Spindels?

[B.R.E.Demon]

Are the spindles on our cars forged or cast? I'm asking because my Pro Stock build will need custom lower ball joints to achieve the correct steering geometry. I'm considering removing the cast-in arm on the ball joint and welding a properly spaced steering arm onto the spindle (similar to the Rod Shop car) to reduce bump steer. This car is for track use only—no street driving.

 

[niceolddart]

I could be wrong but, I'm pretty sure they are ALL forgings. I don't think castings would hold up to the stresses on them. Someone here will know for sure.

 

[abdywgn]

would you be able to identify them like crankshafts? thin casting line or wide forging line?

 

[cudamark]

All the spindles I've dealt with were forged.

 

[MV8]

It looks like using a pan with a mid/front sump would allow a rear steer rack after swapping the knuckles around. Then the steering arms could be heated and brought down for less tie rod spacer, less anti-ackermann by placing the rack closer to the spindle, and much quicker steering with near, normal length steering arms

 

[72bluNblu]

Are the spindles on our cars forged or cast? I'm asking because my Pro Stock build will need custom lower ball joints to achieve the correct steering geometry. I'm considering removing the cast-in arm on the ball joint and welding a properly spaced steering arm onto the spindle (similar to the Rod Shop car) to reduce bump steer. This car is for track use only—no street driving.



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The knuckles are forged. Why do you want to weld the steering arm to the knuckle? You can bolt any manner of steering arm to the knuckle and doing that will be a stronger arrangement than trying weld to the knuckle. At least that way the steering arm is your only concern.

It looks like using a pan with a mid/front sump would allow a rear steer rack after swapping the knuckles around. Then the steering arms could be heated and brought down for less tie rod spacer, less anti-ackermann by placing the rack closer to the spindle, and much quicker steering with near, normal length steering arms

Swapping Mopar knuckles from side to side accomplishes nothing other than moving the brake calipers, it’s done all the time for that purpose and it doesn’t change the geometry at all. Flipping the steering arms is all that’s necessary, but as you’ve already pointed out unless you alter the geometry of them significantly the Ackerman is lousy. Less of a concern for a drag race only ride, but still a concern.

 

[B.R.E.Demon]

The knuckles are forged. Why do you want to weld the steering arm to the knuckle? You can bolt any manner of steering arm to the knuckle and doing that will be a stronger arrangement than trying weld to the knuckle. At least that way the steering arm is your only concern.



Swapping Mopar knuckles from side to side accomplishes nothing other than moving the brake calipers, it’s done all the time for that purpose and it doesn’t change the geometry at all. Flipping the steering arms is all that’s necessary, but as you’ve already pointed out unless you alter the geometry of them significantly the Ackerman is lousy. Less of a concern for a drag race only ride, but still a concern.

The reason for welding is that there are no arms with a 10" reach that can keep the rack aligned in the current plane without causing excessive binding due to the angle. Additionally, I want to avoid stacking issues with the Strange brake brackets. Running a ball joint on its own will reduce the weight of the assembly by trimming it down, and this setup will also offer better serviceability during racing. I'm also using heim joints instead of tie rod ends, so a partially fabricated spindle is an advantage.

 

[B.R.E.Demon]

This is what I developed to start with I plan to move the mount for the heim joint back to the first gusset once tacked I'm going to send them to the chassis shop for final welding. I spent some time talking with some old chassis guys yesterday an they said this would have been done in the era.

 

[72bluNblu]

No I get using a fabricated steering arm and removing the ball joint from the steering arm.

But I still do not see the reason to weld that to the knuckle. Obviously you’re going to have to fabricate the steering arm regardless. But welding that to the spindle will not have a strength advantage vs bolting it to the spindle. And actually dropping the box section for what’s basically just angle is going to be a strength issue itself with that long of a steering arm, the connection to the spindle will need to be beefy if you want it to live.

And why does using rod ends require a fabricated spindle? It would work exactly the same way with the rod end whether it’s bolted on or welded.

That’s also a ton of work to use a 9” spindle. I would think using a spindle with larger bearings would be advantageous with the high speeds involved.

 

[B.R.E.Demon]

No I get using a fabricated steering arm and removing the ball joint from the steering arm.

But I still do not see the reason to weld that to the knuckle. Obviously you’re going to have to fabricate the steering arm regardless. But welding that to the spindle will not have a strength advantage vs bolting it to the spindle. And actually dropping the box section for what’s basically just angle is going to be a strength issue itself with that long of a steering arm, the connection to the spindle will need to be beefy if you want it to live.

