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SUA Shackle Reversal Landcruiser
Posted: Mon Oct 11, 2010 10:32 am
by Ricko
Hey guys
I am looking to improve my suspension now that I am going to step up a class in competition. I am confident of working the rears better but am having trouble deciding on how to do the front. Also, at this stage I can't go to coils, if I can, I will.
So at the moment, in the front of my BJ42, it has 75series leaves and extended shackles and works well enough. When it gets locked, I won't need any more flex to be competitive. I want to do a shackle reversal to improve the approach as this is where we get in trouble the most, and I want to use the original front hangers, not dropped hangers, for the best approach. The problem is how to mount the shackles. Ideally the shackle should be mounted in the chassis to improve the castor as the rear of the leaves will be much lower than the front. However this will mean I will lose height, which is not ideal as it is only about 3" lifted now, and I don't want to go lower. Loopier leaves to compensate for height loss will probably mean less travel etc etc.
If anyone is getting the gist of my issues and have seen some good solutions and even have some photos, please let me know and post up. Basically, it has to stay SUA and can only be 4" lift max. After that, it's pretty open.
Thanks for any help and ideas.
Rick
Re: SUA Shackle Reversal Landcruiser
Posted: Mon Oct 11, 2010 12:32 pm
by Cyrel
Castor wedges should be able to comp for the angle of the leaves. Only draw back is the slight lowering of the spring packs in relation to the diff.
cheers
Re: SUA Shackle Reversal Landcruiser
Posted: Mon Oct 11, 2010 12:54 pm
by TWISTY
Could just mount the shackle hanger lower on the chassis, or even under it to keep as much height as possible, then do a cut'n'turn on the diff to return the castor angle.
Re: SUA Shackle Reversal Landcruiser
Posted: Mon Oct 11, 2010 1:20 pm
by De-lux
Wish I could weld and had a spare $250. I'd be getting this:
http://www.man-a-fre.com/parts_accessor ... s_fj40.htm" onclick="window.open(this.href);return false;
Re: SUA Shackle Reversal Landcruiser
Posted: Mon Oct 11, 2010 1:25 pm
by WICKED
Re: SUA Shackle Reversal Landcruiser
Posted: Mon Oct 11, 2010 5:18 pm
by Ricko
I've seen this, I don't like it because the front hangers are dropped and therfore reducing the approach. The main reason for the shackle reversal is to remove the shackles from hitting every freakin rock that seems to be in the way.
TWISTY wrote:Could just mount the shackle hanger lower on the chassis, or even under it to keep as much height as possible, then do a cut'n'turn on the diff to return the castor angle.
So you reckon the springs would still work even though they would be kinda pointing backwards, not straight up?? I really need to do a diagram...
Re: SUA Shackle Reversal Landcruiser
Posted: Tue Oct 12, 2010 6:26 pm
by Dannyboy
i did this to mine and ended up putting a drop bracket on the front then put it back to the shakles up front until i can do it properly. A cut and turn wont be enough the pinion angle is too great. when i do it again i will cut the perches off the diff and correct the caster that way. Im thinking of doing mine again with 60 springs and use the extended shakles i have. Also remember you will need to modyfy your front shaft for more slip as the wheel droops it moves toward the front of the car. I found with shakle reversal it was fine until applying sudden full throttle at full droop which must have made the spring wrap enough to make the shaft drop out.
Re: SUA Shackle Reversal Landcruiser
Posted: Tue Oct 12, 2010 10:13 pm
by Z()LTAN
I did a SR on mine SOA
No Dropped front hanger just cut and rotated spring perches and knuckles.
The leaves are on a pretty wikid angle but hasnt seemed to effect things. Still flexes well and has awesome high speed handling.
