Hi guys, I'm building a 40 Tudor sedan and want to go to parallel leaf spring rear suspension. I have a Mopar a-body rear end with a perch to perch width of 43". What springs would you guys suggest I use? The a-body springs seem too long and the S10 springs I have seem too "tall". Any advice appreciated, thanks.
I used the parallel rear spring kit from Chassis Engineering bought thru Heidts.under my 40 coupe. They ride great. Little pricey but a bolt in.
I've done a few, and also have used Chassis Engineering, and also Weedetr. Rear Suspension - Suspension (weedetrstreetrod.com)
The Chassis Engineering kits are nice, but sit too tall. Need lowering blocks. 40 ragtop sells a kit and tells you what springs to buy (think they're Dodge truck springs). His bracketry goes up inside the chassis instead of under. He does nice work, and his stuff is reasonably priced. @40ragtopdown is the guy to talk to.
Back in '58 I put a '50 Merc rear end and springs in my '40. If I remember right, the width was fine and didn't even have to move the spring perches. Right wheel bolt pattern too.
The design with the spring fronts inside the chassis, I believe, are from Dale at Weedetr Street Rods. I had a really nice conversation with him at the 41st Forty Ford birthday party this September. He is a very knowledgeable man, with good sense. I would direct you to him, as that is where I am headed in the future.
Anyone with a plasma table can mimic someone's design, but I doubt they would have the knowledge to share and assist as the original designer.
A lot of Chrysler springs are set up with a longer rear length(past the center pin). If you have a spring shop nearby, you can have them re-roll the rear eye to get the length you want.
Stock springs from 65 to 71 dodge truck front work with the CE brackets. Eaton makes an awesome spring replacement kit for the CE, way better. Also, I’m currently running a CE kit in my sedan, and the Weedetr kit in my convertible. Both are excellent quality.
All good info above. I have done 2 40s with the kits from Chassis Eng. The springs have plastic sliders between the leaves which gives a nice ride. I also recommend the rear stabilizer bar from them.
I didn't build a lot of reproduction 35-40 customer chassis but probably did 30+ with parallel CE kits and never had a customer complaint about ride height or ride. Weedeater also has a nice kit.
What about "Posies" rear set up? I've used two of them and they are great. No lowering blocks needed. Two different ride height options with the kit.
Here's a couple pictures of Posies stuff under a '40 Tudor. It sat nice out of the box. The CE kits in my '47 and '35 both required blocks to sit right. Also, had to move the axle on the mounts to center the wheel. There's tech on here about using Chev AD truck front springs and hangers that looks OK too. https://www.jalopyjournal.com/forum/threads/low-buck-rear-springs-for-35-40-fords.557363/
I agree with the blocks on a CE kit, I used 2 inch blocks on my 40. I used an adjustable block from Speedway to get the wheelbase right. I never tried the Posie kit but it looks easy to install.
Just as a point of information, the drum to drum surface wheel mounting measurement on a stock 40 Ford rear is 59 1/2 in.
I got my kit from CE about 27 years ago.......came with Dodge truck springs...at least that's what CE told me.
Not only is Weedeter’s kit well made, you can discuss all areas of your build with Dale, the owner. Very knowledgeable and super nice guy.
hello........ IF you plan on using a 8 or 9 inch axle with 2 3/4'' tubes instead of a 3'' tube with rear parrallel leaves search dana 44 spring perch note that when fitted to a jeep they sit on top of the axle. notice that on some of them the distance from the leaf pack to the axles circle is greater than others - in effect lifting the suspension -so when you fit them to the bottom of your 8 or 9, it negates the need for a lowering block. its only about 1/2 -5/8th inch also they are hard to find anyway @ 2 3/4 some 8'' have the big locating hole for rubber isolators, when using the (thicker) spring perch / saddle, you can run a stock spring/shock mount too !! I think the main leaf of them eye to eye is four feet - 48 inches 1220mm the pin is in the middle the width is 2.5''
Most manufacturers do this. The total length is part of the stiffness equation. But locating the spring perch closer to the fixed hanger will control axle torque reaction and thrust. I have seen the results of turning the springs around to lengthen the wheelbase resulting in uncontrollable wheel hop. Racer's have known this for years, so a common mod was to add an extra 1/2 leaf as a traction aid [this doesn't stiffen the spring rate] Another Chrysler trick [and most manufacturers] was to mount the rear spring eyes a lot higher. This results in the front eye to spring perch being horizontal. This ^^^ is needed to control the wheelbase lengthening under compression [resulting in roll oversteer] Crawl under any factory leaf spring set-up and you will notice this [you can't unsee it once you know] It is also why single axle trailers are prone to swaying [and using trailer springs is not recommended for parallel leafs on a car]
You cant beat the ones that 40 ragtop down,i have used a set on a 46 2 door and a set on a 39 2 door. The price is better than other sets.
Almost three months since I ordered my Posies kit for my 36, I guess that’s the world we live in now?? So much for the winter project.
I just recieved the spring kit from Speedway. Ordered Tues. at 10 AM and got them Thurs at noon. Looks pretty simple to instal.
who has bought all the d100 front 1'' OD by 1/2'' ID - 2.5'' wide stock style bushings from rock auto? ggggrrrrrrr
I used rear springs and hangers/shackles from an '80 Isuzu pickup with the '74 Camaro 10 bolt rear in the '38 Ford pickup, basically the same frame as your '40. Didn't have to move the spring pads on the Camaro rear.
I used Chassie Engineerings kit, but I think the car got far to high. I`ve put 3 inch lowering blocks but that´s not enough so I concider taking off some blades and putting air bags between spring and frame
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