Technical Axle Question

[Tank6x2]

open to anybody who wants to share, is the reason the rear shock brackets are offset from front and rear sides of the axle due to torsional load or was this just a slight difference in patent design to allow the same design from Chevy Dodge Ford to be used with a minor alteration to design so it changes the patent??

 

[Blue Ox]

GM says it's to prevent axle hop.

Of course, that could just be what they tell the public instead of "We did it to get around patents."

 

[SquareRoot]

Yo

open to anybody who wants to share, is the reason the rear shock brackets are offset from front and rear sides of the axle due to torsional load or was this just a slight difference in patent design to allow the same design from Chevy Dodge Ford to be used with a minor alteration to design so it changes the patent??

Your first thought.

 

[Tank6x2]

Well got another posted line of thread “Storming Norman Tank” on here in under construction, but never really gave shock load and position much thought for it until I began preparing the four link brackets this week. Could use a panhard bar to offset the torsional load, but the question now is position it to front or rear of the pumpkin 90• to axle orientation to frame or offset it to 100/110• to frame direction and how much angle for position 90• from ride height position of the shock or will it need more of an angle...any thoughts on this?

 

[Blue Ox]

Multilink suspension is a totally different animal than leaf spring. You won't need to fore and aft the shocks to control the axle with links.

I'm not quite sure what you're describing about the panhard bar. Usually they're only for lateral location of the axle. Ideally shocks should be positioned as far outboard as you can get them and in line with the axle's arc of motion. Reality usually requires some compromises, however.

 

[dvdswan]

Ideally, shocks are just to dampen return from a load/unload condition to reduce bounce which would cause a control/traction issue.

As @Blue Ox stated link suspension is totally different from leaf springs. So the angle of the shock may add some stability assistance to the suspension, but I'm not an engineer. Won't go there as many times I have thought what idiot thought of making this like this and end up throwing a wrench. I'm sure there are advantages and disadvantages to all shock setups.

I have 3-link frt and rear on my play toy and the coilovers are near 90* over the axle and the track bar/panhard bar/lateral bar is just to keep the axle centered side to side. The ride and flexibility is 10x better than leaves. IMO.

 

[Tank6x2]

Radial Axis, this is true yet when you look at the axles movement is it not more a straight line that moves in a large circular motion?

Maybe 90• to ride height position...

But if I want them as far out as possible and directly over the axle, why is it GM that Angled them from lower centre outward ?

 

[shiftpro]

If the shocks were mounted 90* from the axle, they would protrude through the box or front fenders. When a shock is at an angle, the travel speed slows down. Want to make a stiff shock feel softer? Mount it an an angle.

 

[Blue Ox]

Because leaf springs twist and wind up under acceleration and deceleration torque. Multi links control that better so the shocks can be placed in a more ideal position to control the axle. You might want to invest in a book about suspension systems. What you're doing is basically a racecar suspension, but with an obscene amount of unsprung weight. It's going to give you a lot of trouble controlling that axle.

 

[75gmck25]

Staggered rear shocks were a common performance car option in the 60's and it was always advertised as limiting axle wind-up under acceleration. It was also common to relocate the spare tire to the right rear side of the trunk to provide more weight on that side of the car and push against the wind-up.

Bruce

 

[HotRodPC]

Ideally, shocks are just to dampen return from a load/unload condition to reduce bounce which would cause a control/traction issue.

As @Blue Ox stated link suspension is totally different from leaf springs. So the angle of the shock may add some stability assistance to the suspension, but I'm not an engineer. Won't go there as many times I have thought what idiot thought of making this like this and end up throwing a wrench. I'm sure there are advantages and disadvantages to all shock setups.

I have 3-link frt and rear on my play toy and the coilovers are near 90* over the axle and the track bar/panhard bar/lateral bar is just to keep the axle centered side to side. The ride and flexibility is 10x better than leaves. IMO.

While a shock does this too. Most aren't aware of the main purpose of a shock. Sure it has other purposes and does other things but it's #1 purpose and job is not what most will think. And for those who think, I'm carrying a heavy load, so I need heavier shocks as if the shocks support the weight and they DO NOT. Springs carry the weight, shocks do as you mentioned, dampen the return or bounce. But the main purpose of a shock is hold the tire to the ground. If you're ever seen tires that are cupped all the way around. That's due to bad shocks where the tire was allowed to dribble like a basketball as your driving down the freeway and beating the hell outta the tire. But true it is, shocks wear a few different hats and do different things and why it's not a bad idea to consider quality when buying shocks for reasons of safety, comfort, traction, tire longevity etc.

 

[Blue Ox]

That's what I meant about controlling the axle. It's all about getting maximum tire contact with the ground. That heavy 14 bolt with drums and dual wheels is an insane amount of unsprung weight to try to corral. He's going to have his work cut out for him.