So, realizing I don't understand all I know about buggy spring suspensions, I'm getting ready set up the axle (55 Chev) under my '34. The car is mocked up in the shop, I want to center the wheel in the character line of the wheel well. The crossmember is not in the frame, I've got a '40 that I intend to flatten. I have a set of Speedway shackle perches, 8" long, and a set of 6" long ones as well. I also have a mono-leaf '40 rear spring. Here's my question: The spring is 46" eye to eye unloaded. I've read to put shackles on the springs, then at 1 to 1.5" (which should it be?) for each side to total an additional 2-3" for the distance between the shackle centers on the axle. Is that with the shackles at 90 to the spring, or say a 45? This is a reverse eye spring, I would think I'll be able to clamp it to a piece of angle, shorter than the total length, to compress it to mount, but I'm (probably overthinking) unsure of how much it should be compressed at static load, and the eye to eye distance of the shackle mount on the rear end. I'm also planning un using a set of '36 front 'bones as lower radius rods, along with a center link (to replace the torque tube) that'll all pivot at the same point on the chassis, and I don't see why I couldn't use the '36 ball and rubber pivot mount as well. Any thoughts or advice on the dimensions I need to use? I tried the search function, and came up with lots of threads on using a 36-40 front spring.
On a 40 ford spring I weld perches 48" a fully flat cross will probably set the car too low with that combo I know for sure on a 32 it would be setting on the frame ....an those kickups are similiar .. i would guess with a mono reverse your going to want a 2-3" rise prob with a reverse eye mono The center pin from a curved rear spring on 34 rear doesn't change vs 40 spring with 35-48 perches if that makes sense... But it will hug the front of the wheel well ....to " center" it it's probably going to have to scoot back close to 1/2 approx ...give or take I would incorporate the spring mounts that are on the wishbone also.. Much cleaner look Btw the speedway one need to be trimmed back and are also welded crooked in the same direction , allow for that or cut tube off and weld back on straight Never mind on some of the above.. I see your using a 36 front bone... My feeling that is a little too short to run it unsplit...
Thanks for the info. I'm surprised nobody else chimed in, I can't be the first to scratch his head a bit over this one. I'm planning on a 3 link arrangement, making a torque arm to mimic the original torque tube, and the '36 bones are much longer than the 4 link, unequal length control arm I've done several times (mimicking GM's 60's-70's style with light coils). Looking at my front (now rear) wishbone, I think I can use the original ball and socket just like Ford did, and have the torque arm mount in line with that. Should work, yes?
The mono leaf does allow for adjustment of height depending whether the spacer block is above or below the spring. And yes, it's a reversed eye. I want the car low, have a 4" drop front, flattened and reversed eye spring for that, hopefully, that'll be enough...
Yes. I am building mine similarly, but with rear bones. Rear bones will incorporate spring hangars too. Then you can weld mounts on the axle where you need them.
My chassis flipped over https://www.instagram.com/p/1Y1GLcOh8t/ And a closer view https://www.instagram.com/p/3osGKVOh27/ lot's of inspiration in these threads; http://www.jalopyjournal.com/forum/threads/tech-week-hot-rod-suspension-simplified.677460/ http://www.jalopyjournal.com/forum/...erfect-1932-34-chassis-picture-thread.692288/ http://www.jalopyjournal.com/forum/threads/my-dads-34-roadster-frame-from-ionia-hot-rods.404390/
I just did '35/36 rear perches on a narrow 9" with a flatttened '40 cross member in a '32 frame with a stock 11 leaf Ford front spring that measured 37" center to center. I set the perches at 40" (1-1/2" per side) and with some pre-load I installed the shackles at almost 45 *. It's still in the frame jig so I don't know yet what real ride height will be but I think it will be fine. I will do a C-notch just because.
This is a 32 frame i did , but again kickup is similar so the rules mostly apply...,flat 40 cross and stock 40 spring , so that would be similiar to all the shims stacked on top of the spring , car needed extra leafs My thought on the 36 front bone is your ball socket will be in the middle of the drive shaft area Also I should point out my 48" measurement is base of stock stock perch width and stock spring never measured the spring... I know they offer a narrower than stock spring and you would narrow perch width accordingly from that number
Thanks guys, with all that info to help, I should be able to make it work even with my limited skill set!
