Leaf Spring install?

[Hedgehog]

Okay, just did a google search on "Automotive Leaf Spring Design" and skipped all the reading and went to "Images". It took some looking and even some reading. First off the clips are properly called "rebound clips". There are also many diagrams showing how a leaf spring is loaded during acceleration and the pretty much agree with what I have been saying. Looking further I see that 100% of the images showing a rear spring application showed the double rebound clip arrangement in front of the differential.

 

[Lumpy Grits]

KWEL-

LG

 

[caveman]

I have thought this out! Obviously folks don't agree with me on this. So, I want to put the burden on you, show me the error in my thinking. Remember that I just got don't looking at over a dozen sets of springs with the double clamps being about equally one way or the other, also to narrow down what someone is going to say, all of them were rear springs.

The error in your thinking is the direction of rotation of the axle. If the tires are trying to rotate forward, The axle will try to rotate backwards.

 

[Hedgehog]

Sorry but I disagree. According to 100% of the force diagrams related to automotive leaf spring design the axle will attempt to rotate forward or the front of the differential propeller shaft or universal joint attempts to dive down. Effectively opening up the spring stack in the front and tightening it in the rear.

 

[Kane]

Think of it this way. The pinion gear is pushing down in the ring gear in order to drive the vehicle forward. The ring gears will resist turning do to several factors, (the weight of the vehicle, the leverage of the tires IE Size, gravity). When the pinion gear forces the ring gear to rotate, the pinion will effectively move UP while the forward side of the ring gear moves DOWN. If the pinion gear is pushing down on the ring gear then the entire pinion assembly will move up. Since it is a rear end the pinion is facing forward and moving up mean rotating backwards. Like doing a push-up. You are pushing down on the floor which is moving you up.

 

[Hedgehog]

That would be ignoring the force being applied to the wheels/pavement.

Research says the two rebound clips go in the front (on the rear axle) and that's the way it's going to be on my jeep.

 

[Kane]

Leaf spring traction bars that are install on the old school muscle cars have a snubber at the end of the bar that hits the spring when the vehicle launches from a stop. The traction bar rotates up with the differential. The wheels with the force being applied to the pavement is driving forward and the axle housing is trying to rotate just the opposite.

 

[Hedgehog]

Research says the two rebound clips go in the front (on the rear axle) and that's the way it's going to be on my jeep.

 

[Kane]

https://www.youtube.com/watch?v=hiTRH1N_duo

Watch this video of the axle. It is little extreme with the lift block but the end result is the same.

I am not trying to defer you either way on the clips. I am just trying to help give an understanding of the axle rotation.

Maybe the two clips in the front are from the axle rotating forward under hard braking which exerts a much greater initial force than acceleration.

this is a good article on leaf springs.
Suspension Specialists, Technical Bulletin Number 4

 

[Hedgehog]

Well without question I have to admit that I was wrong ... once again in a long line of being wrong lately! There is a part of me that stubbornly wants to stick to my wrong headed idea, but in the end that serves no purpose. More than likely the diagrams I was looking at were addressing braking forces. None-the-less, they still show, for what ever reason the two rebound clips being in the front. And by golly since the axle is now set up that way I'm going to leave it that way.

Here's an attempt at a minor, yet dignified apology.

This is one very small part of a much bigger set of projects. (Regearing, installing an E-locker, new 21 gallon fuel tank, removing some excess steel placed by a PO, building a bumper w/swing out tire, fuel can, high lift jack carrier) I admit to being frustrated and WAY behind my goal completion date. I made my rear bumper using a couple modified stock trailer hitch parts that go from the frame to the bottom of the bumper. All seemed to go well except it was frustrating because the new gas tank got in the way making starting the nuts very fiddly and frustrating. When done I said, "I'll never ever do that again!" But when lifting the rear axle in place I find that the rear shackle bolts won't go in due to the darned modified stock parts. ERRRRRrrrrrrrrrrrr! The parts need to be removed and modified AGAIN. EEErrrrrrrrrrr! I've been dwelling on it for days. This is a process I have to go through until acceptance takes place and I can move forward with removing the part. A small piece that acceptance was realizing that the BOLTS can go in from the tank side making it easy to put the nuts on, it won't look as good, but will work just the same, except for the hit on my pride.

 

[Lumpy Grits]

https://www.youtube.com/watch?v=hiTRH1N_duo

Watch this video of the axle. It is little extreme with the lift block but the end result is the same.

I am not trying to defer you either way on the clips. I am just trying to help give an understanding of the axle rotation.

Maybe the two clips in the front are from the axle rotating forward under hard braking which exerts a much greater initial force than acceleration.

this is a good article on leaf springs.
Suspension Specialists, Technical Bulletin Number 4

After see'n those-There's no question how I would install mine
Those both, should be a 'stickies'--
LG

 

[Kane]

I am wrong all the time. Well everytime I have an argument with my wife. Just ask her. Haha.

 

[Lumpy Grits]

I could write a book on all of my 'wrongs'------

LG

 

[Hedgehog]

Feeling a little better today. Went home last night and after a little measuring realized a little grinding would get the job done on the shackle bolts without having to remove any parts. 1/2 hour later and I was hanging the springs in the shackles. I am beginning to worry about the differential clearing the new gas tank though.

 

[Lumpy Grits]

Just grease up the diff cover.
LG

 

[Hedgehog]

I'm itching to get the tires on with the CJ on the ground so I can jump up and down on it to see if the cover clears. Then take it out in the desert and bounce the jeep some. It is probably all right, but it did surprise me to see the potential for interference.

 

[Lumpy Grits]

Get to it-
LG

 

[Hedgehog]

The Jeep is up, it's running, no gear noise, the tab is bent out of the way, the gas gauge hasn't read over 1/3 full even with a full tank. The 3.31 gears are exactly what I was looking for. With the 3.73's I was always reaching for another gear and the CJ drove like it had a 2 speed Transmission . First to get things moving and third to drive on, second always seemed like a waste of time. Off road poking around on trails the jeep was perfectly happy in 3rd gear. While it doesn't seem crazy, on the interstate the engine turned 2,825 rpm @ 65 mph (measured on GPS), now with the 3.31's if loafs along at 2,400 rpm. A 400 rpm reduction doesn't seem like much, but by the seat of the pants it's a very different machine. Now to put some miles on it to see what kind of MPG difference there is. I'm not looking for a huge increase in mileage right now the CJ is right at 11 mpg, if I could get to 15 I'd be happy.

 

[Lumpy Grits]

OFS--
Best of news!
Put some pictures up. Like to see the gas tank vs. diff cover deal.
LG

 

[Hedgehog]

Well sorta - Now I need to wire the darned thing up. Shouldn't be big deal. I just hate wiring and I'm not quite sure of the routing yet. I'd like to have the switch up on the stick with the hand throttle. Do you see any reason that would be a bad idea?