Pitman / Idler arm help needed

[number9]

Guys, I got an '03 4x4 1500 Yukon with about 170K on it (bought it with 36K on it)

Steering system needed a go-thru of course.

I had all 4 ball joints replaced and then I replaced, myself, both wheel hub/bearings, tie-rods and pitman / idler arm, and idler arm bracket and new tires as well. Threaded the new tie-rods to same length as the old ones I pulled out and of course had it lined up after the work was done.

Long story short, it's had bump steer ever since. When you go over a rise / dip and the suspension cycles, as the front rises (suspension extends) it pulls to one side (can't remember which) and then pulls to the other side when the front compresses (suspension compresses).

I've found that with the front skid plate removed and looking through the air dam under the bumper at the centerlink, when comparing it's "levelness" to the swawbar, the crosslink is not level. It's higher on the pass side. Measuring from the concrete floor up to the bottom of the inner tie-rod, the pass side is about 1" higher than the driver side. Also, looking at the tie-rod angles, the pass side looks close to same angle as the A-arm, but the driver side looks almost flat (level).

I had the GM dealership screw up once and put a 1/2-ton idler on my 2500HD and it had same symptoms - so I know even the dealership can have a parts screwup.

The parts I put on it were ACDelco from RockAuto.

Idler Arm # 46C1120A
Idler Arm Bracket # 46C1123A
Pitman Arm # 46C0069A


I stopped at the dealership today and bought the GM Idler Arm/Bracket combo and Pitman Arm to compare to what I've got and see if one is obviously different. They were $340 and the guy said I can return them so I am trying my best to compare them and not get the new ones dirty / greasy in the process.

I'll take some pics and update in a bit, pics are worth 1000 words.


At any rate - if anyone has ran across this before, would happen to have pics of their idler / pitman or could even confirm that the crosslink DOES run level on their truck, it would be a HUGE help.

 

[number9]

Here's the pics.

Showing difference in tie-rod angles (compare tie rod to axle shaft & lower A-arm)



Centerlink at angle, not horizontally level like the swaybar is.



Pitman Arm - ACDelco # 46C0069A



Idler Arm - ACDelco 46C1120A




If anyone with same gen 4x4, 1/2-ton,SUV / truck could confirm their Pitman / Idler looks the same as these and/or their Centerlink is horizontally level or at an angle when compared to the swaybar like in the pics above, it would be a fantastic HUGE help!!

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[Larryjb]

I noticed that some of the splines are still visible between the pitman arm and the steering gear. I've heard that the same situation occurs with Moog pitman arms, although you have ACDelco parts. Could this be related?

Also, what ACDelco line was used? I believe there are at least three lines. One is the original line used at the factory, another is a "professional" line, another is an "Advantage" line. According to your part number, you've got the "Advantage" line which is cheaper.

 

[number9]

Yes, you are correct. I did get the ACDelco Advantage parts (pitman/idler).

The bends in them should be no different, however, the "professional" line may fit all the way up snug on the steering box. I've researched the forums (several) and found tons of discussion on pitman arms fittment and seems consensus across the board is, it is very common and as long as you have threads sticking out of the nut, it's good to go.


That gap now is roughly 3/8", so even IF it would seat 100% of the way up, it still wouldn't get the centerlink level.

I'm hoping someone who has no driveability issues can look at theirs and confirm or deny if the centerlink is at an angle or parallel with the swaybar.

 

[number9]

I'm going to keep updating for anyone that may be following or have this issue and find this thread.

Returned the ($350) GM parts to the dealer yesterday and talked to "their best front end guy". When I asked him if the centerlink is supposed to be level or at an angle, he said he'd never really paid any attention and the discussion really didn't help any.

There was an '05 Tahoe in their lot that I looked at and took pics of. Tie rods on it looked to be at closer angles than mine. Below pic is showing my truck on top.



Something is different between the two, maybe it's due to the ACDelco Advantage Pitman Arm I got not seating far enough up on the gearbox? I don't know.....

I placed an order from GMPartsGiant for the GM Pitman / Idler for $231 shipped. I'm going to try the pitman arm first and see how much better it will seat on the gearbox and what difference it may make.

Something I did notice looking at the pic above, is that my pass side wheel looks to have negative camber, but I'm not sure if that would cause the bumpsteer this truck has. I'm going to get an appointment to have the alignment checked out again before putting the new arms on.

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[mattbta]

Watching your thread...although mine is 2wd, ever since I had the idler/pitman replaced (and subsequently replaced again) I've had horrible steering issues. Front tires squeal when parking, no matter the surface or temperature. Also when making a tight turn maneuver in a lot, the front end hops much like when turning in ice/snow. It eats through tires (outside edges) and I get it aligned every month. Only thing that isn't new on the front end is gearbox, UCA/LCA/balljoints. And multiple shops say there's no slop.

When you say bumpsteer -- is it like a crowhop? I read about that on 4x4 but mine hops like no other and I can't figure it out.

 

[number9]

No, by bump steer I mean when you crest a rise (think roller coaster as exaggerated example) and the front suspension extends, the wheels pull to the left....when you hit the bottom of the dip and the front suspension compresses, the wheels pull to the right. This happens all the while your holding the steering wheel straight. The wheels are steering by the geometry being 'off' as the suspension/steering components move through their range of motion.

Driving on a 2 lane country road is a handful.

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[mattbta]

Understood. I don't think I experience that condition but any unlevel or imperfect part of the road causes my steering wheel to go to either side and then self correct.

 

[Larryjb]

When I put the skid plate back on mine, I'll take a peek at my relay rod (center link). I did a poor man's alignment for the toe today. I can't say I experienced anything like bump steer. I did notice that one wheel had about 1/2 degree, the other side was pretty close to 0 degrees camber. Seems within spec, and it seems to track well. I'll see about paying for an alignment when I get new tires this winter.

How are your shocks? Do you have one side going soft?

Also, check the ball joints that you had replaced. I had one shop that neglected to use a cotter pin on the slotted nut, and didn't torque it down. That caused some very scary handling.

And, of course, double check your own work. If a paid professional will forget to torque something down, I know I can too. The difference is I triple check my own work (perhaps why I take so long doing these jobs).

I hope it works out for you.

Larry

 

[number9]

Thanks Larry, I did have a shop install the ball joints but I did all the other work. I looked them over when I picked it up, but never hurts to confirm again, I'll do that as well as my own work.

Got an app today to get alignment checked so we'll see how bad it's out (I'm sure it is) and what change it makes in condition. Getting a GOOD alignment around here anymore is next to impossible, same can be said for getting a GOOD tire balance job.........I've even considered buying my own balancer....

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