C3500 front spring reinstallation

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Miles B

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I'm doing a front end job on my '00 C3500. I think the last guy bent the lower control arms a little in the press as they were a real pain to get out of and back into the frame pockets. I finally got them back in. Now I need to get the springs in. With all of my cars, I can sit the spring in, lower the hoist a little on the lower arm and then kick the spring into the LCA pocket. This doesn't work with the 25mm wire springs in this thing!

How else is everyone doing it? I tried ordering an OTC 7045B as my other compressor is only good to 19mm wire springs.. it's the hook type. I just use it for Mustangs and stock height Vettes. Unfortunately everywhere is out of the OTC tool and Summit says 28 December estimate! I need to get this thing done.

I really think I only need to compress it about 1.5". By my calculations it's a 1400 lb/in spring.
 

Miles B

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I checked the manual and it says reattach the spindle, then jack the LCA up into the frame. That method has always seemed super sketchy to me, and it's a non starter on this one anyway because those arms just don't want to go into the frame. I have no idea how people guide the arms back into the frame. What do you do, push the jack around? Seems like a recipe for disaster.
 

someotherguy

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Is the manual showing the control arm loose at the frame pockets while raising with the jack, or are you assuming that's what they mean? It seems hard to imagine they would have you jacking a loose control arm (other than attached at the ball joint) up to compress the spring.

I've done plenty with a floor jack, but so far not any 3500's that I can recall, but believe me I do understand the concern. That's a serious spring. When I do the floor jack method I do have the spindle attached at the lower control arm, arm in the frame pockets as well. I leave the upper ball joint loose and guide the spindle up to it as I raise the jack.

With all that said it does seem like needing to compress the spring a little bit would go a long way towards success in the case of a 3500.

Richard
 

Miles B

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Is the manual showing the control arm loose at the frame pockets while raising with the jack, or are you assuming that's what they mean? It seems hard to imagine they would have you jacking a loose control arm (other than attached at the ball joint) up to compress the spring.

I've done plenty with a floor jack, but so far not any 3500's that I can recall, but believe me I do understand the concern. That's a serious spring. When I do the floor jack method I do have the spindle attached at the lower control arm, arm in the frame pockets as well. I leave the upper ball joint loose and guide the spindle up to it as I raise the jack.

With all that said it does seem like needing to compress the spring a little bit would go a long way towards success in the case of a 3500.

Richard

Man I had to read it about 10 times to believe it.

Coil Spring Replacement
Remove or Disconnect
1. Tire and wheel assembly
2. Shock absorber
3. Stabilizer shaft from LCA
Raise the jack to remove tension on the LCA pivot bolts
Secure the spring wtih a chain through the spring and LCA
4. Pivot bolts and nuts
Take the rear pivot bolt out first
Lower the control arm by lowering the jack
When compression is removed from the coil spring, take the chain away
Do not force the LCA and ball joint in order to remove the spring
5. Coil spring

Install or Connect
1. Coil spring and insulator on the LCA
Refer to figure 25 for correct coil spring positioning
Secure spring with chain
Insulator on top
Use J23028-01 to support the LCA
2. The LCA in place on the frame
Guide the LCA into place with a pry bar
3. Pivot bolts and new nuts
Insert and tighten the front bolt first
Remove the chain and jack


LCA bolts should both point to the rear of the vehicle. UCA bolts should both have their heads together.
Looks like that tool sits on top of the jack and pushes on the shells of the LCA bushings.

GM can stick that method so far up their butt. I'm not doing that. I found a place in Australia with the OTC tool rebadged as a T&E brand. Cost me the equivalent of 270 USD but I'm not screwing around with this. I've done plenty of front end jobs on older GM double wishbone suspensions but the springs are 1/3 the rate and half the weight. People stare at me when I see I do them on the hoist with a 8x2 to push the arms closed, and I kick the springs into place. It's never worried me. But I'll be happy to have this tool now and do them all with the 8x2 and a spring that I pre-compress 2 or 3 inches.
 

arrg

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Man I had to read it about 10 times to believe it.

Coil Spring Replacement
Remove or Disconnect
1. Tire and wheel assembly
2. Shock absorber
3. Stabilizer shaft from LCA
Raise the jack to remove tension on the LCA pivot bolts
Secure the spring wtih a chain through the spring and LCA
4. Pivot bolts and nuts
Take the rear pivot bolt out first
Lower the control arm by lowering the jack
When compression is removed from the coil spring, take the chain away
Do not force the LCA and ball joint in order to remove the spring
5. Coil spring

Install or Connect
1. Coil spring and insulator on the LCA
Refer to figure 25 for correct coil spring positioning
Secure spring with chain
Insulator on top
Use J23028-01 to support the LCA
2. The LCA in place on the frame
Guide the LCA into place with a pry bar
3. Pivot bolts and new nuts
Insert and tighten the front bolt first
Remove the chain and jack


LCA bolts should both point to the rear of the vehicle. UCA bolts should both have their heads together.
Looks like that tool sits on top of the jack and pushes on the shells of the LCA bushings.

