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Leaf spring overhaul: bushings, bolts, pads, coating, shackles


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This is a thread dedicated to my at-home overhaul of some 2wd MJ leaf springs I'll be using for an SOA conversion.  I'm into restoration type work opposed to full-on replacement if possible.  

 

First I scored some junkyard springs with a nice protective layer of gear lube/dirt on them :yes:  

9OaX1b9.jpg

 

The at-rest arch measurements were within 1/8" of each other, so even if they're not perfectly up to spec. they should at least be equal.  

 

 

First step was to cut away what was left of the shackles and the bolt/spacers at the top of those clamp thingeys (wish I would have thought to keep the stock shackles around... oh well.)  The clamps look to be riveted to the main leaf so unless I discover a problem further down the line I'll just be leaving them attached.  

uTuxeyBh.jpg

Correction: 3rd leaf, not main leaf (thanks Eagle)

 

 

It looks like I've found the replacement plastic wear pads:

http://replacement-pak.com/  They sell on ebay.

$_57.JPG

 

I'll be coating the contact surfaces with this stuff:

$(KGrHqJHJCQE8+1edTTpBPWf9ZVl7g~~60_57.J

And likely spray-bombing the final assembly with some semi-gloss black.  

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You're off to a good start. Good find on the pads -- I wish I had known about them when I was refurbishing a set of springs.

 

The rebound clamps are riveted to the third leaf, not the main leaf. To replace, I used 1/4" bolts and the smallest steel tubing I could find that would fit over the bolts -- don't remember if it was 3/8" or 7/16", but my best guess is 3/8".

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The rebound clamps are riveted to the third leaf, not the main leaf. To replace, I used 1/4" bolts and the smallest steel tubing I could find that would fit over the bolts -- don't remember if it was 3/8" or 7/16", but my best guess is 3/8".

I too used 1/4" bolts. For the spacer/tube, I found a hardened steel spacer/bushing/pin at the hardware store just down the aisle from the grade 8 hardware.

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A-man, please document this restoration with lots of step-by-step pics. This is the type of DIY project that belongs stickied forever  into the DIY forum. It will help a lot of us down the road.  :thumbsup:

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Happy to document, just can't promise how quickly they'll get done  :D

 

 

In an effort to have the disassembly removal go a little easier I've got some Deep Creep soaking into the bushings and the center bolt areas.

vcug7guh.jpg

 

CJlq7TDh.jpg

 

 

And if you've never tried, yes it does help to clean dirt/junk off threads.  

 

0Pr4Jjqh.jpg

 

ojie1aqh.jpg

 

 

Thanks for the replies guys!  

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Those springs look as good as new.

 

Last year I took leaves and parts from four different springs, all of which had broken leaves, and mixed and matched to put together two complete springs. I'm in the rust belt, so I had a lot more work than you're facing. Center pins could not be salvaged. One I had to cut off. The other I was able to get the nut off after using a nut buster on the nut, but the shank was bent. I used socket-head cap screws from Lowe's, but (as others have pointed out) the heads are too large and need to be ground down slightly.

 

In the process, I discovered that there are two different types to those rebound clips (the straps riveted to the third leaf). There are short ones, that leave the cross pin sleeve basically in contact with the main leaf, and there are "tall" ones that leave enough gap for an additional leaf. I have no idea why the difference. It might be for different rate springs, or it might be a difference in the year of manufacture.

 

The leaves I was working with had so much rust flaking that I had to work on them with a ball pein hammer and a cold chisel to knock the flakes off. Then I swabbed them with rust killer. Once that dried, I gave them three coats of black Rustoleum, and put them back together.

 

The unloaded arch seems to be the same for both springs but, because of the mix-n-match origin, I don't know if they are the same spring rate. I hope so -- although I also hope I never have to use them.

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We've got a fair selection of press "accessories" at work, so hopefully I'll be able to find something that fits in there just right. The lube soaking in there for a week or so can't hurt either. I'm ready to torch them out if need be.

 

So I'm actually cheating a bit on the whole "at-home" part of the project... but nothing too fancy going on.

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Not my favorite idea either; I'll drill holes in the bushing and try to fold in or cut the shell of the bushing with an air chisel before the flames of justice are lit.  

But if push comes to shove the rubber will melt/burn out of there at a reasonably low temperature... We've done it at work with seemingly no ill effect.  

 

Hopefully I'll have time to try it out this week.

 

Jeep Driver

Was the rubber part of that bushing that screwed up or is that your doing?  

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Got the flange on the forward bushing folded up out of the way a bit, also pinched in the rear bushing "shell" as best I could with the chisel I had.  Another day or so of soaking in Deep Creep and I'll give it a try on the press.   :crossfingers:

 

GdNVsoRh.jpg

 

RyUgv0Sh.jpg

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Gave it a whirl today. 

 

0AJ7UV4h.jpg

 

 

YFePcW1l.jpg

 

BINGO!  All it took was a 25 ton press and some sweat!  :chillin: 

 

WgJ5xMuh.jpg

 

C0ssMomh.jpg

 

For those who don't have access to a press, you can pretty easily find a shop that will do this for you for a nominal charge.  

 

 

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Replacement bushings (by catalog) should be MOOG #SB372 and SB371 or Napa #2747056 and 2747058.  

 

 

 

I hear that replacement plain rubber bushings for the stock shackles are pretty well non-existent, is that correct?  As much as I like the build quality of JKS products I don't want the additional lift their shackles will give; I'll try and find some stock shackles if replacement bushings can be found.

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Gave it a whirl today. 

 

0AJ7UV4h.jpg

 

 

YFePcW1l.jpg

 

BINGO!  All it took was a 25 ton press and some sweat!  :chillin: 

 

WgJ5xMuh.jpg

 

C0ssMomh.jpg

 

For those who don't have access to a press, you can pretty easily find a shop that will do this for you for a nominal charge.

Holy crap!

 

That's a bearing puller, not a press plate. At 25 tons, I'm amazed that you didn't destroy the bearing puller. You were lucky ...

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That's a bearing puller, not a press plate. At 25 tons, I'm amazed that you didn't destroy the bearing puller. You were lucky ...

 

I've always heard it called a bearing splitter... either way that thing has been through hell and back here at the shop and she keeps on going.  And there's no gauge on our press so I can't say how much pressure was actually on it.  It got the job done!

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There's nothing show in the MJ parts manual for anything sandwiched between the perch/spring or u-bolt/plate/spring. However I did sandwich a 3* steel wedge between the leaf and axle perch to correct my pinion angle.  :thumbsup:

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