Lower Control Arm

[Petey]

Brought it in for a tire rotation, alignment, and oil change today and they found a rotted lower control arm. It's cracked and starting to open. Yes it was a scary ride home know this even though I just did 500 miles with last weekend. Other then the wheel being 5-10 deg to the left(not pulling though) there are no other signs of it.


I'm looking at Moog from Advanced, actually cheaper than Rock. but do I have the 16mm sway bar like stud? Its been a while since I did them and don't remember.

06 LT 4.2 SWB

 

[djthumper]

For an 06 there should only be one choice.

 

[Petey]

I ordered a set of Moogs from advanced and waiting for them to come in. The ones they show online have grease fittings on them (I hoping they didn't mix up the pictures with the Driveworks ones). Is it worth sending them back and getting a set of Duralasts from AZ(They have them in stock at the store), or even getting a set of BECK/ARNLEY from Rock and waiting for them to ship.

What is the best way to swap them out? I am changing the brackets too.

Separate the tie-rod?
Separate the arm from the bracket or take it as one?
Someone on here said something about the hub as to be taken out to get clearance for the lower ball joint stud to clear the knuckle. Is this true? (I have a 4wd)

 

[Petey]

Any tips?

 

[Sparky]

If you're doing LCAs you need to disconnect the lower ball joint, sway link, strut yoke, and of course the bracket from the frame. You could probably keep the arm on the bracket.

I do not remember if we had to pull the hub from mine to disconnect the lower ball joint. I don't think we did...

 

[Hypnotoad]

Going through this right now myself. The Trailblazer is out in the garage torn down as we speak. I'm not sure what can stay and what has to be removed for the swap, since I'm changing just about everything.

Yes, separate the tie rod.

I've done this a couple times now. I don't have to remove the hub. I remove the whole knuckle. I separated the knuckle from the upper ball joint and am able to maneuver the knuckle from the drive shaft (not easy, but possible). Then, I'm able to support the bottom of the lower control arm with a floor jack and hit the knuckle off the lower ball joint.

You'll also need to disconnect the struts and sway bar links. The struts come off the lower control arm very easy with a pitman arm puller. As for the sway bar links, they've always been a pain in the ass for me since I live in Minnesota. They always rust up and I usually end up cutting them off and replacing.

Take the lower control arm and bracket together. It's held to the frame by 3 bolts from the bottom side. Remove them and pull it out. Try to put the new one back the same way the old one came out. You'll need an alignment afterwards.

 

[Petey]

Going through this right now myself. The Trailblazer is out in the garage torn down as we speak. I'm not sure what can stay and what has to be removed for the swap, since I'm changing just about everything.

Yes, separate the tie rod.

I've done this a couple times now. I don't have to remove the hub. I remove the whole knuckle. I separated the knuckle from the upper ball joint and am able to maneuver the knuckle from the drive shaft (not easy, but possible). Then, I'm able to support the bottom of the lower control arm with a floor jack and hit the knuckle off the lower ball joint.

You'll also need to disconnect the struts and sway bar links. The struts come off the lower control arm very easy with a pitman arm puller. As for the sway bar links, they've always been a pain in the ass for me since I live in Minnesota. They always rust up and I usually end up cutting them off and replacing.

Take the lower control arm and bracket together. It's held to the frame by 3 bolts from the bottom side. Remove them and pull it out. Try to put the new one back the same way the old one came out. You'll need an alignment afterwards.

Thanks!

I did the upper Ball Joint about 10k ago so I was not planning on taking the whole knuckle off the truck. I was just not sure if there is enough clearance under the CV joint to get the lower ball joint stud out of the knuckle. The sway bar links are at most 3 years old, so I'm hoping they don't put up that much of a fight. The struts are original so they may fight.

 

[Petey]

update:

The Moogs now have a serviceable B.J.

And here is what my old one looked like


If you look at the first picture you can kinda see the metal fatigue line appearing on the top.

 

[Reprise]

I didn't see the fatigue line in the first pic...but looking at the second, I didn't need to. Wow.

How hard did you find it to torque the new ones down? I took one look at those bolts on the bracket and decided to wait a bit (mine are preventative maint only; nothing like yours were...that is scary looking, tbh). Got mine from Rock - felt sorry for the UPS guy walking the box up to my door!

I know I'm going to have to use / figure out some kind of torque multiplier to go along with my 1/2" torque wrench (longer bar over the handle of the wrench, etc.), as it only goes to 250 ft/lb, and I know the one bolt is higher than that (295, IIRC)

 

[Petey]

I didn't see the fatigue line in the first pic...but looking at the second, I didn't need to. Wow.

How hard did you find it to torque the new ones down? I took one look at those bolts on the bracket and decided to wait a bit (mine are preventative maint only; nothing like yours were...that is scary looking, tbh). Got mine from Rock - felt sorry for the UPS guy walking the box up to my door!

I know I'm going to have to use / figure out some kind of torque multiplier to go along with my 1/2" torque wrench (longer bar over the handle of the wrench, etc.), as it only goes to 250 ft/lb, and I know the one bolt is higher than that (295, IIRC)

Yeah I had my 1/2 torque wrench maxed out at 250(not bad getting to 250 though just braced myself on the chassis and pulled), then I drove it right in for an alignment. To break em free I had a foot long pipe over 1/2 breaker bar.

 

[Sparky]

Wow. Somehow my rustbucket 02 never got like that on the arms even though the frame rotted away.

 

[Mooseman]

And this is an '06? Wow! My rusty '02 never had that on the original arms. Good thing it was caught.

 

[Petey]

And this is an '06? Wow! My rusty '02 never had that on the original arms. Good thing it was caught.

Believe it or not rust is not too bad on the frame. The right control arm is fine also it was just the left. But now I'll be keeping a closer eye on things under there.

 

[Mooseman]

It must have been made with recycled Mazdas.