GM can stick that method so far up their butt. I'm not doing that. I found a place in Australia with the OTC tool rebadged as a T&E brand. Cost me the equivalent of 270 USD but I'm not screwing around with this. I've done plenty of front end jobs on older GM double wishbone suspensions but the springs are 1/3 the rate and half the weight. People stare at me when I see I do them on the hoist with a 8x2 to push the arms closed, and I kick the springs into place. It's never worried me. But I'll be happy to have this tool now and do them all with the 8x2 and a spring that I pre-compress 2 or 3 inches.
I had the same problem you're having when I tried to install new lower arms on mine. There's something about the shape of the frame pocket or the arms that makes the arms easier to install when they're parallel to the floor. I think that's why GM recommends this procedure. I had a hell of a time getting the arms into the frame until I tried it with the arms parallel to the floor. Then they just slipped in. It was one of those "ah ha" moments as to why that GM procedure exists. That said, I still didn't try to install the spring that way, just the lower control arms.
 

someotherguy

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Something else that might help depending on your method. I've had some OEM springs that were tall enough they kept wanting to jump out of the LCA pocket when attempting to jack up the LCA. I have some seriously heavy duty ratchet straps, not some little 1" cheesy ones.. that I'll run the hook towards the opposite side and grab the spring at a middle coil with it and securely ratchet it in so that it can't try to escape. Obviously great care should be taken as this is far from foolproof, but it got me out of a jam a few times.

Richard
 

Andrew7

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I'm doing a front end job on my '00 C3500. I think the last guy bent the lower control arms a little in the press as they were a real pain to get out of and back into the frame pockets. I finally got them back in. Now I need to get the springs in. With all of my cars, I can sit the spring in, lower the hoist a little on the lower arm and then kick the spring into the LCA pocket. This doesn't work with the 25mm wire springs in this thing!

How else is everyone doing it? I tried ordering an OTC 7045B as my other compressor is only good to 19mm wire springs.. it's the hook type. I just use it for Mustangs and stock height Vettes. Unfortunately everywhere is out of the OTC tool and Summit says 28 December estimate! I need to get this thing done.

I really think I only need to compress it about 1.5". By my calculations it's a 1400 lb/in spring.

Yes that’s a problem. It’s hard to find a spring compressor that fits the larger spring size. I ended up using a grinder and cutting off a horseshoe size of the top of the spring! There’s a video about spring height measurements on the Summit Auto site.
 

TAF2003

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Something else that might help depending on your method. I've had some OEM springs that were tall enough they kept wanting to jump out of the LCA pocket when attempting to jack up the LCA. I have some seriously heavy duty ratchet straps, not some little 1" cheesy ones.. that I'll run the hook towards the opposite side and grab the spring at a middle coil with it and securely ratchet it in so that it can't try to escape. Obviously great care should be taken as this is far from foolproof, but it got me out of a jam a few times.

Richard

+1. This is how I did the coil springs on mine.

Held the spring in the upper pocket with the LCA and floor jack. Used the strap to help pull the spring into the LCA pocket as you use floor jack to raise the LCA and compress the spring.

I learned the hard way you need to completely wrap electrical tape around the insulator pad and upper spring so the insulator doesn’t get caught.

It makes quite the sound when the compressed spring finally slips off the edge of the LCA pocket into pocket itself.

The annoying part was the end of the coil getting caught in the shock hole on the LCA as the strap pulled it across.


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SUBURBAN5

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I'm with there with all of you. Very long frustrating nights when I did it. However mine a c1500. What I did was buy a spring compressor and compressed the spring. Just for it to slip off and freaking open in its full position..... so I then tried random crap... however I will say this. Wrap a strap on the spring and control arm and let it come down slowly with the jack under the CA. Installation a lot harder..... what I did is similar to the above.. I left the lower CA bolts loose and pushed up the spring to its seated position. I then pushed the arm up slowly with the jack to start compressing the spring back up but I understand the spring goes crooked and want to shoot out sideways. Plus you have to make sure it's still in its seated position... I actually continued slowly with CAUTION jacked the CA up to where its was close enough to its position. Then I used a small sledge hammer to hit the spring into position.... my spindle was attached to the lower CA btw..

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