And why does using rod ends require a fabricated spindle? It would work exactly the same way with the rod end whether it’s bolted on or welded.

That’s also a ton of work to use a 9” spindle. I would think using a spindle with larger bearings would be advantageous with the high speeds involved.

I'm planning to shorten the arm a bit more, bringing the total length to 8 inches. With all the boxing in, I don’t foresee any potential for failure. I’ve also explored the idea of creating my own custom lower ball joint mount from scratch, designed to accept a properly tapered, threaded ball joint. One thing I've learned about Mopar is that while the design is great, many choices were made to reduce original production costs and make parts applicable across multiple platforms. For this reason, I prefer not to introduce heat to the ball joint casting by welding on it, as it seems to be cheaply made. The final design will be fully boxed in, similar to the one in the picture, with small sections welded to connect the webbing, making the arm a single piece.

The advantage of using heims in a fabricated design is that if you run a smooth OD bolt into a taper, you only have a small contact patch, which puts all the clamping and transitional force on the bolt—a potential point of failure. vs the continual contact patch in the fabricated arm.

As for the 9-inch spindle, I switched from the '73 and later disc brakes years ago in favor of these spindles. They're lighter and can be further milled to reduce weight. Aftermarket brake kits for drum spindles are also lighter. Bearings aren’t a concern, as we use the same series of ceramic bearings found in top fuel and funny cars, which are even smaller than ours.

 

[B.R.E.Demon]

It looks like using a pan with a mid/front sump would allow a rear steer rack after swapping the knuckles around. Then the steering arms could be heated and brought down for less tie rod spacer, less anti-ackermann by placing the rack closer to the spindle, and much quicker steering with near, normal length steering arms

The design of the current pan with the gen 2 hemi I will never be able to run a rearward rack. Plus the engines moved back 5% in the chassis.

 

[72bluNblu]

I'm planning to shorten the arm a bit more, bringing the total length to 8 inches. With all the boxing in, I don’t foresee any potential for failure. I’ve also explored the idea of creating my own custom lower ball joint mount from scratch, designed to accept a properly tapered, threaded ball joint. One thing I've learned about Mopar is that while the design is great, many choices were made to reduce original production costs and make parts applicable across multiple platforms. For this reason, I prefer not to introduce heat to the ball joint casting by welding on it, as it seems to be cheaply made. The final design will be fully boxed in, similar to the one in the picture, with small sections welded to connect the webbing, making the arm a single piece.

Have you looked at LCA's from the 73/74 B bodies? They mount the lower ball joint in the LCA directly and have a steering arm with no ball joint. The steering arm doesn't help you but the LCA might. Either way you'll still need something to hold the ball joint to the knuckle

But again, I'm not talking about welding on the stock steering arm. I'm suggesting that you should bolt your fabricated steering arm to the knuckles, because the way you're going to weld those arms to the knuckle will not be as strong. The rest of the construction isn't what I'm talking about either, the weakest point of this entire arm is right here at the red line, where you have designed in a hinge point with a large lever.

The advantage of using heims in a fabricated design is that if you run a smooth OD bolt into a taper, you only have a small contact patch, which puts all the clamping and transitional force on the bolt—a potential point of failure. vs the continual contact patch in the fabricated arm.

No, I get that. I'm saying you don't need to weld the fabricated steering arm to the spindle, because nothing changes for the rod end. You're still fabricating the steering arm, you just bolt it to the spindle because that will be a stronger arrangement

As for the 9-inch spindle, I switched from the '73 and later disc brakes years ago in favor of these spindles. They're lighter and can be further milled to reduce weight. Aftermarket brake kits for drum spindles are also lighter. Bearings aren’t a concern, as we use the same series of ceramic bearings found in top fuel and funny cars, which are even smaller than ours.

Hey if strength and bearing size aren't a concern for you then have at it. Personally I can't see racing one of these cars so competitively that a few ounces on the knuckles would be worth the loss of strength, but that's just my opinion. A knuckle failure at speed would be catastrophic

 

[B.R.E.Demon]

Have you looked at LCA's from the 73/74 B bodies? They mount the lower ball joint in the LCA directly and have a steering arm with no ball joint. The steering arm doesn't help you but the LCA might. Either way you'll still need something to hold the ball joint to the knuckle
View attachment 1716304130
But again, I'm not talking about welding on the stock steering arm. I'm suggesting that you should bolt your fabricated steering arm to the knuckles, because the way you're going to weld those arms to the knuckle will not be as strong. The rest of the construction isn't what I'm talking about either, the weakest point of this entire arm is right here at the red line, where you have designed in a hinge point with a large lever.

