Outer Limits 4x4 Board

I am in the middle of an SAS using a 60 series front axle.

I have the castor angle where I reckon it should be but it gives me a nasty camber inward at the bottom of the wheel.

Can the camber or king ping inclination be adjusted, or is it just a product of where you set the castor angle?

Also will increasing castor give me the problem I have or does decreasing castor cause it?

Any advice would be good as I am stuck until I sort this.

Cheers

what castor you running?


Has the knuckle drooped down when you rotated it?



Was the diff bent originally maby?

Im assuming u realise that the more angle u face ur pinion upward without doing a cut and turn makes your truck steer like a grader.

Im led to believe u can get some oval offset taper bearings to sit in the ball end of the axle housing which when turned to where u want it to will give pos or neg camber.
Im trying to rack my brain as to where i saw these if i remember i will get back to you.

Im sorry, are you doing a Cut and turn?

I,m running 3 degrees, even though the manual says 0.5 degree +-1degree for FJ62 and JH60L (R0)G

or

1 degree +- 1 degree for FJ62 and HJ60L (R)V

Maybe it does need to come back to 1 dgree?

The engineer requested 4 degrees but I told him I will try 3 even though the manual says 1.

Cheers

how are you achieving your castor angle?

Wozza244 wrote:Im assuming u realise that the more angle u face ur pinion upward without doing a cut and turn makes your truck steer like a grader.

Im led to believe u can get some oval offset taper bearings to sit in the ball end of the axle housing which when turned to where u want it to will give pos or neg camber.
Im trying to rack my brain as to where i saw these if i remember i will get back to you.

I would have thought castor defines camber, am I missing something important?

I do realise the more you rotate castor in either direction the worse it will behave either heavy if you give too much or flighty if too little.

Based on your grader example, will angling upward/increasing castor give the problem I have (camber in at the bottom)>

here's a pic of what it is like anyway,

Z()LTAN wrote:Im sorry, are you doing a Cut and turn?

No simply trying to set the castor corectly.

Z()LTAN wrote:how are you achieving your castor angle?

Short of machining a special tool to pass through the bearings I am using a level with a protractor square across the top of the upper bearing race in the knuckle, and rotating the diff backwards to acheive castor.

cheers

yep thats the way

make sure you pinion angle is still ok.

i think youll find that with the weight of the car on the hubs they will become more straight.

Mine are a bit cambered to, but its of no consequence..

Z()LTAN wrote:yep thats the way

make sure you pinion angle is still ok.

i think youll find that with the weight of the car on the hubs they will become more straight.

Mine are a bit cambered to, but its of no consequence..

Just to me what I have in the picture looks like too much?

I just jacked up the diff to increase cator and it seems to have increased camber in at the bottom too. So maybe 3 degrees is too much.

Will try 1 degree tomorrow.

Pinion angle should be ok it has a double cardan on the fornt shaft.

Cheers

i run 5 deg

Mine has a bit of camber... not that im worried

Z()LTAN wrote:i run 5 deg

Mine has a bit of camber... not that im worried

Yeh but I have to cut all the brackets off the diff again if I get it wrong, can't just shim the axle

Its too late for thinking, but if you have neutral castor and + or - camber, wouldnt rotating the axle either way reduce the camber by exactly the percentage the axle is rotated through 90deg? Which would mean at perfect 0 castor, the camber is the highest angle its going to be, and rolling the axle for more castor will only decrease camber closer to neutral?

Cheers
Sam

yeh you need full weight of the vehicle on the diffs, what you should have done is set castor right and made the diff end radius arm brackets to suit, i remember when flipping the radius arm brackets on top of the diff on mine, i had a problem of when putting full weight back down on the diffs it'd decrease castor by a couple degrees i think, i cant quite remember lol.
Because your setting castor to suit your truck sitting on stands at a total different height the truck will sit when the coils are in and on its own weight, creating to many variables.
But like zoltan said, when their is more weight on the diffs it might correct it a bit more.
i stand to be corrected though.

Not too late to think, that is why I'm asking now, I am at the point of setting the diff castor up, basically rotate it, tack it and check.

The vehicle is also set at the desired ride height, so in a magic world I will get a spring combo that has the car sitting at the ride height the stands are set to.

So if I got the spring height correct to give me the ride height in the photo, and the vehicle settles at that height, will camber still be effected by the weight of the vehicle?

Cheers

Well I rotated the castor to 1.5 degrees as per manual and measured the camber which is 1.5 degrees as per manual.

Just strikes me odd that factory settings would have the camber in at the bottom.

Don't know what other thought I can put into to this, castor and camber are at factory 60 series settings.

Cheers

Set it to 1 degree, or slightly more if the tyre is larger than standard and run it.. Any more is unnecessary and will compromise steering performance.

vk7ybi wrote:Set it to 1 degree, or slightly more if the tyre is larger than standard and run it.. Any more is unnecessary and will compromise steering performance.

You sound like you know what you're talking about, do you?

I need hard advice here to avoid un necessary rework later.

Cheers

Not really, I'm no expert.. The Toyota engineers are however.. Set it to what they specify. The general consensus seems to be that between 1 and 3 degrees is good for larger tyres.. The reason I say it will compromise performance is too much castor causes the tyre contact patch to decrease during turns..

If you have the axle on the wheels youll be running and the frame at the height it will finally be at, essentially the castor measured will be the same as when the vehicle is on its springs. It cannot move.

Also, the more positive the castor, the greater the tendancy for the wheels to want to self centre, this means greater effort is required to steer the wheels off centre, no good for manual steer vehicles..

vk7ybi wrote:Not really, I'm no expert.. The Toyota engineers are however.. Set it to what they specify. The general consensus seems to be that between 1 and 3 degrees is good for larger tyres.. The reason I say it will compromise performance is too much castor causes the tyre contact patch to decrease during turns..

If you have the axle on the wheels youll be running and the frame at the height it will finally be at, essentially the castor measured will be the same as when the vehicle is on its springs. It cannot move.

Also, the more positive the castor, the greater the tendancy for the wheels to want to self centre, this means greater effort is required to steer the wheels off centre, no good for manual steer vehicles..

Thanks, will try it at factory and deal with it later if it steers horrid.

Cheers

Wozza244 wrote: Im led to believe u can get some oval offset taper bearings to sit in the ball end of the axle housing which when turned to where u want it to will give pos or neg camber.
Im trying to rack my brain as to where i saw these if i remember i will get back to you.

pro axle at sangate do this. any decent truck alignment shop will probably do this.

I rekon get the castor right and sort the camber out later with offset kingpin bearings.

You can indeed get offset king pin bearings/locators.

In an ideal world you would do a cut and rotate, get your pinion angle spot on aswell as your castor (as per z()ltan).

You should also be ideally setting this at ride height with the vehicle weight on the suspension as this is the setting you want when your driving around, not on the stands at home

+dj_hansen+ wrote:You can indeed get offset king pin bearings/locators.

In an ideal world you would do a cut and rotate, get your pinion angle spot on aswell as your castor (as per z()ltan).

You should also be ideally setting this at ride height with the vehicle weight on the suspension as this is the setting you want when your driving around, not on the stands at home

Thanks for the advice it's all appreciated, the vehicle is at my desired ride height on the adjustable stands, I just need to get lucky with some standard springs or get some customised ones. Sure I said that further up the thread