So, a week ago I replaced both the pitman and idler arm with GM parts. Immediately I noticed that the steering became noticeably "easier". Here's what I mean. Replacing the idler and pitman arm made a huge difference in "tightness" of my front suspension as I don't get the slap in the steering wheel when I'm going into a turn such as a freeway on ramp, but now my steering is VERY sensitive to inputs from the steering wheel. It's rather scary driving on the freeway as the slightest move on the steering wheel causes my truck to veer ever so slightly. I tightned everything on my truck when I was done, and re-tightned everything once again to make sure I didn't forget anything. I had the Cognito braces on before replacing the pitman and idler, and I put them back on after replacing both parts. I took it in to have it aligned so the picture you see below is my printout. Any recommendations? I really need to figure this out, it's driving me nuts.

http://img.photobucket.com/albums/v296/crazyjeeper/Link%20Junk/IMG-1.jpg

Anybody? Help...please.:o:

You don't have enough positive caster on either side up front. That's why the vehicle feels unstable at speed and the steering effort is low.

You don't have enough positive caster on either side up front. That's why the vehicle feels unstable at speed and the steering effort is low.

Is this typically a problem with leveled rigs?

They're SUPPOSED to account for the angle the truck is sitting at then adjust the caster accordingly, no matter if truck is stock,leveled or lifted

IE you have 2.5 in each side but the frame is 1 degree up in the rear, to get an actual 2.5 degrees you'd set the caster at 3.5... same if the truck sits down 1 degree, set caster at 1.5

The old solid axle trucks had roughly 10 degrees caster in them.... 2.5 is too low, I'd get it closer to the max, however the steering may be a bit harder

Best way to see caster is way back when we used to modify our bicycles with longer front forks.... VERY stable but harder to steer, opposite for short forks, easy to steer but very unstable

edit: I don't know what state you live in but here in Fl we have crowned roads, if same where you are add a bit more camber to L side and add a bit more caster to R side

They're SUPPOSED to account for the angle the truck is sitting at then adjust the caster accordingly, no matter if truck is stock,leveled or lifted

IE you have 2.5 in each side but the frame is 1 degree up in the rear, to get an actual 2.5 degrees you'd set the caster at 3.5... same if the truck sits down 1 degree, set caster at 1.5

The old solid axle trucks had roughly 10 degrees caster in them.... 2.5 is too low, I'd get it closer to the max, however the steering may be a bit harder

edit: I don't know what state you live in but here in Fl we have crowned roads, if same where you are add a bit more camber to L side and add a bit more caster to R side

Thanks for the info. Is the alignment machine at dealers suppose to account for height or levelness of truck, if so, is that info punched in by the tech or does the machine get a rough estimate based upon a certain measure point on the truck. I'm out here in Southern California so we do have some crowned roads.

Castor is a measurement to the road, so technically the machine adjusts for a leveled truck because the road is still level ;). Lets just say you 3.5 degrees before you leveled and you changed the chassis angle by 1 degree, you would then end up with 4.5 degrees because you would be rotating the spindle back not forwards. The thing is the chassis angle is the least of your worries. The suspension geometry moves around so much as the suspension moves through it's motions that it's basically like starting from scratch every time you change the ride height.

You can see right on your sheet that the castor range is 3.5-5.5 so you are under that range. You'll notice a difference if you can get to the high range of that scale but i doubt you have enough adjustment left in the bolts if they have your camber as close as they do. With the limited adjustment ability GM put into these chassis alignment is a compromise any time you get away from the factory ride height.

You'll never get 10 degrees of castor out of a modern independent suspension. The OEM's like to stay away from it as Joe Smoe public doesn't like his steering wheel pushing back at him in a turn. Even the corvette only has 7 degrees of castor so it surprises me that GM would allow 5.5 degrees on the trucks.

You can see right on your sheet that the castor range is 3.5-5.5 so you are under that range. You'll notice a difference if you can get to the high range of that scale but i doubt you have enough adjustment left in the bolts if they have your camber as close as they do. With the limited adjustment ability GM put into these chassis alignment is a compromise any time you get away from the factory ride height.


