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Adjusting the ride height for a 1975 valiant

Discussion in 'A Body: Duster, Valiant, Dart, etc' started by core, Jul 14, 2013.

  1. core

    core Member

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    I am trying to figure out what the original ride height was for a 1975 Valiant. The car is sitting on a level floor.
    I put a level on the threshold of the door and it is a full bubble off. The front of the car is sitting higher than the back.
    Is that how it is supposed to sit?

    I'm installing the rearend and the perches need to be welded into place.
    Can the ride height be adjusted after the new rearend Is installed, or should the ride height be adjusted first?
    What is involved in adjusting the ride height?
     
  2. valiant67

    valiant67 ...

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    There are two things to consider. First, the front ride height is adjustable by turning the bolts on the torsion bar anchors. Second the rear ride height is adjustable by modifying the springs (reaching, adding leaves, etc.).
    The proper way to measure ride height is given in the service manual which is measuring form the ground to certain points on the car undercarriage.

    Generally as the car ages, the rear leaf springs tend to sag so it would not be uncommon for the rear to be lower than it was when new.
     
  3. dana44

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    Agree the rear leaf springs are more than likely sagging, and yes, the front should be adjusted first, which could actually throw off the pinion angle of the newly installed rear end. Start by determining if the front end is at the proper height when everything is installed, being running gear, interior and body and a full tank of gas. This gives normal ride weight to adjust. Start with the torsion bars, and if you have the factory settings, which I believe the book will indicate is a distance between the lower control arm and the lower control arm rebound bumper, adjusting and then bouncing the car several times at a fender corner and rechecking it. I personally find one finger thickness the best setting, makes cornering better. Once the front end is set, then determine the pinion angle of the rear end and use your level if you want to see how the rake of the body is front to rear and whether or not re-arched rear springs or replacing some of the other leaves to beef up the original eyelet leaf to give more rise in the rear.
     
  4. ImperialCrown

    ImperialCrown Moderator
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    You will want to set this by the procedure and spec stated in the service manual. A good public library may have 1970's Chilton's, Mitchell's, Motor's or even a factory manual on your car.
    The general practice was to set tire pressures with a full tank of fuel, no occupants or luggage, jounce the car on a level surface (push down firmly on the front bumper with your knee, release and let it settle where it stops).
    The spec is measure from the front torsion bar anchor to the floor. Same on both sides. The alignment should be checked as well as the height set will change alignment angles and toe. In fact , it is best to do the rear springs at the same time as all this.
     
  5. tazdevil

    tazdevil Member

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    Before adjusting the T bars, I think that replacing the rear springs is critical, They are most likely sagging below factory specs. Once they are installed, set the front T bars to the correct setting. I recommend the replacement Mopar set for good height. Super stock springs will raise the rear height about an inch.
     
  6. core

    core Member

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    Looking at the car the rear tires looked to be sitting in a good position. It was the front that was elevated.
    The adjusting bolt for the torsion bars was just about all the way up.
    I turned the bolts until the front end came down and looked normal. From the floor to the invert of the torsion bar anchor I ended up with
    7 3/4".
    I have the service manual set for the car. I could not find heights for adjustments.
    Are the factor ride height critical or can they be played with?
    I have changed the motor and transmission from the original slant six and lighter tranny. Does that make a difference?

    Is there a way to tell if the leaf springs have sagged?
    After I adjusted the torsion bar the car door's threshold was level.
    Does that matter?
    After setting the pinion angle and installing the drive shaft. Can ride height be readjusted if needed with the help of shims.
    Thanks for the help
     
  7. dana44

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    The factory books should show something either in the front suspension portion or the body measurement location in the back of the FSM. Same for the rear springs, some kind of measurement of ground to body point location clearance. As far as changing items after the rear end is set up, getting it up with the rear on the ground, sitting on the leaf springs will give the proper angle, and from there, slight adjustments front or rear are still within the normal range of travel and should not be an issue, I think I said otherwise earlier and was wrong.

    Ride height can be changed in the front to compensate, your book may indicate a torsion bar diameter for slant six and 318 and 360 being different. The larger the diameter the bars, the stiffer the suspension will handle (and corner better, trust me on that). The ride height is adjustable, something I mentioned the preferred ride height I like for handling, especially when you get above 60mph. Basically what I figured out was, if the ride height is set to factory height, little bumps make the front end float. I spent three weeks adjusting my bars on my 68 Charger a little bit at a time until I safely got the torsion bars to a location between the lower control arm and its rebound bumper to a gap of 3/4 inch. Less produced a harsh ride, more made the front end start floating because more air was getting under the front of the car and a bounce or dip in the road made things worse. At 3/4 inch, the front end sits down, bounces respond quicker, and corners are flatter since the front end has farther to travel and the swaybar then works sooner. With my 68 I then decided to purchase new larger bars on top of what I had learned, to which I was able to set the bars at the gap I like and it was simply an improvement over what I liked to begin with.
     
  8. ImperialCrown

    ImperialCrown Moderator
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    Height changes will affect the front end alignment (and headlamp adjustment). Have it rechecked or else you may start wearing tires.
     
  9. tazdevil

    tazdevil Member

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    Good point. The camber dimension changes with torsion bar settings. I, too messed with mine on the Demon before getting it right, then did alignment.
     
  10. valiant67

    valiant67 ...

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    I think the height measurements are usually in the Frame section, not the Suspension section.
     
  11. ImperialCrown

    ImperialCrown Moderator
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    The adjustment procedure and possibly the spec should also be given in the 'Pre-alignment inspection' section under Chapter 2 - Front suspension.
    I found the height spec on the last page of the Front Suspension chapter under Specifications.
    Lowering the car will also increase toe-in.
     
  12. TWX

    TWX DO NOT FEED THE TROLLS!
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    Having been in your shoes with the Cordoba, I'd first verify that the front end isn't worn out to where you need new suspension components, then I'd set the ride height to level out the car, and after that I'd take it straight to an alignment shop and tell them to align it with the current ride height, giving a bit of positive caster, which will help with the steering self-centering as it drives.

    If you need to replace leaf springs or the like, then do that first, then do the rest.
     
  13. core

    core Member

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    Taking a fresh look at the manual today I was able to find the floor to anchor bolt height. It is 10-15/16".
    I had adjust the height yesterday until the car looked good and i ended up at 11-1/4".
    I have no idea why the torsion bars were so far off, but an alignment is going to be need.
    I'm going to do a dry run installation of the rear end, with the perches not welded on and readjust the ride height.
    Thanks again for the help. I would not be able to do this project with out this forum.
     
  14. Dave Z

    Dave Z It's me, Dave
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    I was fortunate enough to get an experienced mechanic when I took my car in for adjustment and alignment at the dealer five or six years ago. He did an incredible job — the car felt as though it had been upgraded to a new suspension when he was done adjusting and tweaking. It really makes a huge difference, getting it right. But yes, alignment has to be done afterwards!

    You might want to look at dana44’s posts again before basing the height on looks and having it aligned.
     

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