Shouldnt parallel leaves be parallel??

looking at a factory 28 essex frame the rear leave mounts and shackels are something like 6" closer in the front than rear wont that make it handel funny or bind??

 

my 32 chevy is the same way

 

lots of methods were tried by early manufacturers to get an edge over the other guy somehow. considering the rear is a solid axle as long as the frame is straight i'd not worry over it.

 

I'm no expert, but given the name... yes.

That does seem very weird.

 

It is for proper handling. Most cars have the front of the springs mounted closer together than the rears. This makes it feel a little tighter.

Not sure about six inches closer though, wow!

 

....not unusual at all, especially on the front of cars/trucks.

 

May not have been that much but it was quite a bit

 

three inches per side? does'nt sound bad. measured from the driveshaft, are they the same symetrical ? if so, I'd say thats just the way they are

 

I know it's stock, but it just seems to me that would cause weird handeling

 

Really depends on which way you look at the springs..

 

Pretty sure your step-down Hudsons are the same way in the back, the front of the leaf is wider than at the rear.

 

almost all new trucks have the rear leafs closer in the front than at the rear....

 

Challengers and Cudas had the same in the rear. Was supposed to improve handling for the AAR series.

 

The automobile engineers figured out long ago that a hell of a lot of people just can't drive for shit. Most all leaf spring cars are set up this way for that reason. This causes a slight understeer during hard cornering, and prevents people from getting a car sideways, then over correcting themselves into a crash.

 

Elequintly put and Sooo true!!

 

All "parallel leaf" cars I've owned including everything from a '74 Datsun pickup, to my Ranchero, Blazer, Suburban, and a couple of '60's Mustangs were the same way-as in non-parallel...

 

learn something new every day.

 

As odd looking as it is, your Essex frame is just the way it should be. You won't have any problems with it.

 

Posies Super Slide In-d- Dirt springs (for 35-40 Fords) mount on the diagonal with the front spring perches inside the frame rails, in order to bring the rear of the car l-o-w-e-r. Works bitchin'.

 

I'm not sure angling the springs in plan will do that: I suspect that it's more about packaging. However, a lot of cars with a live axle on semi-elliptics do have the rear spring eyes considerably higher than the front, and that does impart roll understeer. If I remember correctly, Ford's Pinto and contemporary MkIII Cortina represented extreme examples of that thinking.

 

I wondered about that too. I'm doing a late leaf spring swap on my '49 GMC P/U.

I thought about pushing the forward hangers outward to make them truly parallel, but I'm no engineer, and I figure if it worked for pulling stumps out of the ground back in the day, it should definitely work for doing some burnouts today

 

Here's a great leaf spring tech article that may be of help; http://www.afcoracing.com/tech_pages/leaf.shtml

 

The Essex frame that you mention has the most exaggerated angle on the rear "parallel leaf" springs of any I have ever seen. It freaked me out when I first looked at my Essex chassis. Someone on the HAMB mentioned not too long ago that these Essex chasses were lusted after by some early hot rod racers (in the '30s or '40's) because of their excellent handling characteristics. I understand that they are kinda hard to come by, and that someone who was recently restoring a famous early hot rod racer couldn't find an Essex frame to replace the cobbled up one under the famous car.

 

I believe the term paralell spring means (to the frame rail). the pitch from front to rear on mounting will act as an anti sway measure.

 

Another terminoligy for the springs of which you talk is
Double Longitudinal!
They do not have to be parallel.

 

3/4 ton GM chassis has springs that appear parallel in the rear,front is the same as 1/2 ton. Modern rear leaf springs (SUV's and PU trucks) have the front of the spring about 3-5 inches lower than the rear.I believe this is to induce understeer .It's also my understanding that early sold axle cars with the engine mostly behind the front axle tend to oversteer.,so there probably were designs to give some front end push in hard turns.
Don't bad mouth understeer too much,especially if you got over your head in a turn with 50's PU truck and had the ass end snap around without warning.And steering too slow to catch it.

 

This whole thread makes me shake my head in disbelief! One constant trait found in posts on the HAMB is the great pride taken in totally disregarding proven engineering principles and laws of physics. "by Gawd, I've had my spherical ramisfrats that way for ten years and it has worked just fine!"

Glad to see some attention being paid to details! Carry on.....


Ray

 

The axle mounted in the dead center of the spring would lead to wicked wheel hop. Mopar super stock guys did a ton of research on this set-up back in the day. They learned leaf springs were pretty good, and clamping the leafs in front of the axle helped tracion. Herb Adams learned if you put one shock in the front of the axle and one behind, you dampen the harmonics even better. That's why Firebirds have one shock in front and one in behind. Leafs are a decent system, that's why cars have been running them for around a century.

 

It's easier than saying something like "isoceles trapezoidal" leaf springs, eh?

See... it's even harder to spell! Thanx Lobucrod, Gary

 

It's easier than saying 'isosceles trapezoidal' rear springs.