Castor Correction - swivels or radius arms

[LROV90]

Hi,

Having now lifted my 90 about 3 inches I need to correct my castor, thats now sitting at about -1 deg. I have already fitted both front and rear d/c shafts to get rid of most of the vibrations. I don't wont to really move the pinion angle from where it is now as it suits the d/c shaft fine - making corrected swivels the best bet. However the front springs and shocks are sitting on a fair angle as the diff has rotated foward so I wouldn't mind correcting this also - making radius arms the go!

Suggestions??

[langy]

Various places in the UK ( Buy a UK LR mag to find out) sell castor correction bushes for lifts up to 2.5 inches.
Next stage is a new set of cranked and lighted radius arms. Finally, Disco White has successfully machined a set of swivel balls.

How much you got to spend?

[Slunnie]

I guess the answer lies in how you want to deal with your propshaft angles and remaining vibration free. I would have thought swivels and then run a DC front shaft.

[modman]

bend the radius arms as well. its free. you can even do them cold.
cranked radius arms (2 bends in each arm) allow the bush at the chassis end to sit neutral and can help with caster. however i would still get caster checked and adjusted as necessary.
its funny seeing people drive radius arm equiped vehicles around lifted to the max, you can see the chassis end bush has no down travel left:wacko: :wacko:
david

[Ken]

Dont Equipe 4x4 do the Adjusted Radius Arms ? there here in Aus

[JEEPEYTR]

bend the radius arms as well. its free. you can even do them cold.
cranked radius arms (2 bends in each arm) allow the bush at the chassis end to sit neutral and can help with caster. however i would still get caster checked and adjusted as necessary.
its funny seeing people drive radius arm equiped vehicles around lifted to the max, you can see the chassis end bush has no down travel left:wacko: :wacko:
david

Wouldn't this end up shortening the radius arms considerably, thereby drawing the axle rearward and shortening the wheelbase, pulling the spring seats out of alignment, etc. even more than lifting has already done? The companies I have seen that offer castor corrected radius arms in the US also lengthen them, correcting the axle position for lift as well, thereby maintaining the axle position.

[HSVRangie]

No I have cranked arms on my RR.

they shrunk about 1-2 mm.

Fit 2m washer and all is good.

Michael.

[LROV90]

So how do I go about bending my radius arms? Hydraulic press??

[lokka]

Yep id like to know as well how dose one crank the raidus arms and were sum pics would be nice too please:D:D:D:D

[HSVRangie]

So how do I go about bending my radius arms? Hydraulic press??

I had access to a forge.

daddy a black smith :):)

can be done cold to.

Michael.

[lokka]

I had access to a forge.

daddy a black smith :):)

can be done cold to.

Michael.


Ok how much of a kick did ya put in em and were did ya kick em as ive got oxy i can heat em and bend em easy enuf just need to know were and how far as il prolly make a jig to do this so both are the same and then i can do some others as well for a few mates and my bro will prolly want sum when he sees mine

Cheers

Chris

[HSVRangie]

draw the arm on bench (trace around.)

Draw in top 75mm higher.( chassy mount)

bend to suit.

end result is castor correct.

neutral arm location in chasy bush.

http://img.photobucket.com/albums/v607/HSVRangie/Frontradiasarm.jpg

Michael.

[lokka]

Sounds too easy il have to give it a go thanks for the pic :D:D:D

[Ralph]

Les Richmond Automotive do a correction at the swivel hub which seems a lot more sensible.
http://www.lrautomotive.com.au/100.html

Arn't there legal issues with heating and bending certain components?

[HSVRangie]

yep but I tyhink you wil find indexing swivell housing to have same issues, just not as easy to find.

MIchael.

