FJ40 Leaf Spring Issues....

brakes-shocks-lockers-etc
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nzdncjw
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FJ40 Leaf Spring Issues....

Post by nzdncjw »

Hey there... I have had a look around but have been unable to find an answer to my problem.... so here is the problem.... By the way I own a 1980 SWB FJ40 Toyota Land Cruiser....

The problem is I believe the rear leafs and the front to the lesser extent are too short. You will see in the photos below a b4 and after photo - the after is a digital correction by myself of what I believe the spring setup should look like with maybe more angle? Easy on the computer! hands didn't even get dirty and the job took 2-3min!!! if only!!!

Anyway, The before photo is as the truck sits on a flat surface loaded as I would drive it. My plan at this stage is to maybe....
One: Get a couple of leaf springs made up 2-3" longer than whats there (just the top couple) and replace the current ones
Two: Remove a couple of the smaller leafs to soften the ride which I also want to do - it is rock solid at the moment.

By doing just the first option my theory is I will put the shackle back in the correct position (after photo) and allow some downward travel - at present if I put my high lift under the back bumper I only have to do 3-4 lifts and the wheels leave the ground!

If I do the second option it will softent the ride considerably? BUT ALSO IF I just take a couple of leafs out from the bottom would that lessen the arch in the spring and therefore push the shackle to more of an angle? but would this be enough? I want maximum travel possible without changing mounts etc....

I thought I might try doing this first but what leaves and how many should I take out? I currently have 7 leafs... will double check tomorro...

Hope you understand my ideas and can confirm or shoot down what I think it right and wrong and hopefully point me in the right direction!!!

Thanks in advance!

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niblik
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Post by niblik »

your theories are sound as a pound fella..

try the 'remove leaf' theory first.. can take out possibly 3 from the bottom of the pack. also could try slightly shorter shackles. only if desperate though..

alternatively you could find some std springs off another cruiser that were just slightly longer... :wink:

let us know what ya do, and post pics.. :D
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nzdncjw
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Post by nzdncjw »

could I take three from front and back ok? would you just tke the bottom three out or would you miss one take one kinda thing? I'm gonna try that taking some out this weekend all going well.
thanks!!

Chris
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SupraLux
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Post by SupraLux »

When removing leafs, try and keep things even - don't pull them all from one point in the pack, try every second one - but generally try and retain the primary and second leaf (often military wrapped around the primary).

As for 40's, there are about 3 or 4 different lengths of spring pack for those - make sure you have the right model springs before you get too carried away modifying things...

Alternatively, throw 4 bags of cement in the back, that'll help push the springs flatter - used to do that in my old RX-engined subaru ute to make it handle better at speed :)

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nzdncjw
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Post by nzdncjw »

How do I know if I have the correct model spring packs for my truck? I'm gonna try removing a leaf or two and see how that goes.... but to check if I have the correct pack what do I need to do?

Thanks!
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Sadam_Husain
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Post by Sadam_Husain »

If your spring pack has been set too high your spring hanger would sit at the angle of your photo. One of my old FJ45's had the springs set too high :?

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nzdncjw
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Post by nzdncjw »

So my spring pack is set too high..... (':?') This weeks plan is to do sort it out... I have to somehow drop it 90mm.... thats the only way I'm gonna fit it out the garage without removing my roll cage again.... so by taking a few leafs out and letting the tyres down I should be sweet now.... thought it might be tight just doing tyres but the combination should be sweet!
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nzdncjw
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Post by nzdncjw »

Hello again.... Well I managed to remove one of my Springs tonight! Anyway.... I have the spring in my vise. they are Military wrapped in 3 spots, whats the best way to remove these to enable the removeal of a leaf or two....

The military wrap is wrapped on leaf 2, 4 and 5 I was thinking of removing leaf 1, 3 and 4. this would leave the 2 longest springs in place which would help with strength I would imagine? Also this would leave 2 of the 3 militay wrapped leafs in the pack.... Is 4 out of seven strong enough still?

Is the Military wrap only fixed to the one leaf? if so whats the best way of getting the wrap off? Any ideas as to the best way of doing this?

I worked out It is definitely not my shocks running out of length when I jacked the truck up there was still a good couple of inches of downward travel left....

Anyway I took a few photos.... here they are!



Image
This pic is of the leaf in full
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Seven Leafs all up
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Close up of the rear end of the Spring
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Close up of the Front end of the Spring
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H2OLOVA
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Post by H2OLOVA »

The wraps are normally welded together and yes they are only fixed to one leaf. Use a grinder with a cutting wheel or a hacksaw and cut through the middle of the top of the wrap. This way once you have remove the leaves the wrap can be refitted around the remaining leaves. You'll need to cut it down cause it will be too long with the leaves removed, and then reweld it together.

Easy peesy :wink: :wink:
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nzdncjw
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Post by nzdncjw »

The wrapps on my spring are not a full loop, they only wrapp around the bottom sides and about a quarter across from both sides on top - an upside down c shape. I have been told on another forum to bend them out to make a U shape as this will lessen the restriction of movement between the leafs.

When you say 'cut' where abouts do I cut? do I just cut the top section off to make the U shape and then re weld the tops on later when they are back together? Or just leave the bits off all together? Sounds easy enough if thats the case....

Thanks!
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H2OLOVA
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Post by H2OLOVA »

As mentioned through the middle on the top side, doesn't have to be precise at all. And they aren't always welded, so bending works just as well :wink: :wink: .The U shape thing is probably right in regard to restricting spring movement, but by making it a U shape you would almost negate the use of the wrap at all. But i don't know enough about wraps etc to have any helpful advise about that side of it.
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nzdncjw
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Post by nzdncjw »

awesome thanks for that... will have a play!

Chris
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;-p

Post by wopass »

just bend them open to do what you want to do then bend them back again but leave them fairly open over the top, this gives the pack freedom to move.

i think i have 6 leaves in the rear of mine, the 45's from memory have extra load springs for ....extra loads :roll: so removing 1 would be fine, i wouldnt remove too many tho as the pack strength stops your axle wrap.
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H2OLOVA
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Re: ;-p

Post by H2OLOVA »

wopass wrote: i wouldnt remove too many tho as the pack strength stops your axle wrap.


and you need that when you fit the stonkin V8 into it aye Wopass :wink: :wink:
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Post by nzdncjw »

Got no plans in the imediate future for a v8..... Thanks for all the ideas! I'll get onto it next week - Think I'll take three out the rear and one maybe two out the front. See how she sits, I can always pu one back in! Off for a holiday in a couple a days for Easter so busy packing now! I'll keep yas posted with progress next week!

Chris
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Post by SMOKEY »

Hi all, earlier in this post the word Military wrap came up and then people are talking about cutting , :oops: .
The Military wrap on a laminated leaf spring is the extra wrap around the eye of the spring from the second leaf and must not be cut.
The wrap or Clip as it is called that you are cutting is designed to stop the leafs from fanning. These can be moddified (have a look at OME or other brand after market springs ) , to give less fricton and more opening up of the individual leafs.
Be very carefull when removing leaves, one leaf is eqivilent to 30% of the spring rate and it is very easy to over load the rest of the spring.
Removing leaves is also going to alter the braking and steering of the vehicle.
By all means have a play but my recommendation would be one leaf at a time and do lots of testing before your final set up.

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