View attachment 1716304132


No, I get that. I'm saying you don't need to weld the fabricated steering arm to the spindle, because nothing changes for the rod end. You're still fabricating the steering arm, you just bolt it to the spindle because that will be a stronger arrangement



Hey if strength and bearing size aren't a concern for you then have at it. Personally I can't see racing one of these cars so competitively that a few ounces on the knuckles would be worth the loss of strength, but that's just my opinion. A knuckle failure at speed would be catastrophic

View attachment 1716304129

Yes I looked at those originally but I have the hdk lower arm kit so I can't change that. Just talked with an other buddy who dose chassis and we came up with this idea too. Instead of changing the arms go back to a factory ball joint but flipped side to side and then use these adapters like a dragster machine them to accept a clevis and run 5/8 heim joints with appropriate sewage tubes. That way there is no chance of binding or failure then just to ream out the tie rod hole and sleeve it

 

[B.R.E.Demon]

Have you looked at LCA's from the 73/74 B bodies? They mount the lower ball joint in the LCA directly and have a steering arm with no ball joint. The steering arm doesn't help you but the LCA might. Either way you'll still need something to hold the ball joint to the knuckle
View attachment 1716304130
But again, I'm not talking about welding on the stock steering arm. I'm suggesting that you should bolt your fabricated steering arm to the knuckles, because the way you're going to weld those arms to the knuckle will not be as strong. The rest of the construction isn't what I'm talking about either, the weakest point of this entire arm is right here at the red line, where you have designed in a hinge point with a large lever.

View attachment 1716304132


No, I get that. I'm saying you don't need to weld the fabricated steering arm to the spindle, because nothing changes for the rod end. You're still fabricating the steering arm, you just bolt it to the spindle because that will be a stronger arrangement



Hey if strength and bearing size aren't a concern for you then have at it. Personally I can't see racing one of these cars so competitively that a few ounces on the knuckles would be worth the loss of strength, but that's just my opinion. A knuckle failure at speed would be catastrophic

View attachment 1716304129

The other Idea too is run a c body lower ball joint as they are slightly longer, but I have to see if the bolt holes are the same spread....

 

[72bluNblu]

Yes I looked at those originally but I have the hdk lower arm kit so I can't change that. Just talked with an other buddy who dose chassis and we came up with this idea too. Instead of changing the arms go back to a factory ball joint but flipped side to side and then use these adapters like a dragster machine them to accept a clevis and run 5/8 heim joints with appropriate sewage tubes. That way there is no chance of binding or failure then just to ream out the tie rod hole and sleeve it View attachment 1716304142

But with those you'd be back the issue of the steering arms not being long enough, plus the ackerman issue right?

The other Idea too is run a c body lower ball joint as they are slightly longer, but I have to see if the bolt holes are the same spread....

They aren't. They're not even the same spread as the 73+ disk spindles, and the lower ball joints for the 9" drums are even narrower than those.

 

[B.R.E.Demon]

But with those you'd be back the issue of the steering arms not being long enough, plus the ackerman issue right?



They aren't. They're not even the same spread as the 73+ disk spindles, and the lower ball joints for the 9" drums are even narrower than those.

Yes that is true I already nix'd that idea and went back to a more traditional route, how much difference is the in bolt spacing on the spindle? as I have plug welded forgings before and re drilled them and if there is enough meat to do so that is an option. Otherwise I'm going to go to a buddy's place draw something up in cad and mill a one piece thread in unit. Its just weighing time and then having to send it out to be made at a short run cnc shop.

 

[jos51700]

They're all forged, 100%.

 

[JunkyJimmy]

Pinto spindles? Would need to slide the rack back, speedway has many options for them hub wise, many ball joints with longer, shorter, pins to get your height right.

 

[72bluNblu]

Pinto spindles? Would need to slide the rack back, speedway has many options for them hub wise, many ball joints with longer, shorter, pins to get your height right.

Definitely worth looking into, using a front steer spindle would likely improve a lot of the geometry as well. It's well demonstrated that using a Mopar spindle from this era doesn't work well with a front steer rack.

 

[B.R.E.Demon]

After cycling the suspension and going through the usual steps, I decided to use an offset heim joint to add about an inch of length. While this will still result in some bump steer, I’ll deal with that rather than CNCing a custom set of lower mounts. If the mock-up with these joints doesn’t work, I’ll adapt the welded-on arms, as I’ve seen on most pro-stock builds running Ford racks run custom steering arms. They either did something similar or cut off a C-body arm and welded it to the spindle. Heck, even Pintos had longer arms welded on.
pinto