Author Topic: Leaf Spring Replacement  (Read 7735 times)

Offline 7212Mopar

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Leaf Spring Replacement
« on: August 01, 2013 - 07:05:24 PM »
I read through most of the older threads concerning replacing the rear leaf springs. It does not sounds like an easy job at all and this is my first attempt. I am at an age of diminishing muscle power so I will find myself a long breaker bar and try not to twist the bolts off. I got the Mopar springs (made in Mexico), the rear rubber bushings and new U-bolts. However, I have not purchased new shackles or mounting bolts. I guess I will find out when I get on it tomorrow. From the old threads, I did not see any mention on specific torque requirement when bolting the assembly back. Anyone knows what it should be?
1973 Challenger Rallye, AT with 1971 340
2012 Challenger SRT8 392 YJ,  6 spd




Offline Bullitt-

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Re: Leaf Spring Replacement
« Reply #1 on: August 01, 2013 - 08:39:28 PM »
Tighten with weight on the wheels

73 Service Manual says in foot pounds
Center Bolt Nut....40
Front Hanger Nut..30
Pivot Bolt or Nut..125
Rear Hanger Bolt..30
Shackle Nut.........40
U Bolt Nut...........45....for 7-1/4 axle..40
Rear Shock Lower.50    Front Shock Lower.50
    "           Upper.70           "         Upper.25

Rear Sway Bar measured in inch pounds
Shaft Bracket Retaining Screw...200
Link Nut.................................100

« Last Edit: August 01, 2013 - 08:41:59 PM by Bullitt- »
Wade  73 Rallye 340..'77 Millennium Falcon...13 R/T Classic   Huntsville, AL
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Offline 4Cruizn

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Re: Leaf Spring Replacement
« Reply #2 on: August 01, 2013 - 08:50:14 PM »
I read through most of the older threads concerning replacing the rear leaf springs. It does not sounds like an easy job at all and this is my first attempt. I am at an age of diminishing muscle power so I will find myself a long breaker bar and try not to twist the bolts off. I got the Mopar springs (made in Mexico), the rear rubber bushings and new U-bolts. However, I have not purchased new shackles or mounting bolts. I guess I will find out when I get on it tomorrow. From the old threads, I did not see any mention on specific torque requirement when bolting the assembly back. Anyone knows what it should be?


It's been awhile since I put in new springs  but if I can do it . . . Anyone can!   Everything came apart pretty easy though . . . .

Offline anlauto

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Re: Leaf Spring Replacement
« Reply #3 on: August 01, 2013 - 09:28:47 PM »
Save yourself hours and hours of frustration and just cut off the U bolts and replace them :2cents:
I've taught you everything you know.....but I haven't taught you everything I know !
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Offline Jesus H Chrysler

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Re: Leaf Spring Replacement
« Reply #4 on: August 01, 2013 - 10:29:28 PM »
 :iagree:  I don't know where you or the car are from, but here in the rust belt it's pretty pointless to save the U bolts.  Shackles can be saved with liberal use of PB Blaster and/or heat.  FYI the Mopar springs tend to lose their "spring" after a while so keep an eye out for sagging.
Yes I own a 1972 Dodge Challenger Convertible T/A S/E with a 440 Six Pak. Can it get any more wrong?

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Greg, in the middle of MA has:
1970 Dodge Coronet 440 "Zom Bee"
1972 Dodge Challenger convertible 440 5 speed.
1973 Dodge Challenger 318 "Brown Bomber"
2012 Dodge Challenger R/T Classic Blackberry Pearl.
2001 Jeep Wrangler locked, lifted and lighted.  "Jeep is a registered trademark of Chrysler Corporation"

Offline 7212Mopar

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Re: Leaf Spring Replacement
« Reply #5 on: August 02, 2013 - 02:17:59 AM »
Thanks everyone. I do have new U bolts but not new bolts at the hangers. Car was originally sold in San Jose CA and spent time in Oregon. The last time I looked, it was not too rusty. Know more when I get started tomorrow. As far as tighten with weight on wheels, I suppose it is same with weight of the car on springs and supported at axle with jack stands or geometry not the same? Since I don't have a lift, not sure I can reach the bolts with the wheels on the ground.
1973 Challenger Rallye, AT with 1971 340
2012 Challenger SRT8 392 YJ,  6 spd

Offline Bullitt-

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Re: Leaf Spring Replacement
« Reply #6 on: August 02, 2013 - 07:59:09 AM »
As far as tighten with weight on wheels, I suppose it is same with weight of the car on springs and supported at axle with jack stands or geometry not the same? Since I don't have a lift, not sure I can reach the bolts with the wheels on the ground.

Yea that should be fine, just wanted to give you fair warning. 
Wade  73 Rallye 340..'77 Millennium Falcon...13 R/T Classic   Huntsville, AL
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Offline Road_Runner

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Re: Leaf Spring Replacement
« Reply #7 on: August 02, 2013 - 05:12:43 PM »
Last time I did this in the driveway I used two sturdy jacks, one under each frame in front of the forward leaf spring mount.  When you take off your tires put them under the car  in front of the jacks as well just in case the car falls off the jacks while you're working.  I then used a floor jack to lift the weight off the center of the rear end, then on one side unbolted the shocks, ubolts rear shackles then front leafspring eye bolt.  Install in opposite order of removal, then when you're finished with one side do the other.  You may have to tweak the floor jack to help keep tension off the leaf springs until both ends are re-attached.  That's how I did it.  I can soooo relate to not being as strong as I used to be.  In the past I've installed transmisions by myself without a jack .... probably won't be doing that again!  Good luck & be safe!!!

