leaf-link suspensions... learn me something

was doing a lil research for something i got in the back of my head and came across stuff about leaf-link suspensions in pro stock dodges in the 60's... i just cant wrap my head around how they work keeping the pinion angle constant and not have suspension bind being hooked up front and rear on the leafs... anyone care to shed some light on this for me? words are good, pics would be better. LOL

thanks

 

No expert Trav but the rear axle is in a "floater" as I understand it. Think of the springs as two arms of a 4-link. I think the AWB Dart in Hot Rod Deluxe a couple issues back showed it pretty well.

 

i'm gonna have to take a look at that one. i'm missin an issue or two of that one, and its prolly the one with the dart. lol

 

The centrally located pinion snubber is set up to bottom out quite early as well.

 

Hagr?

 

I believe those cars used "super stock" springs. The front of the spring pack may have extra springs that were clamped together. The rear of the spring was left loose. The front half of the spring acted as a solid link. There was a pinion snubber that contacted the floor pan. You could also add extra leaves to the passenger side leaf spring to adjust pre-load.

 

nah, something even more retarded...

 

lawnmower?

 

49cc powered foosball table...

 

I wrote a 10-page story on Leaf Link suspension fabrication two or three issues ago in Hot Rod Deluxe. It's in my '57 2dr wagon gasser.
Solid rods on top of the housing, just like the top bars of a four link.
The front half of the leaf spring, from the axle to the eye, is clamped solid with heavy duty shop-made clamps (3/8x1 inch cold-rolled bar stock; one on top and bottom of the spring pack, bolted together. One set of clamps at each point where a leaf ends). This makes the front half of the leaf spring act as a solid link, like the bottom link of a 4-link.
All the leaf spring clamps are removed from the back half of the leaf spring. This lets the spring actually spring, react to bumps in the road, etc.
Now, the key is the floating rear end housing mount. The stock spring perches are removed from the housing. A special bracket is fab'd that clamps to the leaf spring. The bracket hangs below the spring, and has a thru-bolt sleeve running side-to-side.
A pair of ears are welded to the axle tube: one ear on the inside of the spring, one on the outside of the spring. These ears have a bolt hole in them at the bottom--that hole lines up with the thru-bolt sleeve on the bottom bracket. A large bolt fastens the housing bracket to the leaf spring bracket, and acts as an axle or pivot point.
As the suspension goes up and down, the axle's pinion angle remains constant, but the suspension doesn't bind because the only place it rides on the springs is at that pivoting bolt.
On mine, the upper link has two settings on the housing, and three where it attaches to the frame rail. The front spring eye has two settings where it attaches to the chassis. There are three mounting holes on the housing's tabs where it bolts to the leaf spring bracket, and two holes on the bracket, for a total of five more adjustments.
Do the math, and it has a few dozen settings to triangulate the rear suspension and make the car hook.
plus, pinion angle is adjustable by lengthening or shortening the upper links. (Heim ends on the bars).
A pinion snubber is NOT needed, as the rear end housing doesn't "wrap" like it does on leaf springs alone.

Ya really gotta start reading Hot Rod Deluxe!

-Brad

 

Or you could get one of those Mopar performance "how to" books like I have here and read how and why they work and how to build it with factory pictures and measurements. Gene

 

I recall the Fireball 500 Baracuda using a leaflink set up Traves. Checked it out at the Mopar Nats in 86.
The set up under that car incorporated just the front halves of the leaf springs and used coil springs in conjuntion. Pretty much looked like a GM coil rearend set up but instead of trailiing arms used the half leafs. Im sure there was more involved but that was along time ago that I seen it.

 

Fiddy, if you need the floater part my pal randy has it down. The Bushmasters 55 just got the treatment! Yeah, Jesse is still alive..............

 

This is a great thread! Most don't know about leaf-links! Brad, that was a good story you did!
On the AWB Darts, we did not use leaf-link style suspensions, but factory MOPAR springs. The 003-004's on Steve's, and superstocks on mine.

Bob Mosher(wwwmoparsbymosher.com) has one of his old period drag cars that still has an original leaf-link set-up. Its sooo old school bitchin!. He asked me about the possibility of four-linking it. Tough decision, as its a period perfect car. I'm still tryin to convince him to leave it be.