[discowhite]

I have already fitted both front and rear d/c shafts to get rid of most of the vibrations

you must have some serious vibration issues to go to all that trouble!
im running 150mm bumpstop clearance f&R, still have the std td5 front drive shaft and have lengthened another front for the rear, all with big chunky MT117sports. 140kph and still no vibes at all.

ide go the slotted swivells, i now have anywhere between -1deg to +12deg.

cheers phil

[discowhite]

bit hard to see but there isnt much angle on my front bushes.
http://inlinethumb08.webshots.com/4615/2412236690100509853S425x425Q85.jpg

cheers phil

[LROV90]

you must have some serious vibration issues to go to all that trouble!
im running 150mm bumpstop clearance f&R, still have the std td5 front drive shaft and have lengthened another front for the rear, all with big chunky MT117sports. 140kph and still no vibes at all.



It all depends on what vibs you are trying to get rid off!! I didnt have any noticable vibs running JT2's either but when you have normal m/t's on you notice the driveshafts - especially the front one!! My front radius bushes are about the same as yours - what sort of angle is the bottom mount for the front shock on??

[Blknight.aus]

No I have cranked arms on my RR.

they shrunk about 1-2 mm.

Fit 2m washer and all is good.

Michael.

^thats how id do it on the cheap.

[Slunnie]

At 2m I would have called the washer something more like heavy wall pipe.

[Blknight.aus]

thats the diameter of it not the thickness, you put it underneath between the axles and use it as an all in one skid plate and side steps.

as a bonus a 2m diameter washer has a big enough hole in the middle that you can still get to the tcase and gearbox drain/fill plugs

[rangieman]

Has,nt what HSV done only alter the angle of the bush,s and not the carstor angle:cool:

[Blknight.aus]

Has,nt what HSV done only alter the angle of the bush,s and not the carstor angle:cool:

you being serious or just taking the mick?

if your being serious, yes it will change the castor angle. It also changes the wheelbase.

[rangieman]

you being serious or just taking the mick?

if your being serious, yes it will change the castor angle. It also changes the wheelbase.
I should have explained it better it will not return the castor to standard specks
if you wanted standard castor specks the radius arms would have to be longer
When you lift suspension in the front your front diff is forced forwards at the top of the diff which tilts the bottom of you diff backwards hence throwing your castor out :cool:

[Blknight.aus]

umm if you crank bend the arms the axle housing will be back at the same angle as it was, castor angle problem caused by suspension lift solved..

now the axle will be closer to rear of the vehicle
add some washers to infront of the locating bush on the chassis

solved...


If you only put a single bend in or a long bend by pressing the center of the arm downwards then you get some interesting hassles.

[Bush65]

With a decent amount of suspension lift, correcting the castor by means other than rotating the swivel, will usually cause driveshaft vibration (remember the front uni-joints are not equal angles on coil sprung rovers).

Cranking the radius arms (to correct pinion angle) combined with rotating the swivels (to correct castor) is the best combination. A double cardin driveshaft is best to eliminate driveshaft vibration and then it is more important to correct castor by rotating the swivels.

[Blknight.aus]

urmmmmmm

if you bend the radius arms (locating arms, hockey sticks, bloody big things I always hit my headon when sliding out from under a rover on a trolly) so that the castor angle is correct the pinion should be at the same angle as it was before... unless you have some wierdo ifs/live beam combo front axle.

The problem comes when your lift takes the Ujs past their optimal working angle which is when you need to think about getting yourself a CV setup drive shaft (exxy but nice) or a double cardan setup.

This allows you to mess with your shafts icomplimentary angles a fair bit more.

[Defender200Tdi]

As I understand it, there are two bends usually made in the radius arm, making it into a kind of stretched Z shape. One bend to correct the bush alignment at the chassis end, and the other to correct the castor. The second bend is the one that tips the diff nose back down correcting castor, but putting the strain on the uni joints.

I wonder of doing the first bend to get the bush alignment back, but not doing the second bend to correct castor, thus leaving the diff nose pointed up at the transfer box, would alleviate some of the chances of the uni joints complaining? Rotating the swivels could then fix the castor.

Getting the length back in the radius arms seems to be the tricky bit. Adding washers on the front bush can only go so far before the bushes are over compressed, and you'll only evr get half of the thickness of the washers you add after both bushes compress and equalise. I suppose if the arm comes out only 1mm shorter, then a 2mm washer should do it.

Paul:)

[tombraider]

No I have cranked arms on my RR.

they shrunk about 1-2 mm.

