why reverse the shackles? please discuss.

[JoeDaddy]

I was all set to yank the donor D60 and start the shackle reversal process but then was dumbstruck by the inherent flaw in it. The ford design is acurate.

So somebody please convince me theres a good reason to swap ends.

 

[JoeDaddy]

If you look at any off road or pulling (live) supension the hard end are toward the center. Every mud racer I've built has been the same, even using link bars to square vertical travel. If the hinge is rearward on the front axle its pusshing at the front 95% of the horizontal line, the rear axle at about 33%. For weight this is acurate given a 66%/33% front to rear split but for 4wd pullin racing or just torsional movement isn't having the force centered more efficiant?

What am I missing?

 

[Hotrodtractor]

You sir are wrong. Its that easy.

Putting the shackle towards the rear of the general direction of travel improves the ride quality as you hit bumps. When you hit a bump the axle wants to move up and rearward - with the shackle in the front the axle has to move forward when the suspension compresses making the ride much worse.

Any good off road suspension or pulling truck with a leaf spring front axle will have the shackles in the rear of the front leaf. In off road (short of rock crawling - can't say there) the shackle needs to be to the back for ride quality - in sled pulling the shackle needs to be to the back so as the front suspension droops the natural tendency for the axle is to also move forward helping weight transfer.

Etc.

 

[Zmann]

I don't know what you asking specifically because I am not familiar with older fords .. however on my old jeep everyone was taking the front mounted shackle and moving it to the rear in favor of the hard mount front

because when hitting a bump the front shackle pushes the axle into the obstacle as the arch of the spring compresses and thus making impact harsher or accelerated

does this sound like what your situation may be ?

 

[Zmann]

ok Hotrodtractor and I are on the same page .. I just type slower LOL

 

[Hotrodtractor]

ok Hotrodtractor and I are on the same page .. I just type slower LOL

BOOM! I'm faster where it counts and slower when needed!

Joe - he's just slow! :biggun:

 

[Zmann]

No comment


LOL

 

[JoeDaddy]

So it's bump related, my springs are flat, when they hit a bump the front axle will come reward.

Is ride the only reason?







And quit calling me sir, fag! :biggun:

 

[Zmann]

good point

and yes ride is the only reason I can think of?

most springs are arched so the flat spring may not have any benefit ?

never really thought about it that way

 

[Hotrodtractor]

So it's bump related, my springs are flat, when they hit a bump the front axle will come reward.

Is ride the only reason?







And quit calling me sir, fag! :biggun:

The spring is flat but the imaginary line drawn from the axle center line to the spring pivot point is not - you axle moves forward when you hit a bump.

 

[Zmann]

true I had to draw that out to make sense of it

 

[Charles]

All my buddies with YJ's used to constantly invert their shackles by ramming them into rocks and ledges when we were offroading. Talk about pissing away a good half-hour trying to get a shackle to flip back out.

For a vehicle exerting a lot of force on the frame via the front axle, I'm not sure that having the hanger in the rear, placing the spring in tension wouldn't actually be more stable than having the hanger in the front with the axle trying to buckle the springs.

Although with the hanger in the front I suspect the downforce would be greater as the axle would generally try to lift the front of the truck as it pushed forward, whereas with the hanger in the rear it would tend to pull the truck down.

Lastly, my superduty is a raging pile of fail in terms of front axle control in 4x4 in a hard pull, whereas my OBS is straight as an arrow.

But one has 4 times the hp as the other, and a standard steering box vs an orbital valve and cylinder.