1973 Dart Suspension rebuild

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Old Mopar Man

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Greetings, first I liked to thank all folks that have shared their thoughts and advice in regards to my questions on rebuilding/upgrading the suspension on my 73' Dart Swinger on other threads.

I am reaching out as I believe I am asking my questions in fragments. Before I ran off and try and buy my way out the problems I having with the steering and suspension I wanted to solicit some thoughts on what I am experiencing as I drive the car.

The car has the standard factory suspension in the front w/disc brakes. The rear is leaf springs with adjustable shackles and air shocks. I bought the car with this set up. Most likely to fit the current set of P275/60R15 tires under the rear wheel wells. If I don't keep the air shocks filled, I get tire rub, additional, there is only about 1" space between the tire and the leaf spring. I like the big tires, but will trade for function. I pulled the front tires and checked the steering components for any obvious worn, bent or broken parts and nothing stands out.

The car steers ok when accelerating, but there is about a couple inches of play in the wheel. As the car slows I have to do a lot of over steering to keep in moving in a straight line. Other than going for a quick spin in the neighborhood I would not take the car on a road trip.

Here is my plan - rebuild the front end parts - BJs, TREs and upgrade to 1.03 TBs all with poly bushings. It seems most folks are also replacing the Pitman arm?

I really welcome some advice on the rear suspension - what will work best for the 8 3/4, coil overs and rear sway bar? As well as front and back tire suggestions.

Also don't want to break the bank on getting it to drive straight and handle better.

Any suggestions would be greatly appreciated especially in regards to the most likely causes of the steering and handling issues (assuming it has something to do with worn out parts and the way the rear is set up)?

Here some pics so you all can see how the car sits currently.

Thanks,

OMM

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My 73 needed upper and lower control arm bushings (they were factory).
I replaced the power steering box and upper/lower ball joints as well as tie rod ends. Factory tight now. My pitman arm is still factory. I replaced my rear springs too, but I'm running 14's.
 
1.SHOP MANUAL if you do not have. MANDATORY!!!! And, they are free!!!! Go to MyMopar and download one. That one, and several others at that site were made possible by several guys right here!!!

MyMopar - Mopar Forums & Information - MyMopar Tools/Reference

2....Wear parts:

Upper, lower ball joints
Upper A arm bushings
Lower control arm bushings
Strut rod bushings
Anti Sway bar bushings if used, both the bar itself and the links
Four tie rod ends
Idler Arm
Pitman Arm.

3..In addition, inspect for general wear and cracks, bends of steel parts This IMPORTANTLY includes the torsion bar anchors, the upper and lower arms, as well as the frame stubs and K member.

ESPECIALLY examine the lower control arm pivot pins and the mating holes in the K member

4...Alignment

If you are using radial tires do NOT use the factory alignment specs. Instead, go to AllPar.com and use their "skoch" chart


Turn of the screw: front end alignment for performance on classic Mopars

Read this thread, and post no2

duster alignment

289d4j7.jpg
 
1.SHOP MANUAL if you do not have. MANDATORY!!!! And, they are free!!!! Go to MyMopar and download one. That one, and several others at that site were made possible by several guys right here!!!

MyMopar - Mopar Forums & Information - MyMopar Tools/Reference

2....Wear parts:

Upper, lower ball joints
Upper A arm bushings
Lower control arm bushings
Strut rod bushings
Anti Sway bar bushings if used, both the bar itself and the links
Four tie rod ends
Idler Arm
Pitman Arm.

3..In addition, inspect for general wear and cracks, bends of steel parts This IMPORTANTLY includes the torsion bar anchors, the upper and lower arms, as well as the frame stubs and K member.

ESPECIALLY examine the lower control arm pivot pins and the mating holes in the K member

4...Alignment

If you are using radial tires do NOT use the factory alignment specs. Instead, go to AllPar.com and use their "skoch" chart


Turn of the screw: front end alignment for performance on classic Mopars

Read this thread, and post no2

duster alignment

View attachment 1715294600
Great post.
I also would be budgeting for a new steering box, you can adjust yours to a point to try it and that might be enough.
I would change the rear suspension and definitely get rid of the air shocks.
You need to mini tub the car and weld in offset spring mounts to run that big of a tire in a Swinger.
I would also look at Super Stock springs or XHD springs as well.
 
Measure where the tire is in the wheel well and get wheels with the right offset to center them.
 
Measure where the tire is in the wheel well and get wheels with the right offset to center them.

275's still won't fit on a factory 73 Dart with the factory 4.5 backspace.
I had to move my springs in 1/2 inch and trim the fender lips just to fit 9.5 inch rims and 245's.
Then the the tub is the limitation after that.
New wheels with a perfect offset for centering the tire in the well and they just barely touch the tub on a corner while going through a dip.
 
Last edited:
I went mini tub, moved the springs under the frame and trimmed the fender lip and narrowed my axle.
I clear 295X65x15s

I could go bigger but would.need more back space.
 
Hey all,

Awesome advice and insights.
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Roy, I live just live outside Hinesville, GA, in farm country, I thing we exchanged texts on axle housing you had for sale? As Far as the rear tires are concerned thinking about running BF Goodrich Radial T/A Tire P235/60R15 in the rear and BF Goodrich Radial T/A Tire P225/60SR15 up front. Not sure I want to relocate springs and adjust the wheels wells to fit these bigger tires. How about rear coil overs and Anti Sway Bar with the less wide tires? Or will the 15's tire still create issues with fitting in the wheel wells or maybe able to correct with offsets?

I do have the shop manuals, but appreciate the link and will download to have on my laptop for on the go information.

