I have been hearing a rattling sound in front end, so when I went underneath to inspect I noticed the what I believe is the idler arm is loose with an up and down movement. It is tight where it is bolted on. The steering is good, and is not loose feeling, but I hear it rattling when I go over bumps. Any advise would be appreciated.

 

the idler arm has a ball joint in it, it cold be worn out. if its "loose" replace it

 

I have ramps and tools. Just never replaced one before. Anything I should know?

 

Just a simple replacement - you'll need to beat the old end out of the centerlink, like beating out a tie rod end. Tightening the bolt on the new one will seat it, like a tie rod end.

 

I'll go for it. Is beating it loose hard on the tie rods? Funny thing, I had it in storage all winter. It started rattling this spring. Go figure.

 

If you haven't replaced parts already, you might consider the following kit from Spohn:

http://www.spohn.net/shop/1982-1992-...GM-F-Body.html

JamesC

 

Make sure you mark the spot where it was on the "frame", so you can put the new one back EXACTLY where the old one was. For the steering to work right, the axis of rotation of its "upper" joint, must be parallel to and at exactly the same height as, the axis of the pitman arm over on the steering gearbox. Get it as close as you can, then take the car in for an alignment.

While that's the part that usually wears out first, if it's wore out, then all the rest of the joints in that system probably are too. It's SUPER EEEEEZIE to change them all out at once. Unbolt the idler from the "frame" after scribing its shape on the "frame" around it; and remove the nuts that hold the outer tie rod ends to the spindles, and the one that holds the center link to the pitman arm. Lay all that on the ground. Assemble a new center link, all 4 new rod ends, new adjuster sleeves, and a new idler arm, to EXACTLY match the old ones (length). Assemble to the car. Drive to alignment shop. You might think your steering is OK now, but you won't believe how much better it will be after that.

BTW, don't have it aligned to stock specs; they are STUPID wrong. Instead, have them set the caster to about 4 - 4½° positive, and the camber to about 1 - 1½° negative, with a split of about ½° higher on both on the left side; and the toe to about .030" - .050" inward.

 

You can get all of the tools you need from Autozone or one of the other chains in their loaner program. You can use either a puller or a pickle fork to remove the old one. The puller is less likely to damage any parts.

When re-installing the idler arm, it's important to get it at the correct height. It should be even with the pitman arm off the steering box, both measured from a common point on the frame. Note that the idler arm bolts go into slots to allow this adjustment.

You'll have to grease the fittings on the new one and might as well grease all of the other fittings while you're there. A gun is pretty cheap.

An alignment is not required when replacing just the idler arm, but if you get into replacing anything else under there you should consider replacing all. An alignment's going to run +$50 which is a large fraction of the cost of all new pieces. So check everything while you're under there.

 

If I am having up and down movement with the idler arm then It must be affecting the alignment when driving right? So marking on the frame.... would it put the position of the idler arm back to where its supposed to be, or is it too late for that? I am also considering replacing the tie rods after reading the advice in this thread. I religiously grease everything in my Camaros, and the joints seem good. Are there any tell tail signs of bad rod end joints I should be aware of?

 

You might double check, but I'd be surprised if the idler arm itself has moved from its bolted position, so scribing it where it is should be fine.

JamesC

 

The bolts are tight, and there is no movement where it is bolted. It moves at the joint just below where it is bolted. If it is sagging below where it should be is what concerns me.

 

Scribing the location may be alright although you may want to verify that the new piece has the same dimensions as the one that was removed. Keep in mind that you're also making the assumption that if it was ever replaced in the past (I'd say a middling/fair probability) that it was installed correctly then.

If the arm is moving up and down, it's likely worn at the joint between the swing arm and the mount. Highly unlikely the two bolts mounting it to the frame are loose.

While it's loose it will allow the alignment to slightly change as it moves vertically, up and down. If you'll note how the tie-rods go from the centerlink to the spindles, you'll see that vertical movement of the end of the centerlink-where it attaches to the idler arm-will slightly change the toe. You want to install it at the same height as the old one to keep the toe settings-assuming they were correct. It needs to be at same height as the pitman arm to maintain proper geometry.

 

OK, the same height as the pitman arm. Makes sense. Before I get going on this, how do I measure exactly the pitman arm height assuming eye balling wouldn't be exacting?

 

Height, and front-to-rear for that matter, is not too hard; you can set it using the LCA bolt as your reference. With the wheels straight, both inner rod ends should be in the same relationship to the bolts.

The harder thing is making its axis parallel to the pitman shaft in the gearbox. I'm not really sure of a good way to do that, other than watch the swing of both ends, as somebody turns the wheel from side to side. If it's not parallel then the center link won't stay level from lock to lock.

Yeah the scribing thing isn't always accurate if the outside of the pieces is different. Scribe inside the bolt holes in that case.

 

All this tech advise is helpful. I talked to a friend at Advanced auto, and he told me the holes are not slotted, so marking is not necessary. I will find out tomorrow when I replace the idler arm.

 

He's, um, misinformed.

 

So you know they are slotted?

 

Yes.

JamesC

 

To tell the actual truth, I do NOT know that yours are slotted. I do know that SEVERAL that I've worked on WERE slotted and that the slots are intended to provide room for adjustment. I'm making a small inductive leap from the specific to the universal and that is never without some degree of peril.

 

Less is more.

 

Slots are on the car, not on the idler arm.

 

Yep.

JamesC

 

I just installed the idler arm. I used an impact to get the nuts loose from the frame. I did notice that the holes were slotted. "yep" slotted. Seems to handle tighter, and no rattle. Thanks for the input.

 

Outstanding.

"Morality is the herd instinct in the individual." Nietzche

 

Don't mean to hijack someone else's thread, but I just replaced my idler arm when I redid the front tie rods and brakes, (it was broken). I had the same rattle as the OP. Then, I drove around, across town, and on some rough highway.... And I hear the rattle again. Now, to me, the car seems to ride rougher than my old 85, and I have to be careful on every bump or I feel like I'm going to shatter or break something....

I didn't get a mechanical alignment, the mechanic just did it by hand, but I'm just wondering if I rebroke the damn idler arm?


I'm still pretty new at doing things other than tune-ups, so any opinions would be greatly appreciated

 

You need to get under your car and see for your self. A bad idler arm shouldn't cause your car to ride rough.

 

Yeah, I have to get to my parents driveway to actually be able to get it up in the air. And I didn't mean the idler arm caused the roughness, I was just looking for opinions about it while I was on the topic of suspension and what not

 

I'll try to give the alignment specs the shop gave me on my RS (I'm a little over my head with this stuff). Camber: .6 degrees, Caster: 4.9 degrees. My steering wheel is nice and straight, and It handles very well as it always has for street use. I'll have the IROC done on Friday.