Outer Limits 4x4 Board

11_evl wrote:the type that shares the load thru the centre bolts seem like a good idea

yup thats basicly the best way to do it.

i am still planing how to make mine. i am prob going to use some 32NB heavy (4mm) as the main pipe. prob use them hilux or similar (make my own from 5mm plate) on the axel. use spring bushes as the bushes and use a shackle at the body end.

basicly an effective and non restricting anti wrap bar needs to be able to have movement via a shackle? basicly what 31 zooker has made up.

shackle or a slip'n'twister. It needs forwards and backwards movement for the arc of leaf springs.

31zook wrote:shackle or a slip'n'twister. It needs forwards and backwards movement for the arc of leaf springs.

I believe the slip'n twist works better than the shackle set up

well I have both
Nik

31zook wrote:shackle or a slip'n'twister. It needs forwards and backwards movement for the arc of leaf springs.

wtf is a slip and twister?

so it need to be able to move back and forwards what about side to side?
is there a limit on how much the shackle can move forwards?

Well dont look at mine I wasnt thinking when I wrote that last post lol
A slip and twist has a sleeved pipe near the chassis mount that allows for any forwards and backwards movemnet as well as letting the diff articulate without binding.
I dont have a pic to upload atm but if there isnt 1 up when I get home from work.
Just realised jimbos already posted some, check them out and you,ll understand slip & twist.
Nik

just wondering how this prevents wrap when it allows the diff to move back and forth 75mm either side of centre?

don't you think that the shackle may invert and jam?

31zook wrote:shackle or a slip'n'twister. It needs forwards and backwards movement for the arc of leaf springs.

if you can work angles correctly then you may be able engineer a solution rather than just add bits on to bootyfab an apparent solution.

I have never seen anything like that on a race car, professional built vehicle or even a dodgy bob mud racer.....

and 11.evl I think yours ripped out of the housing cause it wasn't able to move in the same arc as the springs. if you did make it so it traveled in the same arc then you would be able to fab something out one peice of steel

Jock wrote:

just wondering how this prevents wrap when it allows the diff to move back and forth 75mm either side of centre?

don't you think that the shackle may invert and jam?

Jock have you ever built a wrap bar? We attached the overhead 5T crane and flexed it ever possible way, even a straight lift from the rear tow bar. Call it booty fab if you want but i spent 11hrs building it as tough as nails. Knowing what NIK drives, i made it to not fail. When you lift up the rear of the truck with only one bush bolted up ontop of the diff, The bottom of the bar moves over about 3mm. And how the funk is the bar meant to stop forwards and backwards movement? Thats what your leafs are for, Its only meant to stop Vertical twist.

Yes i guess on paper you can do a one link wrap bar but I would like to see it work without fail...

My 2c

im just thinking. that bar was made for a LWB. does anything change when going on a SWB other then the lengh?

brendan_h wrote:im just thinking. that bar was made for a LWB. does anything change when going on a SWB other then the lengh?

no works the same as lwb just different length

yeah -the angle is way steeper!

alien wrote:yeah -the angle is way steeper!

yer thats what i was thinking too. just asked to make sure it wasnt going to effect anything.

so have we come to a verdict what best way to make one?

31zook wrote:

Jock wrote:

just wondering how this prevents wrap when it allows the diff to move back and forth 75mm either side of centre?

don't you think that the shackle may invert and jam?

Jock have you ever built a wrap bar? We attached the overhead 5T crane and flexed it ever possible way, even a straight lift from the rear tow bar. Call it booty fab if you want but i spent 11hrs building it as tough as nails. Knowing what NIK drives, i made it to not fail. When you lift up the rear of the truck with only one bush bolted up ontop of the diff, The bottom of the bar moves over about 3mm. And how the funk is the bar meant to stop forwards and backwards movement? Thats what your leafs are for, Its only meant to stop Vertical twist.

Yes i guess on paper you can do a one link wrap bar but I would like to see it work without fail...

My 2c

Serously get over yourself its the internet. is it the only place you feel important.

Quite often driving in the bush I get the back of my car picked up in the air by a crane......

Think about this anti wrap is just that. It is designed to stop the diff twisting the springs. Anti wrap bar is a poor excuse for lightening springs so much that they can't take the torsional force of the driving system. Imagine the wheel can't turn cause it is jammed into a rut,rock, tree stump etc etc so it transfers all the turning force into the spring and bends it. It has nothing to do with suspension movement. static tests will do nothing.

Go outside and play and you will see.

PS yes I might have made one or two

PPS take it out and do all the same tests and see if it moves the same......

Ok so fair enough, i thought you were some skool kid who had read every book and mag under the sun but never done anything.
The crane comment was in relation with being belled out, i was checking how much the wrap bar was going to change the arc of the suspension cycle.

But im still confused as to how the shackle can invert or Jam?

