Lower Control Arm Bushings

[Big T]

I've replaced these bushings on my son's '94 K2500 Suburban. I could never get the control arms off the torsion bars and ended up pulling the entire assembly - control arms, torsion bars and rear cross member - as a complete unit and popped the bushings out with a bottle jack. I would like to replace these bushings on my '99 and was wondering if it would be possible to leave the arms on the truck and drop them enough to pop the bushings out? I just can't remember enough from when I did this job and it was only back in 2013.

This is one of those jobs you only do once on these trucks and I'm going to be in there when I do the GMT 800 brake conversion. My current bushings are cracked and I can pull small pieces of rubber off the outer edge, though I can't detect looseness in the control arms. Moog bushings have been ordered.

 

[THEFERMANATOR]

Not of much help as I haven't done any in the forged arms yet, only the stamped arms.

 

[Big T]

Likewise, only stamped steel arms for me. But the real question is whether I can lower the arms enough, while still attaché to the torsion bars, to create access to pop the bushings out and install new ones. Should be the same whether stamped or forged.

 

[FellowTraveler]

On my 99 Burb w/forged control arms I had to drop the frt/diff to get out one of the control arm bolts then used a press to remove and replace the bushings.

 

[Big T]

On my 99 Burb w/forged control arms I had to drop the frt/diff to get out one of the control arm bolts then used a press to remove and replace the bushings.

Yeah I recall having to lower the front diff on the '94 to remove the rear bolt on the driver's side. When you say "press" is that similar to using a bottle Jack held in place with chain?

 

[Will L.]

When I didnt have a press or big vice handy, I used a small mapp torch to cook the rubber a bit, then it pops out. Now a saw all metal Blade fits in there nice to make relief cuts on opposite side. The chisel pops it out. 10 minutes each.

Otherwise harbor freight has there 2 big presses on sale now.

 

[THEFERMANATOR]

It IS possible to get the rear control arm bolts out without dropping the diff, but it requires rem9ving the torsion bars from the control arms to do it. Removing my diff is NOT an easy task(requires taking the engine loose, raising it up with a cherry picker, then I can get the upper diff bolts out), so if you remove the torsion bars completely, you can grind a flat on the end of the control arm bolts, remove the front bolts, drive the bolts out tight, cock the control arm in the mount, then you can take them all the way out.

And I ended up having to use my press to get the rear lower control arm bushings out. The front ones are dented over, so you have to use a hammer and punch there, then I used a large ball joint press on them, but the rears were just to long for it. Pressed them out, then used the ball joint press to drive the new ones in.

 

[Big T]

When I didnt have a press or big vice handy, I used a small mapp torch to cook the rubber a bit, then it pops out. Now a saw all metal Blade fits in there nice to make relief cuts on opposite side. The chisel pops it out. 10 minutes each.

Otherwise harbor freight has there 2 big presses on sale now.

I just looked at those presses and they would require complete removal of the control arms. As noted, I anticipate being unable to remove the control arms from the torsion bars. I would prefer to avoid removing the whole assembly inclusive of the cross member.

As for the differential, maybe I use this opportunity to swap in the differential from the '95 wreck which had a 4.10 rear axle. Then I keep the axle I just bough for Colby's '94 and swap that in, completing my conversion to 4.10. I'm told it will be hard to find a GMT 800 era 14 bolt, 10.5" full floater in 3.73 ratio.

I guess this is one I'll deal with in increments. Thankfully, it's not my daily driver and thus can be down.

 

[FellowTraveler]

It IS possible to get the rear control arm bolts out without dropping the diff, but it requires rem9ving the torsion bars from the control arms to do it. Removing my diff is NOT an easy task(requires taking the engine loose, raising it up with a cherry picker, then I can get the upper diff bolts out), so if you remove the torsion bars completely, you can grind a flat on the end of the control arm bolts, remove the front bolts, drive the bolts out tight, cock the control arm in the mount, then you can take them all the way out.

And I ended up having to use my press to get the rear lower control arm bushings out. The front ones are dented over, so you have to use a hammer and punch there, then I used a large ball joint press on them, but the rears were just to long for it. Pressed them out, then used the ball joint press to drive the new ones in.

I've pulled the front diff many times to run different gear-sets from 3.42, 3.73 & back to the 4.10's so dropping it was easy for me, I do see your way is a good idea too....

 

[THEFERMANATOR]

I've pulled the front diff many times to run different gear-sets from 3.42, 3.73 & back to the 4.10's so dropping it was easy for me, I do see your way is a good idea too....

Once you drop a DURAMAX in, dropping the front diff is NOT easy. I have to use a cherry picker to jack the drivers side of the engine up almostt 3 inches so I can get the upper drivers side mount bolt out. Needless to say I do NOT want to do that if I don't have to.

 

[Fitzmeister59]

I removed my lower control arms without removing the front diff. I cut the head off of the back bolt and replaced it with a new one inserted from the back with the nut in front. I removed the control arm with the torsion bar in it, pulling the torsion bar out of the key in the cross member ( after loosening the adjusting bolt). I used urethane bushings, requiring me to burn out the old rubber and reusing the outer cup of the old bushing. I would also replace the ball joint while you have the arm out. Might as well do the upper bushings and ball joints as well.

 

[FellowTraveler]

I removed my lower control arms without removing the front diff. I cut the head off of the back bolt and replaced it with a new one inserted from the back with the nut in front. I removed the control arm with the torsion bar in it, pulling the torsion bar out of the key in the cross member ( after loosening the adjusting bolt). I used urethane bushings, requiring me to burn out the old rubber and reusing the outer cup of the old bushing. I would also replace the ball joint while you have the arm out. Might as well do the upper bushings and ball joints as well.

There is a difference in the front 9.25 front differential cases "being those newer versions with the additional pinion oiling, case reinforcement to the yoke and additional cooling fins are slightly bigger and stronger than the earlier 9.25" cases."

 

[Big T]

I removed my lower control arms without removing the front diff. I cut the head off of the back bolt and replaced it with a new one inserted from the back with the nut in front. I removed the control arm with the torsion bar in it, pulling the torsion bar out of the key in the cross member ( after loosening the adjusting bolt). I used urethane bushings, requiring me to burn out the old rubber and reusing the outer cup of the old bushing. I would also replace the ball joint while you have the arm out. Might as well do the upper bushings and ball joints as well.

I ordered Moog Bushings and they are barbell shaped with no outer cup.