control arm bushings. especially if the steering feels good. i am not a suspension expert however. so ya might wait to wait for another opinion before you dive in.

[old_master]

Worn control arm bushings will cause the vehicle to wander from side to side randomly while driving. Smooth or bumpy roads will make no difference, each time you correct the steerng, it will want to wander, sometimes left, sometimes right, and rarely go straight for any length of time. If they are worn bad enough, you can actually hear the control arm shifting around. An alignment technician, (even one with half his marbles) couldn't miss it while "trying" to align the front wheels.

What you're describing is bump steer. "Sudden sideways movement of the vehicle, without driver input, over bumps, more noticeable while on a curve". It's caused by the steering linkage not being level. When the idler arm is replaced, before tightening the bolts, the center link must be level. The idler arm mounting holes are slightly over size in the frame to allow for the adjustment. If you adjust it now, you'll need to have the alignment redone, (the adjustemnt will affect toe in). When the vehicle is on level ground, measure from the end of the center link up to the frame on each end. If it needs adjustment, loosen the idler arm bolts and move the center link up or down to make both sides equal. Then tighten the bolts and align the front end.

[Scrapper]

Originally Posted by rockhound66

I have decided to post here after reading some great "how to's" and needed a bit of guidance. This forum seems to be the most straight forward of the many I have surfed.
The Facts: I purchased a 2000 4WD Blazer LT last Saturday. The people who had it always paid to have it worked on and had a bad run of problems and a few bonehead mechanics I learned. They had tired of dumping money into it. It had classic fuel pump symptoms and I told them so. They said they had the pump replaced a month earlier and weren't going to spend another dime on the Blazer and bought a new car. I bought it cheap and trailered it to my house.
Got it home and hooked up the fuel pressure gauge, 60 PSI when pump kicked on but fell to 10 when it cycled off. Bad check valve in the new pump. Replaced the pump again and I was on my way.
Drove like a nightmare though, all over the road with bad bump steer. 142K miles with original ball joints. So a full set of Moog joints, idler arm and alignment cured 90% of my problems. The last 10% is tough to determine though and hard to describe.
When I hit a bump at highway speeds now I get a movemnet that is best described as a fish swimming. The truck tracks straight down the road and steering wheel remains true, it just "wobbles" sort of. My research had led me to belive control arm bushings may be the culprit. The shocks dampen the bounce fine and the movement is more side to side than up and down. That is pushing me in the bushing direction. Oh and I put a new set of Yokahama tires on it and all are properly inflated.
Any thoughts or input?????

i agree on upper control arm bushings and have you looked at stable lizzer links and bushings they wear out to and snap the bolt and it will cause your sterring problems.

good luck............

scrapper..............