Fit 2m washer and all is good.

Michael.

It works!

But just to be the legal guy on this one... It isnt legal. :angel:

But it does work!

[100I]

I wonder of doing the first bend to get the bush alignment back, but not doing the second bend to correct castor, thus leaving the diff nose pointed up at the transfer box, would alleviate some of the chances of the uni joints complaining? Rotating the swivels could then fix the castor.


To avoid vibration the diff pinion & the Xfer case output shaft need to be as close as possible to parallel, within a tolerance of 3deg comes to mind.

[JEEPEYTR]

No I have cranked arms on my RR.

they shrunk about 1-2 mm.

Fit 2m washer and all is good.

Michael.

Okay, I hate to sound like the idiot from the States here, but.. We lift a truck, lets say 3”. This forces the axle down away from the frame. Since the radius arms that are locating the axle haven’t changed, pushing the axle down rotates it forward as well (Rear pinion rotated upward). I’m sure we all agree on this, correct? At the same time, we have pulled the axle’s position rearward slightly, just as a matter of geometry, since the axle articulates downward in an arc (think Isosceles triangle here).

I hated algebra, but A squared plus B squared equals C squared, where ”A” is the distance from the radius arm mount on the frame to the point on along the frame where the center point of the lower spring seat is directly below it, “B” is the distance from this imaginary line directly down to the spring seat, and “C” is the distance from the radius arm mount on the frame to the axle along the radius arm’s path. Still making sense?

If we use the number 48” (rough guess of the actual distance) for “A” and 14” for “B” to represent stock (approximately the distance between the spring seats with a stock spring), this calculation gives us 50” for leg “C”, or the distance from radius arm mount to axle center, along the line created by the radius arm itself.

If we kick the numbers around a little, continuing to use 50” for “C” and using 17” for “B” (representing 3” lift), we can solve for the distance “A” which comes out to 47.02”. This suggests simply lifting 3” without changing anything else moves the axle back almost a full inch (not to mention that lifting the rear has drawn the rear axle forward in a similar matter, since it also articulates in an arc). Looks like we are now all series coiler drivers with 88” wheelbases, LOL!

But back to the radius arms. If we bend a standard length of metal that is relatively straight and 50” in length, its overall length is going to become less, which would suggest pulling the axle even further rearward. I guess after all this my question to HSV is, 2 mm seems hard to believe to me, given the considerable nature of the bends. I would think more like 2-3 cm or about an inch would be more likely, was this measurement actually taken “on the bench” before and after the arms where bent? Cause if this is the case, than the proof is in the numbers, and my head hurts for nothing.. Sorry about all the non metric measurements, by the way.

So are all of our lifted 90’s now shorter wheelbased than a Series? I probably just got banned for this long winded reply too, didn’t I?

[D110V8D]

So are all of our lifted 90’s now shorter wheelbased than a Series? I probably just got banned for this long winded reply too, didn’t I?

--------------------------
~Scott T.
'95 NAS D-90 ST (JEEPETR)
"If you're not living on the edge, you're taking up too much space!"
http://www.putfile.com/lrnad90


Maybe....but 88" is a good thing in my book.:cool:

[lokka]

As I understand it, there are two bends usually made in the radius arm, making it into a kind of stretched Z shape. One bend to correct the bush alignment at the chassis end, and the other to correct the castor. The second bend is the one that tips the diff nose back down correcting castor, but putting the strain on the uni joints.

I wonder of doing the first bend to get the bush alignment back, but not doing the second bend to correct castor, thus leaving the diff nose pointed up at the transfer box, would alleviate some of the chances of the uni joints complaining? Rotating the swivels could then fix the castor.

Getting the length back in the radius arms seems to be the tricky bit. Adding washers on the front bush can only go so far before the bushes are over compressed, and you'll only evr get half of the thickness of the washers you add after both bushes compress and equalise. I suppose if the arm comes out only 1mm shorter, then a 2mm washer should do it.

