Trust me I know. They're also course thread u bolts but when/if I flip them I'll be using the proper bolts, nuts and only the thick washers.
I would suggest two things to consider. !) 'shorten' the height of the axle/spring mounting pad...it's much deeper than it needs to be....or shorten the lowering block a an inch, same effect and easier...... 2) it looks like you lowering blocks are solid aluminum billets. Get a 'both ends threaded' shock mounting stud (Seems to me C-10 Pickups of the '60s had those as do other maker and models) and drill and tap the lowering block for the shock stud. Those mods will raise your scrub line accordingly. Also, the 'squared of U bolts I recommended will not use the old shock plate anyway. The U bolts will be mounted 'crosswise' to the present U bolts. One U bolt in front of axle, second U bolt behind axle......U bolt points up and goes under the spring past the lower block, past the axle to the 'muffler clamps' we discussed in an earlier post. 'voila, improved scrub line.
That's the main thing that got me thinking about a link suspension. I dont want to raise my rear end at all. I knew the u bolts would go side to side, but I figured I would still use the shock mount since the factory u bolts went side to side as opposed to front to back as well. Thinking about it, I actually need new shocks anyway, so I may just buy shorter ones and use axle mounted shock brackets, which is what I'll have to do if I 4-link it anyway.
As far as pulling that bottom leaf, would that have any affect on anything besides spring pack thickness?
Just use Lug Nuts put on backwards. It gives them the extra thread length and the taper isn't load bearing
I think I'll be replacing the u bolts soon. I just have to get my notches made and put in so the nuts don't jam into my frame. I'm going to the metal place today or tomorrow to buy the 3/16 to make them.
Get those springs re-set about 2" lower. That way you can remove 2" from the lowering blocks You can still used smaller lowering blocks to adjust the final ride height. A flatter arched leaf spring will control lateral movement better. Whereas your present set-up may require a panhard bar if there is minimal clearance between the tyre and the wheel arch. Re-arching the spring doesn't alter the stiffness at all. The spring load is linear to the weight upon in. So if you flattened the arch [unsprung] 2" the car will sit 2" lower if the weight is the same. Re-arching the springs is cheaper than adding links / panhard bars etc
Removing Leafs will do that!!!!! [Or if the springmaker is a dickhead and heats the springs red hot to lose tensile strength] The spring stiffness stays the same for the lifetime of the spring. BUT Over millions of oscillations they will slowly lose their set [or load height] The remedy in normal situations is to "Re-Arch" them to the desired ride height This is usually a Cold Process edit: here is a link on the HAMB where a mainleaf was reshaped with a bottle jack [ pictured post #5 ] to reverse eye it. The same process can be used to de/re-arch https://www.jalopyjournal.com/forum/threads/chassis-reversing-spring-eyes.90824/
I didn't realize that. I always thought the spring "strength" was dependant on the arch. I wonder what makes the aftermarket springs invert faster, crap metal maybe? What do you do about length when you de-arch the spring? The eye has maybe and inch between it and the shackle bracket. I would assume that making the pack flatter would also make it longer, wouldn't it?
The correct term is "Modulus of elasticity" [the tendency of an object to deform along an axis when opposing forces are applied along that axis] If you loaded 1-ton of extra weight in the rear is will deform a lot faster. [but you aren't doing that] Go back to the fact, your present springs are 65 years old at it's present setting . You are turning back the clock by re-setting them.
Alright, my local spring shop said they can do it for $45/spring pack. Do the spring packs not elongate much during the de-arching process? I would hate to have the shop do it only to find out that the rear spring eye rests against the shackle mount afterwards
A leaf spring would normally lengthen when it conpresses. So re-setting the spring 2" lower would be no worse than if the suspension absorbed a 2" bump. If you're going to notch the frame for axle clearance, while you're at it why don't you notch the frame a bit behind the rear shackle to allow for a bit more shackle swivel during extreme suspension travel.
The shackle hanger on these Chevys cant be notched. They're a C shaped bracket that the shackle goes up into.