I didn't mean to offend anyone

Im baffled by all this, Jock are you trying to say an anti wrap bar isnt needed if the springs arnt "lightened"?
I run ome hd packs with the main and 2nd leaves custom 3" longer. There is 7 leaves in the pack so they definately arnt lightend.
Your right this hasnt been field tested yet BUT Ive seen alot built with the shackle the same that work but we added a swivel joint at the bottom to allow for articulation.
And to the "bootyfab" comment all I can say is what was done on this 1st attempt at a wrap bar was far superior work compared to other well known companies that have done other work on my rig.
Nik

how would you make a slip and twist, to make a slip join seem you are going to need some pipe and tube. needs to be a nice fit though. what did you use and how much aprox is an acceptable amount of clearance each side?

here is a thread on the traction bars
http://www.pirate4x4.com/forum/showthre ... bar&page=3


what i am confused about is you want to stop the axel wraping. adding a shackle/slip join wouldnt it allow the axel to still wrap because it got the movement in the shackle ect?

for reference point on mounting it at the diff end. this pic was taken best to the center as i could.seems as though mount it isnt going to be in the center, prob have to offset it a little? i was think about 30-40mm to the right or having the center on the mount for the trac bar in the middle of the weld where the center is welded to the axel tube.the maybe puting a brace onto the center of the diff . also hand brake bracket is in the way.



sorry for my hijack but i am sure everyone is going to benifit from it

brendan_h wrote:how would you make a slip and twist, to make a slip join seem you are going to need some pipe and tube. needs to be a nice fit though. what did you use and how much aprox is an acceptable amount of clearance each side?

here is a thread on the traction bars
http://www.pirate4x4.com/forum/showthre ... bar&page=3


what i am confused about is you want to stop the axel wraping. adding a shackle/slip join wouldnt it allow the axel to still wrap because it got the movement in the shackle ect?

for reference point on mounting it at the diff end. this pic was taken best to the center as i could.seems as though mount it isnt going to be in the center, prob have to offset it a little? also hand brake bracket is in the way.



sorry for my hijack but i am sure everyone is going to benifit from it

thats why the slip 'n twist set up works better no shackle needed mount the chassie end with a bush and you can get seamless tubing I would drill holes and put a series of grease nipples down the tube and mounting it to one side would still be ok the slip'n twist is designed no to bind when flexing the axle but stops the up'n down twisting motion created bye toque

ive edited my post so might want to read that again. lol i keep thinking of ways to do it.

yer if i do a slip and twist i wont use a shackle. i will more then likely use a slip and twist. and yes i was thinking of some grease nipples too.

im just confused as to how it stops wrap if it got that slip in it as the axel is trying to wrap it will move back making the distance from the trac bar mounts further away?

brendan_h wrote:ive edited my post so might want to read that again. lol i keep thinking of ways to do it.

yer if i do a slip and twist i wont use a shackle. i will more then likely use a slip and twist. and yes i was thinking of some grease nipples too.

im just confused as to how it stops wrap if it got that slip in it as the axel is trying to wrap it will move back making the distance from the trac bar mounts further away?

thats the idea of the sip'n twist the axle can move back and fowowrd but the pinon wont twist up'n down its the up'n down movment of the pinion is what bends the leaf packs

Bly a slip and twist is a driveshaft slip joint. Probably could use a drive shaft too if it didn't have splines

brendan_h wrote:Bly a slip and twist is a driveshaft slip joint. Probably could use a drive shaft too if it didn't have splines

yeah most 4wd drive shafts have slip joints but dont twist

there's some good reading in here as will as some good pics

http://www.pirate4x4.com/forum/showthre ... slip+twist

one way to eliminate most of the axle wrap.........correct diff gears....

how will correct diff gears stop axle wrap? How does it work?
Nik

NIK wrote:how will correct diff gears stop axle wrap? How does it work?
Nik

yeah x2 please explain

manufacturers work out final drive ratios based on desired engine rpm etc to tyre size. when this is deviated from, e.g larger tyres on stock gearing the forces placed on the rear diff and components increases. basically the tyre becomes harder to rotate causing components such as leaf springs and bushes in controls arms to flex more and be placed under more stress. when tyre size is increased and diff ratios fitted to correct it the stresses are pretty much brought back to standard (working with the manufacturers specified weights).

joeblow wrote:manufacturers work out final drive ratios based on desired engine rpm etc to tyre size. when this is deviated from, e.g larger tyres on stock gearing the forces placed on the rear diff and components increases. basically the tyre becomes harder to rotate causing components such as leaf springs and bushes in controls arms to flex more and be placed under more stress. when tyre size is increased and diff ratios fitted to correct it the stresses are pretty much brought back to standard (working with the manufacturers specified weights).

thats 2 hard for the average bloke to work out

jimbo jones wrote: thats 2 hard for the average bloke to work out

hence why there are so many spring, tailshaft, t/case mount and rear end problems.

plenty of sites have ratio calculators.

joeblow wrote:manufacturers work out final drive ratios based on desired engine rpm etc to tyre size. when this is deviated from, e.g larger tyres on stock gearing the forces placed on the rear diff and components increases. basically the tyre becomes harder to rotate causing components such as leaf springs and bushes in controls arms to flex more and be placed under more stress. when tyre size is increased and diff ratios fitted to correct it the stresses are pretty much brought back to standard (working with the manufacturers specified weights).

I admire your work joe, but I can't agree with you here. I agree that increasing tyre size does increase the required wheel torque to produce the same forward force. However the torque on the axle housing is always equal in magnitude to the torque at the wheels, just in the reverse direction.

To put it another way, it does not matter how small you make the pinion, the force it has to apply downwards on the ring gear, hence the reactionary force it applies upward on the carrier is the always the same for a given wheel torque. All that changes is the required input torque at the pinion. (this will change the side to side torque ie the reactionary force that tries to lift the right wheel off the ground and push the left into the ground due to the rotation of the tail shaft, but this force is minimal and is not what bends our springs)

I'm willing to be corrected if I have missed something.