rear springs up front? (1 Viewer)

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I have some ext. shackles and was planning on re-locating my spring hanger to improve my shackle angle. I know some mini owners throw the longer rears up front, can I do the same?

Is it just blot on and go? The pin is about 1-2"s farther from the eye but it seems like that should be fine. Anyone else do this? pics?

thanks.
 

Spook50

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There's definitely some fab work involved. It's not a simple bolt on. I've looked into it and plan to eventually do it after I finish a few other projects. There's some info on here detailing it a bit more. When I do mine I plan to do it in conjunction with a shackle reversal.

What I have yet to find out for sure is, if a rear to front swap is done in conjunction with a shackle reversal, if the angle that the springs hold the axle (in comparison to the angle of the front springs with a factory shackle configuration) will have the caster in a range close enough to be adjusted with shims. It'd be great, though I'm not counting on it. I'll be anticipating a cut & turn just in case.
 
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Yeah but that's the thing, longer but the pin is the same from the eye so the axle wouldn't move. Spooks point on caster makes sense though.
 

Spook50

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Yeah but that's the thing, longer but the pin is the same from the eye so the axle wouldn't move. Spooks point on caster makes sense though.

It's just something I'm not sure of, and wouldn't be until I can measure. It could pivot the axle in the right direction to make caster correctable with shims, or go clear the other way and make a cut & turn mandatory.

Hopefully one of the couple guys who've done this can chime in with some of their experiences.
 

GLTHFJ60

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Does anyone have a full set of 60 springs laying around? If someone could measure eye to eye length as well as double wrap end to pin length, a lot of our questions will be answered.

I could go out and measure the ones on my truck later today. That would probably yield the same effect.
 
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I measured as stated in the OP, the pin from wrap side off by only an inch or so, the extra length from pin to non wrap side would be eaten up by by ext. shackles. What we need is somebody who has done it to chime in.

Or else I'm going to swap and see.
 

GLTHFJ60

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How much longer is the stock rear pack than the front? If you used the right shackle you might not even need to move the perches.
 

Mace

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That'll be a hell of a long shackle..


You may want to redrill you stock perches (to ge the axle centered in the wheelwell) and add some additional leaves to the pack to help support the motor.

Longer spring packs make each leaf hold less weight.

I'm not really sure I see the benefit of what you are doing tho. Is it for ride quality? Or for increased articulation?
 
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articulation is what I see going on here.....


I just got done doing the 63 chevy springs on my friends fj55. we put the stock rear springs up front and 63 chevdogs on the rear... we had to reweld all mounts. although, we did have 60 axels under it.

The articulation is sick and a super soft ride to boot.
 

GLTHFJ60

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That'll be a hell of a long shackle..


You may want to redrill you stock perches (to ge the axle centered in the wheelwell) and add some additional leaves to the pack to help support the motor.

Longer spring packs make each leaf hold less weight.

I'm not really sure I see the benefit of what you are doing tho. Is it for ride quality? Or for increased articulation?

With longer spring packs you gain both articulation and ride height, no? I thought that was the reason people switch to 63" chevy springs, for example.
 

Mace

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Articulation is not just based on the length of the leaf spring. You really have to look at the entire front end as a whole. This may be a portion of it. I do not know. Shocks tend to be the worst limiters of suspension travel, then its the brake lines..


As far as height, given two identically designed springs, with the only difference being physical length of one of the springs, the longer spring will have less of a spring rate than the shorter spring (that's why Add a leafs are short).

Think of it as a lever.
 
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Seen some of the 70 series guys do it, try searching there as well. They just used a really long shackle to avoid any frame mods for use on Aus roads. Seemed to work out ok. Some of the 70's came with the same spring lengths as 60's btw.

example:
https://forum.ih8mud.com/70-series-tech/241664-mighty-short-cruiser-9.html
and
https://forum.ih8mud.com/70-series-tech/269633-red-barron-fj73-middy.html

sweet! thanks for the links.

Here are the pics, I'm doin it. Unless somebody chimes in with some reason or logic.
sprangs.jpg
sprang1.jpg
 

GLTHFJ60

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Definitely do it. A longer shackle would make it work well as long as everything else is set up to flex like the springs will.

Are you planning on taking some leaves out of the packs? I would assume at least the bottom 2.
 
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You may want to redrill you stock perches (to ge the axle centered in the wheelwell) and add some additional leaves to the pack to help support the motor.

Longer spring packs make each leaf hold less weight.

Are you planning on taking some leaves out of the packs? I would assume at least the bottom 2.

gonna start with a full pack with short AAL and work my way down.
 

Spook50

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gonna start with a full pack with short AAL and work my way down.

When putting the rears on the front, remember they now have to support alot more weight 100% of the time. Were it me, I'd start with the full pack plus a full length AAL in each pack first. Even that might not be strong enough to prevent sagging.

I'm anticipating having to put two AALs in each pack when I do it (I've got a set of four so once I put the Chebby 63" rears on, I'll be able to hijack leafs from my front packs when I move the OEM rears up).
 

lcwizard

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When putting the rears on the front, remember they now have to support alot more weight 100% of the time. Were it me, I'd start with the full pack plus a full length AAL in each pack first. Even that might not be strong enough to prevent sagging.

I'm anticipating having to put two AALs in each pack when I do it (I've got a set of four so once I put the Chebby 63" rears on, I'll be able to hijack leafs from my front packs when I move the OEM rears up).

Actually, at least among aftermarket 60 springs, the 60 is different than the 40 in the fact that the spring rates are about the same front and rear, so ride height will be determine by comparing the free arch between the two. If setting the two side by side on the ground and the rear is taller with no load, and the springs rates are the same, you should see some lift.
 

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