Later, Jim
1970 383 Roadrunner Tor Red
1973 318 Barracuda Mist Green
2014 Mustang GT/CS Convertible All Black

Offline Chryco Psycho

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Re: Leaf Spring Replacement
« Reply #8 on: August 02, 2013 - 06:24:33 PM »
You will probably need new spring eye bolts too , they usually sieze in the front bushing so you have to grind the bolt off to remove the front mount , I would use a grade 8 bolt & lock nut to replace the factory one & coat the bolt with anti sieze .

Challenger - You`ll wish You Hadn`t

Offline 7212Mopar

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Re: Leaf Spring Replacement
« Reply #9 on: August 05, 2013 - 02:27:21 AM »
Ok, another one (that would be me) bite the dust. I thought my old leaf springs were sagging since the back is lowered than front. So after putting in a new set of Mopar XHD springs, the height is the same as before  :banghead:. Search some more old threads and concluded my old springs were not sagging (XHD springs do not raise the ride height). I understand air shocks are no no and I am not motivated to take it apart again soon. The rear sits 23-5/8" and front 25-5/8" to the fender lips. At this point, I am thinking to lower the front so that front and back is about the same height (pro touring look?). I suppose lowering the front two inches by cranking down the torsion bar adjusting bolts will change the alignment. Anyone know a good alignment shop that knows classic Mopar located in the SF Bay Area?
1973 Challenger Rallye, AT with 1971 340
2012 Challenger SRT8 392 YJ,  6 spd

Offline dodj

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Re: Leaf Spring Replacement
« Reply #10 on: August 05, 2013 - 06:17:45 PM »
As far as sagging goes, on a Challenger, about 1" to1 1/2" of the rear tire is up inside the wheel well at stock height.
Scott
1973 Challenger  440 4 spd 
2007.5 3500 6.7 Cummins Diesel, Anarchy tuned.
Good friends don't let friends do stupid things. ........alone.

Offline brads70

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Re: Leaf Spring Replacement
« Reply #11 on: August 05, 2013 - 07:25:16 PM »
I didn't care for the stock saggy bum look either so I used plus 1 1/2" springs from ESPO . They worked great for me, had them on the car for 2-3 years till I went with composites.
Brad
1970 Challenger 451stroker/4L60 auto OD
Barrie,Ontario,Canada
Proud to own one of the best cars ever made!!!!!

My restoration thread 
http://www.cuda-challenger.com/cc/index.php?topic=59072.0
 My handling upgrade post
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Offline dodj

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Re: Leaf Spring Replacement
« Reply #12 on: August 05, 2013 - 10:03:13 PM »
I didn't care for the stock saggy bum look either so I used plus 1 1/2" springs from ESPO .
The other option is the way I went, and dropped the nose until I didn't have the saggy bum look.  :grinyes:
Scott
1973 Challenger  440 4 spd 
2007.5 3500 6.7 Cummins Diesel, Anarchy tuned.
Good friends don't let friends do stupid things. ........alone.

Offline Jesus H Chrysler

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Re: Leaf Spring Replacement
« Reply #13 on: August 06, 2013 - 08:53:24 AM »
The other option is the way I went, and dropped the nose until I didn't have the saggy bum look.  :grinyes:

I did that.  In New England, the roads suck and they love speed bumps.  My Challenger with the homemade frame connectors got a lot of scrapes.  And the handling sucked.  Better off trying lifted springs in the back.
Yes I own a 1972 Dodge Challenger Convertible T/A S/E with a 440 Six Pak. Can it get any more wrong?

{OO /===\ OO}
(OO==> <==OO)



Greg, in the middle of MA has:
1970 Dodge Coronet 440 "Zom Bee"
1972 Dodge Challenger convertible 440 5 speed.
1973 Dodge Challenger 318 "Brown Bomber"
2012 Dodge Challenger R/T Classic Blackberry Pearl.
2001 Jeep Wrangler locked, lifted and lighted.  "Jeep is a registered trademark of Chrysler Corporation"

Offline 7212Mopar

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Re: Leaf Spring Replacement
« Reply #14 on: August 07, 2013 - 01:02:12 PM »
Ok guys, you are confusing me. So I am going to do both. Drop the front a bit. I figured one or two turns will not affect the alignment much. I also ordered a set of Hellwig EZ550 helper springs from Summit so I don't have to take it apart again. It will go to the back half of the spring only. It is supposed to be adjustable depending how tight you torque the bolts. I probably try to salvage the plastic spacers from my old springs place under the helper springs to avoid any squeaking sound. Will see how that works out this weekend. My quest for better butt posture continue.
1973 Challenger Rallye, AT with 1971 340
2012 Challenger SRT8 392 YJ,  6 spd