Re: SUA Shackle Reversal Landcruiser
Posted: Wed Oct 13, 2010 7:19 pm
by TheBigBoy
You dont need to weld anything. I fabbed my own shackle reversal on my 75 seires front. MAN WHAT A DIFFERENCE!! Your wheel wants to come backwards and up when you hit a bump instead of trying to push forward and up (crashing). It flexed ALOT better. Mine was simple, bolts through the bullbar chassi holes, and dropped down 50mm lower to the new reverse leaf point, with a cross peice of pipe between the 2. Then just get your shackles made, a big wedge (castor angle) with a new diff locator hole in it. Done. The only 1 problem is that it lengthens your wheel base.
Re: SUA Shackle Reversal Landcruiser
Posted: Thu Oct 14, 2010 3:39 pm
by shorty_f0rty
Rick have you checked out ih8mud for any feedback? I know a lot run SOA over there but there are some guys that keep it sprung under. I'm sure they would be able to give you some info on the mod. I was looking through the pics of a recent trip they did and nearly every rig (while SOA) had a shackle reversal.
Anyway.. why don't you just carve off your fixed shackle hanger, bolt/plug it up front and put a shackle through your chassis.
Re: SUA Shackle Reversal Landcruiser
Posted: Thu Oct 14, 2010 8:02 pm
by Ricko
Lengthened wheelbase is good, drive shaft lengths not a problem.
shorty_f0rty wrote:Rick have you checked out ih8mud for any feedback? I know a lot run SOA over there but there are some guys that keep it sprung under. I'm sure they would be able to give you some info on the mod. I was looking through the pics of a recent trip they did and nearly every rig (while SOA) had a shackle reversal.
Anyway.. why don't you just carve off your fixed shackle hanger, bolt/plug it up front and put a shackle through your chassis.
Yeah found a thread on ih8mud, was fairly negative towards SUA shackle reversal, but seemed to ignore approach angle issues. Since that is the only reason I want to do it, I've kinda ignored that advice.
I think in the end the solution will be as follows (with variation as required...)
Fixed front hanger at chassis height as per current shackle mount.
Rear shackle mount in chassis.
New shackles, maybe a fraction longer.
New custom springs, slighty longer in length and also "loopier" to regain height loss from through chassis mount.
Hopefully should only need wedges to get castor right, however if not, they're going on 60 diffs anyway, so get the cut and turn done at the same time as pumpkin mod if necessary. Hopefully buds can sort me out with that.
Or better yet, I get approval for coils.
Re: SUA Shackle Reversal Landcruiser
Posted: Thu Oct 14, 2010 8:16 pm
by shorty_f0rty
mmm coils ftw..
can you flip your front springs to improve your approach angle? just get bigger tyres
Re: SUA Shackle Reversal Landcruiser
Posted: Thu Oct 14, 2010 8:59 pm
by Ricko
shorty_f0rty wrote:mmm coils ftw..
can you flip your front springs to improve your approach angle? just get bigger tyres
The 75 springs position the diff in the middle, same as yours??? Custom springs will maximise approach as well.
Going to 35's, but that won't be enough. I have heard enough bad reports from Twisty to know that the shackles still hit with 35's. Since it is my current nemisis in comps, those shackles are gorneskis.
Mmmmm, coils.....
Re: SUA Shackle Reversal Landcruiser
Posted: Fri Oct 15, 2010 7:10 am
by hulsty
75 springs have a 2'' offset center pin, 60 series a ore o less centered.
Re: SUA Shackle Reversal Landcruiser
Posted: Sat Oct 16, 2010 5:51 am
by bj on roids
Dannyboy wrote:i did this to mine and ended up putting a drop bracket on the front then put it back to the shakles up front until i can do it properly. A cut and turn wont be enough the pinion angle is too great. when i do it again i will cut the perches off the diff and correct the caster that way. Im thinking of doing mine again with 60 springs and use the extended shakles i have. Also remember you will need to modyfy your front shaft for more slip as the wheel droops it moves toward the front of the car. I found with shakle reversal it was fine until applying sudden full throttle at full droop which must have made the spring wrap enough to make the shaft drop out.
A cut and turn wont be enough? (You can cut and turn the steering knuckles all the way around)
As for dropping the shaft out, you need a hilux solid axle long slip yoke.