I just bought this car this summer G92 option 88 Iroc z vert, I’m having a problem with steering wandering and steering not returning to zero on its own. In my research there is talk about how all aftermarket idler arms are not made with proper geometry and only ACdelco are the ones to use, so I just had a look under the car and my idler arm is stamped with 20231003, I can find zero reference to this number. I will definitely get an acdelco replacement but it’s going to be 4-5 months before I can test drive , winter is setting in here in Quebec. There’s no free play in the linkage or steering box that I can see, not sure how good the alignment is but it doesn’t pull to either side, tires have even wear. I would like to hear your thoughts and ideas. Thanks.

 

thats castor.

Id go get an alignment before i did anything else.
Without knowing the alignment specs, you will be just guessing at things---like this idler

 

As posted above, the problem you describe is the product of incorrect caster adjustment. Your car needs a front-end alignment, especially if front-end components have been replaced.

before doing so though, you'd do well to check all other front-end parts to make sure nothing else is worn out before its trip to the alignment shop.

 

I do agree about having the alignment checked but the car is tucked away in my garage for the winter, i don’t remember what the tread was but it is in this forum about jobber idler arms not being correct and it makes alot of sense, at least to me it does,,the comparison between the 2 show the different angles. The thread was from quite awhile ago and there was a lot of discussion about this issue, I’ll try to find the link to the thread if anyone is interested.

 

37 yo car, remove every piece of the steering/suspension and after looking at it closely replace what is needed and then align the front end. Good chance most of it will need replacing if you want it to work like new. Also inspect every place that anything bolts to the body for stress cracks or broken welds. They are known to crack at the steering box area and the fronts flex which is why they made the wonder bar.

 

Currently the majority of idler arms are the same, AC Delco is identical to a Moog, Proforged or other major brands. Years ago (10 years or more) the AC Delco was different, but that is no longer the case, I agree with others that the caster or other alignment issues is the cause of your problem over the idler arm. Some of the cheaper brands have the curve where the idler arm mounts to the frame off but from your picture that is not the case with what's on your car.

 

Thanks for the input, guess I’ll have to wait for warmer weather and get the alignment checked.

 

check all of your suspension pieces first, or ensure they carefully do.

would suck to get it aligned then find you have a piece/part that once replaced, requires another alignment.

pay particular attention to your ball joints, they can bind and cause a lack of return. they can also articulate freely when the wheel is lifted but bind when the tire is loaded. if you can, get the alignment shop to disconnect the tie rods and check that the wheels move freely while loaded. might be a hard sell though.