Like this [I found on the 'net] Firstly because you're flattening the springs, it is only imitating the range of movement of stock springs [only the static and ride height is changed] Once a spring is compressed dead straight, it then continues to invert and shorten [before it rebounds back again] It is highly unlikely your spring will bind against these hangers under most driving conditions. BUT If you're capable of notching your frame, you are certainly capable of relocating these rearwards My best advice here is measure everything now, then try it and see . [I love the 2x4 installation tool in the photo]
I could definitely relocate the hangers but then that's going to move the wheel back however far and I'm not running skirts
If it did, you could re-drill the spring pads on the diff housing But it shouldn't alter the wheelbase at all due to design! Firstly most leaf springs have the centrebolt offset to the front [front 1/2 shorter than the rear 1/2] The shorter front half controls engine and brake torque while the longer rear half maintains a softer ride. Now , have a good look under your car at the angle of your leaf spring suspension. You will notice the rear spring eye is a lot higher than the front spring eye. [see photo for example] Manufacturers do this deliberately [except "cowshed engineers" building trailers] to reduce the wheelbase variation during suspension compression. It is preferable for the wheelbase to shorten instead of lengthening [Arcing forward]. Shortening induces "Roll Understeer" which is more desirable/stable during cornering or bumpy roads. So resetting the springs shouldn't alter the wheelbase [if any ,it should make it slightly shorter]
I re-read my comment and you're right, that makes no sense that moving the shackle mount would change the wheelbase, since the shackle is the pivot point. Is there a calculation to figure out how far the center pin will move in comparison to the eye to eye length growing? I have 1.5" hole spacing on my perches/bottom plates so I can move the axle forward that amount if necessary. As it sits my driveshaft is pulled out of the t5 about as far as it can go without causing any concern
Why not move the springs to the inside and up higher on the frame? Have to move the mounts and the axle perches, but the axle and ride height will be the same. You could shorten the lowering blocks and your scrub is taken care of
I thought about doing that as well. The only problem with that is the exhaust pipes go between the gas tank/spare tire well and the shackles. If I moved the Springs in and up they would be directly in the path of the exhaust.
I think if de arching the Springs works as well as everyone's saying it does and doesnt increase their likelihood of going bad, that's the way to go. Now if I can just figure out exactly how much the center pin on the Springs is going to move rearward
Read this: https://mobiloil.com/en/article/car...archive/how-to-restore-leaf-spring-suspension I've always re-set springs on my old race cars [Lotus Cortina, Capri, C3 Corvette rear] and never given it a 2nd thought. I have also used an extra 1/2 leaf on the top which requires a longer centrebolt and clamp at the front. [this helps control "axle tramping" and brake torque, without altering the suspension geometry] The extra 1/2 leaf on top lowers the car the thickness of the leaf. With your driveshaft yoke ! You can buy a yoke that is longer down the spline/shaft so that drive shafts don't need lengthening. Ford used these on FR500C race cars https://www.dennysdriveshaft.com/p1...310_slip_yoke_fits_all_gm_transmissions_.html
I'm still back and forth on a 4-link kit. Since mine is a daily driver, does bushing size matter? I notice the Gambino and Welder Series bushings are much smaller than the Suicide Doors bushings. Would the smaller size bushings work/last on the street? Keep in mind I wont be raising or lowering the rear
I also just came across this. I dont know if this would be strong enough since the frame sidewall is only 1/8" thick though. I was thinking maybe I could make brackets out of 1/4" that bolt to the original holes, go up inside the frame at 90° and then do something like this. Maybe even make a sort of step and bolt the original brackets in place..? I could gusset the L at the top but the frame would be in the way on the bottom L. Do you guys think welded quarter inch would be strong enough to support the whole shebang? I may be able to bend it out of a solid piece but I feel like it would be tough to make the brackets identical on both sides.
What's wrong with paying somebody $45 a side for the springs instead of re-engineering the whole rear end
I was under the car today trimming off the excess u-bolt threads and I noticed the springs are almost flat already. If I take them down enough to lose the block they'll be in a reverse arch.
Do you realise that leaf springs have the same rating regardless of the shape [which is why re-setting works so well for lowering without altering ride quality] A flat spring that inverts during compression has the same stiffness as a slightly arched spring that flattens under load. Leaf spring are progressive in compression but not in extension or "droop" [unless all the smaller leafs are tied to the mainleaf] NOW!!!! If you don't want to reset the springs, and want to stay with lowering blocks. Make the lowering blocks from steel and stitch weld them to the spring pad on the diff. This controls lateral loads better during cornering because the lowering block normally tries to roll-over with the spring. And make sure the centrebolt hole is a neat fit in the lowering block With 3" lowering blocks ,you should seriously consider a front 1/2 leaf that is clamped near the front spring eye and fits totally under the spring pad/lowering block A front 1/2 leaf goes on top of the spring and controls torque Try and keep it simple
So if I bend the spring 3" into a reverse arch, it'll still support the weight of the rear and essentially perform as it did when it still had a positive arch (except of course that it'll be shortening and pulling the shackle forward instead of lengthening and pushing it rearward on compression)?
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