 

Brad... Ocock??? sweet! i looked in the shop and found that issue. dont know why that article slipped my mind, maybe cause the solo speed shop/blair's chevy was in the same issue?

either way, i read over the article real well, and combined with your reply, i have a good handle on this suspension... million thanks

 

Glad to help.

-Brad

 

Anyone have a picture they can post? I'm too stupid to get my brain to visualize this.

 

Don't know if this is even close but I'm picturing a set up like the Cal-Tracs. Or am I way off with my visualization as well.

 

what he says

 

whats retarded about an HA/GR????
and why are you comin to help build mine??? you callin me retarded???

 

Here's some pics from the story.
They show the brackets that hang under the rear end housing and attach the housing to the leaf springs, the upper links (the bracket on top of the housing that the link attaches to has another mounting hole, just visible under the bolt), a shot of the housing on the leaf spring bracket to demonstrate how the housing rocks on the one mounting bolt/pivot, and the final shot shows the desired effect: with all adjustments, the goal is to triangulate the rear suspension so it lifts from the car's instant center, which is the same way a 4-link works. Only this way is much, much cheaper.

-Brad

 

well.... who says i'm gunna help build yurs?

as for weather you're retarded or not... ah, err... um! you DO own yur own short bus.

 

yeah....i really need to sell that thing!!!!
you wanna work on your motor dontcha? well, then your gonna have to help get my shit out the way!!!

 

IF... everything goes my way (yea, as IF) and if i can score the parts... i might be drivin the willys by sunday

 

hell ya bro! that would rock!!!!!!!!1

 

OK...

1) Thanks SO much for the pics. I have a much better understanding of what's going on (it was a hard day at the office with Accounting $ and spreadsheets!);
2) Does the upper link attach to the frame just like the upper mount of a four-link?
3) *stupid question alert!* If the bottom leaves are hard-bolted together (acting as a solid lower link) and there is an upper solid link, couldn't you just cut the rear portion of the leaf springs OFF, taking into consideration that you had a coilover or airbag to support the rear end?
4) If you leave the rear portion of the springs intact could you use this method in conjunction with some sort of adjustable suspension?

 

1) Glad to hear it
2) upper link does attach to the frame like a 4-link. You could probably build a cross member, but we welded big honkin nuts to a plate (3, spaced 1-inch apart) and welded the plate to the inside of the frame rail. for this next step, imagine a piece of box tubing. Now cut ONE side of the box tubing off, so it's essentially a C-channel. Now drill three holes in the right and left piece of the C-channel, leaving the other one undrilled. Now slide the link's Heim joint into the C-channel, and run a bolt through any of the three holes. The plate with the nuts welded to the frame is one side of that C-channel. We cut TWO sides off a piece of box tubing, then welded the tubing to the frame, and gusseted it. This is the forward mount for the upper link.
3)You probably good, but to what end? The beauty of a leaf link is that it's inexpensive. You've just added the cost of coil overs or air bags to the project.
4) The entire rear suspension IS adjustable. Front leaf spring has two positions, front of link has three positions (2x3=6). Rear of upper link has two positions to mount on housing ( 6x2=12). There are three holes in the housing mount tabs, and two holes in the pivot mount. With the way everything lines up, there are 5 different positions that pivot can go. (12x5=60). 60 different adjustment positions, plus you can dial in more or less pinion angle.

For a drag race application, it's great.

For air ride, you could probably do quarter-elliptical springs and do away with all the other adjustments, giving it one mounting point at the front leaf spring eye, one mounting point at the front of the upper link, one mounting point at the link on the housing, and one pivot point on the spring mount.

-Brad

 

I am thinking Mopar, Dick Landy, 1960's drag racing, I am sure I saw some article years ago and it had similar pic's.

 

At first I thought it may be set up as 2 half leaf springs mounted to the chassis with the eyes mounted to the axle- top of the axle tube and the bottom of the axle tube, so picture a leaf spring cut in half and mounted like ¼ elliptic just 2 of them per side. Would it work?

 

It probably works but dont mean it is desirable and the OEM dont use it any more.
I guess that speaks for itself.