Build thread for the 72 GMC, finally. Thanks John!

Alan Cesar wrote:

tuna55 wrote: While the technically-minded among you try to figure out other potential solutions to the fuel sender issue, perhaps the more silly folks can come up with an excellent souvenir to send the folks who pitched in on the springs. Do you guys want pieces of the busted up spring? Hunks of old Bondo and rust? I don't have any spare locks of hair, but I could spare a few inches of MIG wire.

When you have names and addresses, send them to me, too. I'll get a little swag on the way from GRM.

There seem to have been a few more contributions over the weekend (I was out of town, working on our LeMons Car). I'll get the names and addresses into a spreadsheet and email it to Tuna.

The big fish has enough chores in his life...lets just let him off the need t thank a bunch of people one at a time and settle for a well documented spring install post.

NOHOME wrote: The big fish has enough chores in his life...lets just let him off the need t thank a bunch of people one at a time and settle for a well documented spring install post.

Tuna asked me for the list. How could I refuse such a request?

is a great summary of this entire thread

You guys are way too kind. I appreciate it, though. I really do.

Tonight was... interesting. Let's start with a brief letter that I wanted to share with you. I presented it to her tonight.

I'll call it 'Cheater'.

Did you think I wouldn't find out? I've been with you a long time. I've never been as close before, or for as long. I suppose I should have expected something like this. I know it's in your past, and what has happened has happened, even if it was before me, but it's still disturbing. How much can I trust now, of your past? How much can I touch without the knowledge that someone has been there first? I realize that you're older and more experienced, but you never mentioned any of this before. It's good that I have good friends who have been able to take care of my needs regardless of your conflicts. When the other leaf spring came apart so easily, I should have known. The passenger side was stuck. As I ground the heads off the center pins I remembered that I had a wrench on the bolt on the drivers side. That's because it was a bolt. The broken spring probably broke because some jerk put it together wrong. Nice. I feel betrayed.

I have a lot going on in the rear suspension. I am adding a swaybar, lowering the ride height, splaying and 'uprighting' the dampers, and raising the front bracket. It's difficult, because it all goes together, well, together. At an hour a night or so, assigning all of these things a place to live can be... difficult. It turns out my damper brackets that were tacked on the axle tube were in the wrong spot, and perhaps designed wrong. The upper damper mount on the passenger side is wrong. The front brackets may be too far forward depending on the dimensions of the new springs, and everything has to move, if only slightly.

I re-installed the leaf springs with just the main spring an the overload, so that I could easily get to full droop and full compression and yet locate the rear axle properly. It was about this time I noticed that the U bolts and corresponding brackets SUCK. Majorly. I need to replace at least the brackets. It's odd that they are stock GM, but seem to not be totally happy. The rear end is from another truck, though, so likely the spring perches are not jiving well with the other hardware. I now need to go bracket hunting, and at least one of the U bolts has ruined threads. I found this out by smashing my fingers against the frame. It's that dull 'smash' where your finger just feels like pulp and bleeds only a little. It's awesome.

Let's take a look at the new swaybar mounts. I made them out of nylon.

And by 'nylon', I mean 'zip ties'. I am going to weld on spring perches and drill them for the bushings and brackets. Here are the side brackets.

Nifty, eh?

The swaybar is "installed" per the donor, a 96 or so Suburban.

That actually fits. So good there.

Here are the damper mounts, with the dampers just hanging all-out, and the axle set a touch above ride height.

Here is one at near full-droop. This is the drivers side. This upper mount is right where I want it.

I'll need to make a new mount somewhere above the swaybar, but it also has to avoid interfering with the swaybars bend.

Here is the passenger side.

Notice how much more upright it is. There are two holes in this bracket, and the stud only sticks out of one, and doesn't appear to easily move from one to the other. My measurements were based on the other hole, and I am not certain of the best way to change that just now.

Here is where it ought to be.

I have a lot to do before those springs get here.

More progress! Nice!

I am looking for some round U bolts to replace my crappy square ones (because as an engineer a 90 degree bend in an important bolt scares me, not to mention my disgust at the way the nuts don't easily thread on and the crappy GM bracket) which means I need some top plates with 2 1/4" width rather than 2 1/2". As a last resort I can weld up the holes and drill new ones, but I am hoping to avoid that.

Do you guys like my nylon swaybar brackets?

when i first read your post thins morning, my stomach dropped and i began praying for your marriage. took a few minutes for it to sink in that you were taking about leaft springs.

i need to NOT read this thread prior to my first cup of coffee.....

and i like the zip ties. might need to double them up for strength. im thinking they may pull out under hard cornereing.

As far as the shock bracket is concerned, I would cut it right down the middle between the two bolt holes. Then I would weld the front half to the back of the rear part. This puts the stud up front and keeps the integrity of the stud mount that was originally designed by some well paid engineer.

