Idler arms and pitman arm

[dancam]

How many idler arms and pitman arms does a 2001 chevy blazer have and how hard would it be to change them

[TCGrove]

There's one of each. The Pitman arm attaches to the steering box. The Idler arm is on the other side of the steering shaft. You can go to Autozone website and pull up the parts to get an idea of what you're looking at. As for difficulty...it's not the easiest job, but you can do it. It really depends on your ability and tools. The only problem I really had was having to re-adjust the steering tension when I was done. The steering wheel didn't want to go to center by itself. There's a little bolt with a locking allen screw in it on the steering box I had to loosen (or adjust). Also, if you do it, keep everything in place when you swap them out. Don't move the steering wheel or anything.

[old_master]

If you make sure the wheels are straight ahead when you torque all of the fasteners, the steering wheel will return to center, provided wheel alignment is correct. Whatever position the wheels are in when you torque the fasteners, is the position the wheels will want to return to. (All steering linkage parts develop a memory when you torque them, including ball joints.)

As for the gear box adjustment, you might want to read this: http://www.partsmike.com/tech-help/saginaw-adj/

[Cruize]

So how exactly do these components development a memory?

My steering wheel is off center after changing inner and out tie-rod ends on both sides and the idler arm. After reading about the "memory", I set my wheels straight ahead, loosened the idler arm mounting bolts to the frame (did not loosen the ball joint at the steering arm) and re-tightened and retorqued. It didn't make a difference. I didn't loosen and retighten the tie-rods. Maybe I should have. What do I do now? Disassemble everything, set the steering wheel straight, set the wheels straight, and then tighten everything?

Thanks.

[old_master]

Ball joints, tie rod ends and where the idler arm connects to the center link, all use a ball and socket mechanism to allow for movement when you're driving. When the fasteners are torqued, the joints bind, (normal). Whenever the steering wheel is moved, the steering linkage will tend to return to the position that the joints were torqued in, hence the term "memory steer". If caster is set too low, the vehicle will wander and require constant correction to keep it in a straight line while driving. This is sometimes misdiagnosed as memory steer.

Hopefully this will answer your last question, then get a wheel alignment


The steering wheel being off center is to be expected if you don't have an alignment done after replacing any steering linkage parts. The steering gear has a center point. There is a high point on the gears that cause them to bind very slightly, (normal). When adjusting toe, the steering gear, (and hopefully the steering wheel), must be centered and locked in position. With S & T body vehicles, the steering shaft is NOT keyed so its possible that someone removed the steering wheel and did not install it correctly. When the wheels are centered and locked in the straight ahead position, toe can be checked and adjusted. Adjusting the toe to specification will center the steering wheel also, if it's done correctly.

When replacing the idler arm, the center link must be level with the frame of the vehicle when the idler arm mounting bolts are torqued to the frame. The holes in the frame are slightly oversize to allow for this adjustment. Those bolts have nothing to do with memory steer, the connection to the center link DOES. If the center link is not level when installed, the vehicle will encounter "bump steer". Bump steer is defined as the vehicle will change direction on a curve, over a bump, without driver input on the steering shaft. In other words, you're going around a curve, holding the steering wheel steady, the vehicle goes over a bump in the road and the vehicle will feel like it's "jumping sideways". Steering linkage and wheel alignment both have to do with geometry, if it's not symetrical, you're gonna have a problem.

This link goes into detail about several problems that can be encountered with steering and suspension: http://www.aa1car.com/library/steerpul.htm

[Cruize]

Thanks for the explanation. But before I get an alignment, I need to get my ride height problem fixed. That's the topic of another post I started today. Don't worry, I only put about 20 miles on the truck since I replaced the steering parts.

The truck seems to track straight, but the steering wheel is off center. If the alignment shop locks the steering wheel in the center position (assuming it lines up with the steering gear center point) and they align the tires via the tie rod ends, won't the truck want to pull if it has "memory" from the ball and socket joints being torqued in an off center wheel position?

If I understand you correctly, I should remove the parts I changed, center the wheel / steering gear, install and torque the idler arm, install and torque the inner tie-rods, install and torque the outer tie-rods, then get an alignment?

[old_master]

Memory steer is not a pull, drift, or wander. Check the link in post #5 under "memory steer". Alignment will not correct memory steer. There are many things that will cause a pull, drift or wander. The most common are cuased by incorrect adjustments to front chassis ride height, camber and/or caster, and tires.

" If I understand you correctly, I should remove the parts I changed, center the wheel / steering gear, install and torque the idler arm, install and torque the inner tie-rods, install and torque the outer tie-rods, then get an alignment?"

You are correct.

[Rimtid]

I replaced my pitman arm on 2001 chevy s10 4 wd. I am not a mechanic but do work on my truck to save money. After replacing the pitman arm my steering wheel is off center to the right. I had the steering wheel key locked straight but not strapped down. The off center I think is because I broke pitman arm loose with pickle fork and sledge. I will be replacing idler arm this weekend and make tie rod adjustments after that.

[old_master]

Originally Posted by Rimtid

I replaced my pitman arm on 2001 chevy s10 4 wd. I am not a mechanic but do work on my truck to save money. After replacing the pitman arm my steering wheel is off center to the right. I had the steering wheel key locked straight but not strapped down. The off center I think is because I broke pitman arm loose with pickle fork and sledge. I will be replacing idler arm this weekend and make tie rod adjustments after that.

After replacing the pitman arm or idler arm, the center link might not be level in the vehicle. This will cause bump steer, and toe will not be within spec. See "bump steer" in the link in post #5. With the wheels straight ahead, the distance from the inner tie rod end studs up to the frame, left and right must be within 1/16" of each other. It is adjusted by loosening the idler arm mounting bolts and move the idler arm up or down as necessary, then torque the mounting bolts.

A pickle fork should never be used to remove the pitman arm. It can, (and usually does) do permanent damage to the steering gear. Always use a pitman arm puller.

[j cAT]

Originally Posted by Rimtid

I replaced my pitman arm on 2001 chevy s10 4 wd. I am not a mechanic but do work on my truck to save money. After replacing the pitman arm my steering wheel is off center to the right. I had the steering wheel key locked straight but not strapped down. The off center I think is because I broke pitman arm loose with pickle fork and sledge. I will be replacing idler arm this weekend and make tie rod adjustments after that.

hopefully you did not damage the box . as was mentioned a puller is used and is cheap tool or you can borrow one at an auto part store. on the tie rods use a puller is best not too much hammering to break free. use a penetrating oil a few days before working it. clean and apply product.
my guess is you are off on the install of the pitman arm which is why the steering is off... installing the idler arm in the same position is required but not much movement with that. this model year is an idler arm/pitman arm regular job..

use a quality lithium based grease at every oil change on all fittings.

when done center the steering wheel and using a line from the rear to front adjust the tie rods so the fwd portion of the rim on the front tires is in about 1/4 inch. then get an alignment if necessary.