Shackle Reversal & SOA

[El_Diablo]

Hey guys, ive got my SOA kit here and i was wondering, why not do a shackle reversal at the same time?

Now the big question... what should i do about mounting the perches to get the proper caster/pinion angle? Any idea on how many degrees i should rotate the perches down towards the rear?

Am i over thinking this and should i just keep the pads in a stock orientation or would this be a good opportunity to adjust things correctly for the shackle reversal?

[Casey]

Hey guys, ive got my SOA kit here and i was wondering, why not do a shackle reversal at the same time?

Now the big question... what should i do about mounting the perches to get the proper caster/pinion angle? Any idea on how many degrees i should rotate the perches down towards the rear?

Am i over thinking this and should i just keep the pads in a stock orientation or would this be a good opportunity to adjust things correctly for the shackle reversal?
IIRC I rotated mine up a couple of degrees, no more than 4. I set it up in the driveway and temporarily installed the u-bolts/perches, then checked the angle of the t-c yoke and tacked the perches at that angle. Worked great and there was no vibration at speed.

I sold those a while back or I would check the angle for ya.

[El_Diablo]

was that with a shackle reversal? basically im looking to keep the caster angle stock... anyone know what it is?

would it be wise to flip the springs while im at it to get some added wheelbase? i would imagine that would also help with clearance issues of doing a rear shackle aswell?

[Casey]

was that with a shackle reversal? basically im looking to keep the caster angle stock... anyone know what it is?

would it be wise to flip the springs while im at it to get some added wheelbase? i would imagine that would also help with clearance issues of doing a rear shackle aswell?
ummm...my bad. :o

I didn't read 'reversal' I was talking about the rear axle.

[Casey]

However, changing the front perches isn't so easy. The way to do it right is to cut and turn to keep the caster correct.

I'd start by making the reversal work with the stock perch angle.

[El_Diablo]

i going SOA though so it would be easier to rotate the perches to keep the stock cast rather than rotating the knuckles, all im after really is to keep a stock caster angle which should be achievable by rotating the perches unless im thinking incorrectly?

[Casey]

I see where you're going with it, but your math better be spot on.

I had a ScoutII back in the 80s when SOA wasn't as popular or seen. After we did the driveway custom SOA the thing wouldn't go in a straight line. I had them cut and turned. There was little change and it was screwed.



I've no experience with FSJ shackle reversal. Seems to me lowering the front hanger would be the way to correct for the caster angle.

[El_Diablo]

all you're really doing is correcting the new slope of the springs, according to one of the threads on here its approximately an 8 degree change in slope of the springs so if i move the spring pads 8 degrees downward, i should make up for the effects on the pinion and caster while keeping the stock ride height which would be changed if you extended the front shackle mount

the only problem is getting accurate measurements, not to sure what i should do for that....

[AlsChopShop]

i would just set up your shackle reversal first. then like casey mentioned, you can bolt up the axle and find your stock angle, then tack the perches into place.

Al

[rocklaurence]

I recently did a SR with the OEM mounts and it did create 8 degrees positive caster and moved the axle forward 1". I measured my axle rotation at the Differential cover (flat surface of 2 cover bolts) and then corrected the caster by installing wedges (6degree).

[Cappicaper]

I just went through this on my Gladiator. I was going to set caster @ 4 until I got off the phone with partsmike (for some high steer arms). His contention was that I should be in the 5-6 range in order to have the tires steer more easily on the road (36" tires). I also checked the factory settings on the Chevy axle I swapped in and it listed 8 as factory setting - I think this was to accommodate for the full time drive flanges that year came with.

Do the reversal, set the perches on the axle and measure the degrees on the top of the driver's side knuckle before the steer arm is on there. They are machined 90 degrees to knuckle. Bear in mind that the springs have to have the weight of the truck on them to get the proper reading.

I dropped the truck on them, measure my angle, needed to adjust 2 degrees, raised the truck back up, loosened the axle and turned it 2 degrees, retightened everything and dropped it back down. Took my measurement again and hit it. I then tacked them, took it all apart and welded it out.

The fun part is centering the axle under the frame ;)

[dank idea]

On my SOA i also reversed my front springs , i kept the perch angle same as stock and have no issues.

[El_Diablo]

ok, so heres the plan, i will take the axle and springs completely out, install the springs with the short end towards the front to further move the axle forward and install the factory shackles in the rear

once that is done i will grind the pumpkin round so that i can fit the perch anywhere that i need to, i will then place the axle under the jeep, line the perches up width wise to the factory position and loosely fit the u bolts to the axle

with that done i'll lower the weight of the jeep on to the axle (supported by jack stands) and check for the caster angle of 6 degrees, i will then adjust as necessary and tack weld the perches on



im thinking with the flipped springs and SOA i shouldn't have the driveshaft problems that most have but we shall see... hoping an XJ shaft will have enough slip to make this work

this combination should also help with steering clearance for the temporary drop pitman setup




any thoughts on these plans?

[dank idea]

I like the way you think... That is perfect for the XJ drive line. That is what i used in mine and have had no trouble.

[El_Diablo]

anyone see any flaws in my plans? any ideas thoughts or opinions? tips or tricks?

[XtremeOverKill]

I'm not one to judge in on this, but defintly subscribed!

Interested to see how this comes out as I'd be interested in doing something simliar if you find success.

Best of luck

[El_Diablo]

my biggest issue right now is trying to find a driveshaft, i grabbed a 5spd 6 cylinder xj driveshaft but i dont think its going to have enough slip so im currently trying to find a 32 spline PTO slip joint

[cocurtiss]

square tube!

[El_Diablo]

with a full time case? that gets used during winter driving at speeds up to 70-75mph? dont think it'll work to well.....

[rustywagoneers_com]

The longest 'stock' slip setup that I have found is old solid-axle toyotas.

You can make life easy - but take a big chance - by buying toyota flange yokes for your axle and t-case.

Or, if you are very careful and up to the challenge, build yourself a shaft with 1310 at the axle (like stock) and the FSJ 1310 CV at the t-case (again, stock) but using the toyota slip section.

[AlsChopShop]

owith that done i'll lower the weight of the jeep on to the axle (supported by jack stands) and check for the caster angle of 6 degrees, i will then adjust as necessary and tack weld the perches onyour problem will be once it leaves the jack stands! it needs to be on all four tires, on level ground before you measure your caster. if the axle is up on jack stands, you will get an incorrect angle reading.

Al

[El_Diablo]

there are two options, i can hack 2 shafts into one or i can use splines and a coupler from another source and splice them into the xj shaft i have

i may also try a square driveshaft but if anything it will most likely end up as a backup, most likely i'll try the PTO style square shaft which is encased by a more traditional round slip housing



Al, my plan is to use a low set of jack stands that i have to mimic ride height with my 32's so the weight should be right around the normal driving position, im not to worried about it as if it makes a difference it should be minimal

[ClovisMan]

there are two options, i can hack 2 shafts into one or i can use splines and a coupler from another source and splice them into the xj shaft i have

i may also try a square driveshaft but if anything it will most likely end up as a backup, most likely i'll try the PTO style square shaft which is encased by a more traditional round slip housing



Al, my plan is to use a low set of jack stands that i have to mimic ride height with my 32's so the weight should be right around the normal driving position, im not to worried about it as if it makes a difference it should be minimalIf you end up not using the XJ driveshaft, I'll trade you straight up for that driver's side flattop knuckle I have for sale. I'm doing a traditional SOA/SF and the xj shaft should work fine for me. Let me know.

[El_Diablo]

consider it done, just PM me your address