Paul:)

Paul thats the best idea ive herd so far ant some time tomorw il mark it out on a flat plate and play with sum numbers as like jeepeytr said wilt the geometry of it it dont sound rite with the lengths so the only way to do it and to get the answers is to lay it out and see what i come up with il have a go and il take sum pics and get back to you guys over the weekend some time

Cheers

Chris

[HSVRangie]

Okay, I hate to sound like the idiot from the States here, but.. We lift a truck, lets say 3”. This forces the axle down away from the frame. Since the radius arms that are locating the axle haven’t changed, pushing the axle down rotates it forward as well (Rear pinion rotated upward). I’m sure we all agree on this, correct? At the same time, we have pulled the axle’s position rearward slightly, just as a matter of geometry, since the axle articulates downward in an arc (think Isosceles triangle here).

I hated algebra, but A squared plus B squared equals C squared, where ”A” is the distance from the radius arm mount on the frame to the point on along the frame where the center point of the lower spring seat is directly below it, “B” is the distance from this imaginary line directly down to the spring seat, and “C” is the distance from the radius arm mount on the frame to the axle along the radius arm’s path. Still making sense?

If we use the number 48” (rough guess of the actual distance) for “A” and 14” for “B” to represent stock (approximately the distance between the spring seats with a stock spring), this calculation gives us 50” for leg “C”, or the distance from radius arm mount to axle center, along the line created by the radius arm itself.

If we kick the numbers around a little, continuing to use 50” for “C” and using 17” for “B” (representing 3” lift), we can solve for the distance “A” which comes out to 47.02”. This suggests simply lifting 3” without changing anything else moves the axle back almost a full inch (not to mention that lifting the rear has drawn the rear axle forward in a similar matter, since it also articulates in an arc). Looks like we are now all series coiler drivers with 88” wheelbases, LOL!

But back to the radius arms. If we bend a standard length of metal that is relatively straight and 50” in length, its overall length is going to become less, which would suggest pulling the axle even further rearward. I guess after all this my question to HSV is, 2 mm seems hard to believe to me, given the considerable nature of the bends. I would think more like 2-3 cm or about an inch would be more likely, was this measurement actually taken “on the bench” before and after the arms where bent? Cause if this is the case, than the proof is in the numbers, and my head hurts for nothing.. Sorry about all the non metric measurements, by the way.

So are all of our lifted 90’s now shorter wheelbased than a Series? I probably just got banned for this long winded reply too, didn’t I?

--------------------------
~Scott T.
'95 NAS D-90 ST (JEEPETR)
'96 Disco SD 5-speed (sold)
"If you're not living on the edge, you're taking up too much space!"
http://www.putfile.com/lrnad90


I thought similar prior to doing this.

But when I lay the modded arm next to Std arm they are no different in lth 1-2 mm only.

this is caused by the arm stretching at the bend more so than shrinking. It works when done hot.

Michael.

[HSVRangie]

Paul thats the best idea ive herd so far ant some time tomorw il mark it out on a flat plate and play with sum numbers as like jeepeytr said wilt the geometry of it it dont sound rite with the lengths so the only way to do it and to get the answers is to lay it out and see what i come up with il have a go and il take sum pics and get back to you guys over the weekend some time

Cheers

Chris


This is a good option but you will need a double cardan joint.
http://img.photobucket.com/albums/v607/HSVRangie/StdDriveshaftjpeg.jpg

https://www.aulro.com/afvb/

Regards
Michael.

[HSVRangie]

The best option is to crank arm at chassy end to realign the arm to bush.

Crank arm if required at diff end to align pinion correctly to out put on T/case.

Then fit double cardan shaft

Then rotate swivels to correct castor.

Michael.

[100I]

I believe it is this plane that the included angle is critical.
2259

A double cardan joint is basically 2 universal joints coupled in close proximity.
A constant velocity joint is different again.

[Defender200Tdi]

To avoid vibration the diff pinion & the Xfer case output shaft need to be as close as possible to parallel, within a tolerance of 3deg comes to mind.


Yes, I agree. But I suspect on the standard setup for a Landrover, they aren't even parallel to start with. Wasn't this the reason Landrover came up with the out of phase bodge for the uni joints at the front? In any case, lifting the suspension probably just makes a dodgey arrangement even worse.