Will need to add something in the middle to make the spacing work out or maybe spin the front piece around and space the cut.

drive or cut the stud off and go to napa and get a new shock mounting stud

napa # NOE 6501100

http://www.napaonline.com/Catalog/Result.aspx?Ntt%3d650-1100%26Ntk%3dKeyword%26Nty%3d1%26Dn%3d0%26D%3d650-1100%26Dk%3d1%26Dp%3d3%26N%3d0

In reply to solfly:

Bought some from Rubicon Express a few minutes ago. It's ok, though. It may sound od, but it's WAY easier to click a button and play with other stuff in the two days Amazon Prime takes than it is to try and get to an actual store on a weekday (or a weekend for that matter). They looked pretty rockin'.

I'll probably do both sides just to be sure, as these were not particularly strong from the factory, and then perhaps tack weld from the backside.

Dusterbd13 wrote: when i first read your post thins morning, my stomach dropped and i began praying for your marriage. took a few minutes for it to sink in that you were taking about leaft springs.

HA! Yeah, that was the general idea. I was listening to metal last night and a bit angry at the mess the rear suspension was in, so I decided to be mischievous instead of angry. Plus, the truck cheated on me! When I am done, though, there won't be a bolt left as GM put it. In fact, I am rapidly closing in on that point.

Mmmmmm...... metal.

Ive been rocking biohazard in ghe shop lately.

Facebook post from the wife:

I think there is something wrong with my Amazon cart...random car parts (for big and little cars) keep popping up in my cart.

Oh, and anyone foolish enough to think that the Facebook post was a cute giggly note from my adoring wife doesn't know the full story. In reality, that was like walking through the bush and seeing the head of a Black Mamba rise above the grass. Akin to the mad stomping sounds of a moose in Canada during mating season. Like hearing a telltall rattle as you walk through the mountains. As if a Grizzly just hopped up on its hind legs. We're not playing around, it's time to take cover!

I know Ive mentioned it before, but I cant get over how awesome it is to have watched this thread go from

Tuna55 said: I think Im gonna sell this old truck because its rusty and Im not really sure I have the welding or fab skills to tackle it, plus the suspension is weird and its confusing to me...

to

Tuna55 said: So, I decided that I needed to revise the suspension so that the upper shock mount put the shocks in a position that also avoided the 96 Suburban swaybar I decided to graft into the rear end design, so heres how I did it...

I mean, thats pretty friggin awesome

In reply to 4cylndrfury:

Thanks! It's neat that everyone is seeing that, I only hope it's not incompetence disguised with ignorance!

After Tunawife made tuna salad with yours truly for a few hours, I got to stare at the rear end (of the truck) for a while. I eventually made the new damper mounts for the passenger side out of cardboard. A good step.

The drivers side is more difficult. Since the frame bends inward as it travels rearward, the newly splayed drivers side upper damper mount is about 4" closer to the centerline than the passenger side. What this means is that it smacks straight into my new swaybar. I would need to relocate the upper mount upward thusly.

But I don't like that very much.

Alternatively, the frame width is about the same distance as the bend. What this means is that I could potentially mount the damper on the outside of the frame on the drivers side as shown below.

I can't find any good shots of what the Suburban did, but I think the damper mounts were significantly more inboard off of bracket mounted to the top frame rail.

Yes, it's after midnight. Yes I just went downstairs in my PJs to look at the truck some more. My proposed idea of running just the drivers side damper outside the frame rail would work, and would place the two dampers about equidistant from the centerline, but the brackets would be different side-side. I am not sure I care, as they would both work the same. I would likely weld a thick section to the frame rail and drill through both sections, perhaps even adding a boss, to mount the damper. Not that the stock mount is that strong, but I don't want it failing.

This could work and work well.

Sounds like a great plan. The only downside as I see it is that in a significant hit, the mount could fail, whereas if its inboard, you may still be able to limp away. Simple solution: don't get in accidents. Bam, done.

I somehow missed the whole "buying Tuna springs" thing until this morning. I thew a couple of bucks at it anyway. Hope it's not too late to help. That's what I get for just looking at the pictures.

Thanks Mazda!

An additional comment about last night and my PJs. I cannot relocate the drivers side damper outside the frame rail as there is not lateral clearance between the frame and the spring.

I am not 100% sure how strong my new frame rail mounting point has to be. I am going back and forth between welding an extra layer or two to the frame rail and drilling it out, or concocting some sort of sleeve which gets welded to a web attached to the inner portion of the frame, effectively boxing that section. GM just threw the front damper in the frame rail in a hole, though, thusly

But that design is known as a weak point. Of course, adding an extra frame-rail-width layer increases the resistance to forces due to the moment caused by the dampers being in single shear by double, so that's pretty good. A tack weld on the inside of the rail for the mount would probably seal the deal without getting too extravagant. I'll play with it when my mounts come in.

Nope nope nope, I have another idea. Colleague Jim (who I have often derided for wanting to tighten flat head screws such that the flats are all aligned rather than how tight they were) and I spoke for a bit. I called him over as an expert witness on symmetry. He agreed that one mounting arrangement on one side and another on the other side would look weird.

The conclusion we came to is that it may be possible to cut down the damper mounting bracket to recess it further towards the frame rail, thus missing the swaybar mount laterally. I'll just slice off a couple of inches and redrill the holes based on those in the frame and be done.

Yeah?