Alignment Specs (tubular/strut rods)

[swinger74]

Hello,

I have a 74 dart with tubular upper and lowers along with adjustable strut rods. Is there a recommended alignment spec to give the shop? i have it decent enough to get to the shop but dont know if there is a preferred set of specs.

Thanks
Ryan

 

[RustyRatRod]

...

 

[72bluNblu]

Yup, the skosh chart is pretty much the way to go. With tubular uppers you can probably get more positive caster than what's shown in the chart. If you have power steering shooting for +5° caster would be good. If you have manual steering you might not want quite that much, depends on the use of the car and tires you're running. But say -.5° camber, +3 to +5° caster, and about 1/16" toe in should work well for most street applications.

How did you set the length on the adjustable strut rods? Hopefully you cycled the suspension through its range of travel to make sure nothing was binding. The alignment shop most likely won't want anything to do with adjusting those.

 

[famous bob]

Yup, the skosh chart is pretty much the way to go. With tubular uppers you can probably get more positive caster than what's shown in the chart. If you have power steering shooting for +5° caster would be good. If you have manual steering you might not want quite that much, depends on the use of the car and tires you're running. But say -.5° camber, +3 to +5° caster, and about 1/16" toe in should work well for most street applications.

How did you set the length on the adjustable strut rods? Hopefully you cycled the suspension through its range of travel to make sure nothing was binding. The alignment shop most likely won't want anything to do with adjusting those.

Speaking of strut rods , I built a pair for the mag. force tubular front end I have . I originally used rubber bushings on the front /attached to the brackets I welded on the frame . I recently changed the rubber to a heim joint on the front , already had a heim on the rear where it attaches to the lower A arm. I did this because of the size of the rear lower A arm bolts. Too small for my liking.
Now that I`m getting new shocks to loosen the front end up, I`m wondering how I can eliminate some binding in the full travel range. Any ideas out there ??? Have even thot of going back to the rubber bushings ------
Wonder if a flexable shaft would make any diff.-trying to dream up something that will give a little and still help the lower bolts. ?????

 

[72bluNblu]

Speaking of strut rods , I built a pair for the mag. force tubular front end I have . I originally used rubber bushings on the front /attached to the brackets I welded on the frame . I recently changed the rubber to a heim joint on the front , already had a heim on the rear where it attaches to the lower A arm. I did this because of the size of the rear lower A arm bolts. Too small for my liking.
Now that I`m getting new shocks to loosen the front end up, I`m wondering how I can eliminate some binding in the full travel range. Any ideas out there ??? Have even thot of going back to the rubber bushings ------
Wonder if a flexable shaft would make any diff.-trying to dream up something that will give a little and still help the lower bolts. ?????

Totally different application. The magnumforce front ends that I've seen shouldn't need a strut rod at all.

The mopar torsion bar suspension needs a strut rod because the lower control arm has a single mounting point and the LCA itself is only captured on the back side by the torsion bar. Because of the design, the LCA can flex forward and aft, which would have a big effect on caster if not controlled. So the strut rod is there to limit the motion of the LCA. With a poly LCA bushing it also keeps the LCA from sliding backward on the pivot pin.

The Magnumforce LCA has two mounting points that are captured so there can only be rotational motion up and down for the LCA. So there's no reason for a strut rod at all. And adding one really wouldn't do anything for you, your concern about the LCA mounting bolt being undersized isn't mitigated by the strut rod. If strut rod is being loaded at all, the mounts are flexing, and that means damage is being done before the strut rod is involved at all.

 

[famous bob]

Totally different application. The magnumforce front ends that I've seen shouldn't need a strut rod at all.

The mopar torsion bar suspension needs a strut rod because the lower control arm has a single mounting point and the LCA itself is only captured on the back side by the torsion bar. Because of the design, the LCA can flex forward and aft, which would have a big effect on caster if not controlled. So the strut rod is there to limit the motion of the LCA. With a poly LCA bushing it also keeps the LCA from sliding backward on the pivot pin.

The Magnumforce LCA has two mounting points that are captured so there can only be rotational motion up and down for the LCA. So there's no reason for a strut rod at all. And adding one really wouldn't do anything for you, your concern about the LCA mounting bolt being undersized isn't mitigated by the strut rod. If strut rod is being loaded at all, the mounts are flexing, and that means damage is being done before the strut rod is involved at all.

A previous thread quite awhile back, the poster said his back lower control arm bolt broke backing out of his driveway/off camber, the early m.f. tubulars had 1/2" bolts , scares me. The trick I was / am , trying to do is to put "barely' any strain pulling forward , to help the pushing forces to not overcome the bolt. I hope u are right, but I don't trust that 1/2" bolt completely. I have ran the rubber set up for quite a while , just recently adapted the hiem joints to them. But do have a little binding in full range of motion, may go back to the runbbers .
I talked to m.f. quite a while back , and they told me they had had only one failure reported to them-------??

 

[BigBlockMopar]

To square-up the strutrods, I would measure the back or balljoints of both LCA's to a fixed point on the car rearward, or to the rearaxle maybe, and adjust both struts to measure the same (LCA-to-Axle) distance on both sides of the car.

 

[72bluNblu]

To square-up the strutrods, I would measure the back or balljoints of both LCA's to a fixed point on the car rearward, or to the rearaxle maybe, and adjust both struts to measure the same (LCA-to-Axle) distance on both sides of the car.

Nope. The job of the strut rod is not to ensure that the wheel is in the right place. Set the strut rod length to the shortest it will go without binding the LCA. More than likely they will not be identical side to side, that’s ok. These cars are not perfectly square, there’s a tolerance there. By far, the more important part is that the LCA moves freely without binding through its range of motion.

 

[BigBlockMopar]

Yes, I was thinking of a car that's reasonably square to begin with.

 

[72bluNblu]

Yes, I was thinking of a car that's reasonably square to begin with.

“Reasonably square” from the factory could mean suspension mounting points that differ by an 1/8” side to side. If you try to correct that with a strut rod, you will get binding.

When you set the alignment on your car do you set one side and then just copy the camber bolt positions on the other side and call it good? No, you set the alignment on both sides to get the same final alignment specs. Same deal with the strut rods. Sure, the lengths should be fairly close from one side to the other, just like the camber bolt positions. But more likely than not they won’t be identical. The actual length of the strut rod is less important than getting the LCA to move without binding. You have to do the length setting process on both sides independently.

 

[famous bob]

To square-up the strutrods, I would measure the back or balljoints of both LCA's to a fixed point on the car rearward, or to the rearaxle maybe, and adjust both struts to measure the same (LCA-to-Axle) distance on both sides of the car.

that wont work w/ the m.f. set up I have anyway, to fixed for that method.
No adjusting w/ the struts, just ins. for the lower a arm bolts-------