Tracking all on parts inspection and investing in a new steering box, currently no Anti Sway bar up front, thinking with the headers that it will not fit. It may limit my options for adding a ASB. In regards to the lower control arm pivot pins and the mating holes in the K member, what is the best methods to fix? Or do you have to replace the K-Member?

The trick will be to find someone locally that understands the older suspension and can use the "skoch" chart to guide the alignment.

I greatly appreciate you all taking the time to share knowledge and experience. This is going to save me a lot of time and hopefully resource as I go forward with the repairs.

Thanks!

Ed
 
Just align it your self.

I got the Joe's racing camber caster tool from summit for 120 bucks. It's very nice and did a great job.

Took about an hour.

When I rebuild my front end I'll get the off set ball joints and try for to get the camber better.

Best I could get was +3 caster and -1 camber. If I remember correctly?

I can bet you the kid at the alignment shop wont try as hard as you.

Although I was more concerned about caster as I want my car to track good and tire wear is secondary.
 
I have a second home in Perry Ga. and thought we might be closer to each other and I could lend a hand. On a 71Dart bracket car I raced, I moved the springs into the frame rails and was able to get a 29x10.5Wx15 slick under the car with 002/003 Super stock springs. This IMO is the easiest way to get a big tire under a swinger body.
 
Gentlemen, thanks for for the feedback. I will be reaching back as I move forward on the rebuild.

I have some time in April to finally get wrenching on Dart. It should be an adventure of discovery. By the look of it the front end has either original parts or at least they been on the vehicle sometime.

Thanks again!
 
20190126_142509_zpstj6wsn9p.jpg


SS springs under the frame.
Spring sliders
Narrowed 9"
4.88 w spool.

Priceless
 
How about rear coil overs and Anti Sway Bar with the less wide tires?

You've mentioned rear coil overs twice, but I'm going to assume you're talking about booster or overload shocks and not true coil over shocks. In my opinion, they are a cheap band aid fix at best and put undue strain on your upper shock mounts that they weren't designed to take. Your best money would be spent on getting a good set of leaf springs under the car that set it at whatever ride height you want. You can order stock, +1", +2" etc. There are dozens of threads here talking about different brands and number of leafs, I'll let you look them up. Once you get a decent spring under the back, you may not feel the need for a rear sway bar.
 
275's still won't fit on a factory 73 Dart with the factory 4.5 backspace.
I had to move my springs in 1/2 inch and trim the fender lips just to fit 9.5 inch rims and 245's.
Then the the tub is the limitation after that.
New wheels with a perfect offset for centering the tire in the well and they just barely touch the tub on a corner while going through a dip.

Until you measure and find your centers you cannot make good decisions on wheel offset and how wide a tire you can fit. I have done this on the Barracudas. Your experience sounds good.
 
Until you measure and find your centers you cannot make good decisions on wheel offset and how wide a tire you can fit. I have done this on the Barracudas. Your experience sounds good.

I spent literally months rethinking and remeasuring to finally get what I wanted.
Literally hours and hours of pics online and different wheels are saved to my computer, and I must have Photoshopped 50 different wheels on my car.

Measured all the dimensions like wheel mount surface to leafs, wheel mount surface to outer fender lip, wheel mount surface to both inside and outside of the wheel house, and then drew a diagram with all those measurements.
I wanted wheels and tires to fill out the wheel well and get both as far to the outsides as I could get them because I didn't like the way the rears were tucked back inside the fender.

The 18 inch Ridler 695's I finally ordered had 5.5 backspace with a 9.5 inch rim.
Problem was I had exactly 5.5 inches from the wheel mount surface to the leafs.
I knew this going in and knew I was going to have to deal with it.
The tires are Nitto 40 series with a square edge profile and 9.5 inches of tread area, so the rims are exactly the width of the tires (because I wanted all the wheel I could get in there to show off a nice wide machined outer surface from the spokes to the rim edge.

Apparently I went about doing the spring move different than most.
I will be changing to a 8.25 sure grip so for now I slotted the spring perches holes so I could slide the springs in .5 inch.
Then took the rear hangers off and drilled them with new holes to move them to the inside right next to the frame rail (maybe 1/16 to 1/8 from the shackle bolt heads to the frame rail)
There was a little more to the rear brackets, but it's hard to explain without pics of how it was done.

On the front hangers I cut the top 2 studs off and slotted the bottom holes in the body and then marked and cut a square hole in the frame rail so the front eye big bolt head could recess into the frame rail.
The slotted holes let the bracket slide over so the bolt head went in the hole and then I drilled the center of the bracket and added a 1/2 bolt, washers and nut through the bracket and bracket mount surface.

Doing all this gave me 6 inches from the wheel mount surface to the leafs, so 1/2 clearance.
The wheels and tires are exactly centered in the wheel tub with 1 inch clearance on each side.
I also took 1/2 inch off the inner lip of the fender and wheel opening trim, by cutting just inside the screws for the trim, and then smoothed the cut down with a flap disc and sprayed the new edge with undercoat.
I can just barely get my fingers between the tire and inner lip now instead of having 2 inches there like before.

All in all I'm really happy with the way it turned out, but I sure wouldn't want to have to do it again any time soon.:D

The ride height pretty much has to be where it is due to the really shitty streets around here.
(In my opinion any street in a 25 mph speed limit area that can slam your K frame on the pavement with 1.03 torsion bars should be against the law):D
I recently added KYB monotube shocks on the front to help with that, and it did.

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Gentlemen,

Got me spinning. I need to do some more homework, especially on thinking through the rear suspension and what wheels will fit and still give me better handling and keep looking like a hot rod.

Good with keeping it basic with a good set of leaf springs and shocks. The wheels and rims are more of challenge. Back to part, wheel and rim research.

Be back when I find a parts combo that will improve the handling and hopefully not break the bank.

Thanks again for all the great feedback.
 
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