Paul:)

[100I]

Yep your spot on. That's all I was pointing out, is that by not putting in the second bend it would be encouraging the vibration issue. They are on their limit from bog standard and any further modifications will only exacerbate that.
Of course there are trade offs to any design.
Whenever I stop throwing coin at my house [insert exasperated sigh] I plan to get serious with the LR. However the Disco being such a "nice car" to drive I want to make sure I don't accidently go overkill and make it a pig to drive to and from interesting places. Have made some poor engineering descisions in the past with cars/bikes and learnt my lesson.:D
Of course a dedicated weekend warrior is going to have different priorities too, so what's acceptable nuances to one person will drive another bat crazy.

[Bigbjorn]

Arn't there legal issues with heating and bending certain components?

Yes, indeed. Quoted verbatim from Qld. Transport " The welding, chrome plating, heating or bending of axles, suspension and steering components, as a method of repair or alteration, is not permitted".

Such an alteration or repair technically renders the vehicle unroadworthy.

Think of unscrupulous insurers who love to find an excuse to reject a claim, or slick lawyers apportioning blame in a damages case. "Dangerous, unroadworthy, illegally modified vehicle, irresponsible 4WD hoon". "Your Honour, we ask substantial damages and a period of imprisonment".

[Blknight.aus]

Yep your spot on. That's all I was pointing out, is that by not putting in the second bend it would be encouraging the vibration issue. They are on their limit from bog standard and any further modifications will only exacerbate that.

they aint on the limits but they are near the optimal angles..

ujs will drive though a bigger angle than a CV buuut...

1. as ujs get more bent their efficiency goes down, Cv's not quite so much
2. as Ujs get more bent they introduce driveline speed oscilations, cvs dont
3. as Ujs get more bent the wear quicker, cvs not quite to so much
4. Ujs are cheap, Cvs aint
5. Ujs dont mind water and dust Cvs DO
6. Changing a pair of ujs is an hours work on a good day.. CVs.....

From memory the maximum nominal angle for a Uj is about 30 degrees
lets say a CV can go to 40

when the cv hits 40 degress that it any more and your risking snapping it they uj might go onto say 50 degrees (to pick numbers that sound about right) but as you go past 30 degrees your increasing wear and increasing power loss through the joint..

If you get real lucky you might be able to trick the nominal driveline oscilations out of your shaft by offsetting the propshaft slip joint so the yokes are out of phase with each other, but good luck on that front.

[100I]

Yes, I agree. But I suspect on the standard setup for a Landrover, they aren't even parallel to start with. Wasn't this the reason Landrover came up with the out of phase bodge for the uni joints at the front? In any case, lifting the suspension probably just makes a dodgey arrangement even worse.

Paul:)


they aint on the limits but they are near the optimal angles..

ujs will drive though a bigger angle than a CV buuut...

.
Sorry that wasn't quite worded clearly. What I meant is wot you said. ;)
I meant that LR prop shafts are right on the edge of giving vibration problems, ah la setting the joints out of phase as Defender200Tdi had said. Yes, anybody who's played with IFS trying to get more travel has very quickly found the limits of the range of movement of their CVs for sure.

[discowhite]

what sort of angle is the bottom mount for the front shock on??

this is another ''to do '' job, once ive finalised my spring heights and rates..

https://www.aulro.com/afvb/images/imported/2007/05/438.jpg

cheers phil

[Bigbjorn]

At the White Motor Corporation plant in Brisbane,we went to a lot of trouble using a level slab, protractor sets, engineers levels, plumb bobs, centres, measuring tapes, wedges, shims to ensure that trucks had equal angle driveshafts, tandem drives square to the chassis, and to the front axle, and equal overall and internal wheelbases each side. A truck could not leave the plant until this was done and measurements recorded on the vehicle build sheet. Try doing this on your LR and be rewarded by improvements in driveline life, performance, and lack of vibration.

[LROV90]

this is another ''to do '' job, once ive finalised my spring heights and rates..

http://inlinethumb24.webshots.com/3863/2495844940100509853S500x500Q85.jpg

cheers phil

Looks about the same as mine! Suppose I will have to cut an reweld the bottom spring mounting plate!