Personally, long shackles will make the car sway a lot. I would use stock shackles from P&J as your set up will be low as described.
The shackles are stock, I'm talking about the brackets which mount them to the axle. Unless I'm mistaken, I need the 8" long ones for the spring behind the axle set up I'm doing.
The speedway ones are long about an inch or so you can use them as is , but it would shove your crossmember into your gas tank if using one... I like to trim them to stock ford so there is a " known" measurement I will go to the shop and get a measurement from c/l of housing to end of mount from a banjo for you
Right now the top of the axle tubes are 3" below the frame rails. I moved my axle back almost 3" so the flattened cross member is in the area where the rails start to drop. This car is a 28/29 rpu with a body lengthened 4" in the doors and rear quarters, hence the longer wheelbase. I agree it's gonna be a little dicey. If I have to make much change I will do so with another cross member as I only have it bolted in place. Hell, I've been wrong before and I try to plan for potential changes. It IS hard to calculate how to end up just right. I reread dozens of threads on this and related subject matter on the HAMB in the last few weeks and can only say that it is doubly hard to sort out who knows exactly what to do and who knows jack-shit. I appreciate the heads-up and If I'm off I will gladly admit it and offer up Plan B. Charlie
I've done the front spring thing twice.. bit me both times , I thought I did the math , pulled leafs cause it was stiff sat good for about a month... Everything settled I needed a 2" block
Here's a modified 40 rear crossmember and a 40 front spring. Great set up for a big rear tire car. The perches are custom and the perch Eye is even with the bottom of the axle tube. The perches are 42.5" center to center. 3.5" dip in crossmember and 2.5 inch arch in spring main leaf. Running centers less than 42.5 reduces preload and increases the spring rate making it stiffer- stiffer by the exact amount of missing preload
Thanks thirty-two. Nice work 31Vicky on that rear set up, I'll end up boxing the spindly looking Speedway brackets like you've done with those. I'm sticking with the 46" mono-leaf though, although I do have a '36 front spring, I've got room to get the 48" centers on the mounts. I'm planning on leaving a 2" drop on the '40 crossmember, not making it completely flat too...
What the Posies stuff doesn't tell is the length of their spring to the corresponding rear end perch C/L. That is the case pretty much with all the spring sellers. They will sell you a spring to meet your perches but don't show the perch distance you should have for a given spring. When I was setting mine up I made a 2" inch spacer and put the main leaf under it, put it in the cross member and it would not reach to a 42-1/2 perch. My spring is 37" C/L at rest so I searched more and found numbers like 2" - 2-1/2 and 2" - 3. from what you have in hand. It will be what it will be and I'll deal with it when I get the frame out of the jig in the next few weeks. I'm tack welding sufficient to hold it together and get it on the ground and stick a little weight on the back. The car is a no-fender rpu so it won't be extremely heavy.
Well, they do give a part # and the speced perch C/L for that Corresponding part #. These old ford Transverse style springs are mounted in tension, and I believe they are the only ones like that. So having the specs like most leaf springs do in catalogs isn't much help anyway- free arch and eye to eye
I'm setting up a 34 frame now with a 37 front spring in the original rear cross member, seems a good way to go using original Ford parts and some hot rod fabrication ! Good luck
Rule of thumb on the spring length is, perch center to center,minus 5 inches gives you the spring length. Or spring eyes plus 5"
Brian, I ask this question of anybody who is setting up a frame, do you ever forse installing a quickchange? If yes, need to think model a cross member, No, continue on your current path.
I have a '40 spring behind a '57 Chevy rear end mounted to a flat crossmember on my roadster. I took a little experimentation, wound up pulling a leaf and shortening some shackles to get it dialed in. It now handles great and is actually quite comfortable in terms of ride quality. I can measure perch distance for you this weekend if you want.
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