Thanks LMM_Guy. I will admit that for the longest time I was a BIG Jeep guy where all I had to deal with were solid axels. I've no novice when it comes to working on vehicles and understand how things work, but sometimes I look at all the possible adjustment points on the front suspension of my truck and I just say.....WTF. I understand that castor is the angle at which the spindle is laid back, but on our trucks, where is the actual adjustment point, or what is the method. Not that I'm going to fiddle with it, I'm just curious to see how much adjustment is left before I take it back on Friday for the dealer to take a look at it again.

So, a week ago I replaced both the pitman and idler arm with GM parts. Immediately I noticed that the steering became noticeably "easier". Here's what I mean. Replacing the idler and pitman arm made a huge difference in "tightness" of my front suspension as I don't get the slap in the steering wheel when I'm going into a turn such as a freeway on ramp, but now my steering is VERY sensitive to inputs from the steering wheel. It's rather scary driving on the freeway as the slightest move on the steering wheel causes my truck to veer ever so slightly. I tightned everything on my truck when I was done, and re-tightned everything once again to make sure I didn't forget anything. I had the Cognito braces on before replacing the pitman and idler, and I put them back on after replacing both parts. I took it in to have it aligned so the picture you see below is my printout. Any recommendations? I really need to figure this out, it's driving me nuts.

http://img.photobucket.com/albums/v296/crazyjeeper/Link%20Junk/IMG-1.jpg

Well, since you're in the area, I would recommend you call John at Accurate Alignment in Orange, CA. They are located on Batavia Ave just South of Katella. They did my truck and it is perfect.

Well, since you're in the area, I would recommend you call John at Accurate Alignment in Orange, CA. They are located on Batavia Ave just South of Katella. They did my truck and it is perfect.


Awesome, I will give them a call today. First I'm going to take it back to Selman to see what they can do first since I'm still within 30 days. If nothing changes, then I will take it to Accurate Alignment. Do you know if they use a machine or do it all manually?

casters adjusted the same spot as camber is adjusted the upper control arm rear bolts most likely you will find that they cant adjust caster much more i have seen when you adjust your t-bars it brings both camber/caster out to were when you adjust it back to specs its at its max adjustment.

Is your truck leveled? if so how? uca keyes how much is it lifted? There is minimal castor in your front end causing it to wander a bit and become unstable at higher speeds. 1 degree makes a huge difference in handling

once i got my truck to the hieght i liked, i had it aligned with the spec for a 01-04 SS silverado and it handles MUCH better than stock.

FYI - to adjust both caster and camber on these trucks, the bolts where the a-arms mount to the frame have to be loosen'd up and inside there is a offset washer/cam that allows the a-arm to be moved closer to or away from the the frame. by moving the raer bolt towards the frame and the front one away from the frame you will increase caster, but will also change camber as well, so you have to watch the angles and check both.

Is your truck leveled? if so how? uca keyes how much is it lifted? There is minimal castor in your front end causing it to wander a bit and become unstable at higher speeds. 1 degree makes a huge difference in handling


I have 8 turns on the torsion bar bolts on both sides. I'm not sure what that equates to on lift amount.

What I like to do is set the suspension up for max castor....meaing that the rear upper arm mount is all the way to the chassis and the front mount is all the way out. This will move the upper ball joint as far back as you can get. Then check and see what your castor and camber settings are. I first even up the castor or add a slight amount to the passenger side if your roads are crowned. Then see how bad the camber is, if it's way negative or positive you have no choice but to trade castor for camber. On a street driven truck I like anything between 0 and -1 degree. On our trucks camber is not near as critical as it would be on a wide tired sports car. Really camber is just going to be affecting tire wear for our application. Castor on the other hand really changes how the truck feels.

I do my own alignments with tape measures and a 150$ castor camber guage you an get from any circle track supplier. I've never been able to find a decent alignment shop in my area so I've done it myself for years. I'm also into road racing so it's my hobby.

i dont know how many guys are running "wide tread" tires, but it seams alot are into 285 to 315 range, thats pretty wide for a car or truck. so yes camber is important for these trucks