[Slunnie]

Yes, indeed. Quoted verbatim from Qld. Transport " The welding, chrome plating, heating or bending of axles, suspension and steering components, as a method of repair or alteration, is not permitted".

Such an alteration or repair technically renders the vehicle unroadworthy.

Think of unscrupulous insurers who love to find an excuse to reject a claim, or slick lawyers apportioning blame in a damages case. "Dangerous, unroadworthy, illegally modified vehicle, irresponsible 4WD hoon". "Your Honour, we ask substantial damages and a period of imprisonment".
Exactly. Its probably a better method to lift, change the front propshaft over to a DC shaft with the DC at the transfer to sort the vibrations and use slotted steering balls to correct the caster.

[Slunnie]

1. as ujs get more bent their efficiency goes down, Cv's not quite so much
2. as Ujs get more bent they introduce driveline speed oscilations, cvs dont
3. as Ujs get more bent the wear quicker, cvs not quite to so much
4. Ujs are cheap, Cvs aint
5. Ujs dont mind water and dust Cvs DO
6. Changing a pair of ujs is an hours work on a good day.. CVs.....

Also the more angle you put into a CV, the weaker it becomes.

[Slunnie]

I believe it is this plane that the included angle is critical.
http://img.photobucket.com/albums/v607/HSVRangie/doubleCardanJointAnglejpeg.jpg

A double cardan joint is basically 2 universal joints coupled in close proximity.
A constant velocity joint is different again.
The Yanks call a Double Cardin joint a CV joint, and they seem to call CV joint Birfs or something.

I also understand its good practice to not run unis at 0 degrees but just slightly off this to keep the bearings in them moving and prevent pitting.

[DirtyDawg]

Hi,

Having now lifted my 90 about 3 inches I need to correct my castor, thats now sitting at about -1 deg. I have already fitted both front and rear d/c shafts to get rid of most of the vibrations. I don't wont to really move the pinion angle from where it is now as it suits the d/c shaft fine - making corrected swivels the best bet. However the front springs and shocks are sitting on a fair angle as the diff has rotated foward so I wouldn't mind correcting this also - making radius arms the go!

Suggestions??
Wot the D/C shafts cost ya and where did you get em..TIA

[JEEPEYTR]

The Yanks call a Double Cardin joint a CV joint, and they seem to call CV joint Birfs or something.

I also understand its good practice to not run unis at 0 degrees but just slightly off this to keep the bearings in them moving and prevent pitting.

If you end up angling the pinion that high to get the "0 degree" angle, make sure you compensate with added oil level in the diff, otherwise you could end up with pinion bearings that aren't getting lubricated anymore. One easy way to "overfill" the diff is to park the truck on a significant hill and top off (piinted down hill for the rear diff, uphill for the front, obviously).

P.S. -- A lot of guys do this with the T-Case as well to provide better oiling to the failure prone input gear, mainshaft spline wear area.

[LROV90]

Wot the D/C shafts cost ya and where did you get em..TIA


Think they ended up being about 1200 for both. I had them custom made using my original slip yokes. I needed a D2 front tranfer case output flange on the front and had to lathe up an adapter for the rear. Both D/C joints are spicer units the same model as the Jeep guys use. Managed to do the front one on my brothers 110 a whole lot cheaper but just using a D2 front shaft which is the same length and bolting it straight on - probably all you need for a 110!

[Slunnie]

For that cost you can order them from Tom Woods in the US and landed in Aus. He will also produce them with all new parts, the 1310 bigger unis and make the adaptors for the front and rear and include all of the hardware for the adapters. The yolk bits are stronger also being forged. You also wont have to buy the D2 front output flange. They take 1 day to manufacture and dispatch and will turn up at your door in a about 3-4 working days. The shafts are all made to order.
http://4xshaft.com/Landrover.html

[Defender200Tdi]

I paid $280 for a DII double cardan propshaft last weekend from Triumph Rover Spares in Adelaide. The only extra is a DII transfer box flange & new seal and the job's done.

Paul:)