setting the pinion angle on spoa

[noel b]

can somebody give me somehelp on setting the height/angle of the pinion when doing an spoa on a 85 drover hard top I have bigballs perches, and am using stock springs and 1.5" extended shackles. m&m high steer and am putting 33" mtrs on backspaced rims, Do I just measure the height of the pinion the add 5-10mm(and take for a drive to see if there is any vibrations) or can you get castor bushes/wedges for them and if so who has them ? any help would b appreciated sorry if this has allready been asked thousands of times.

[bazooked]

on mine i had bout 6" of lift i rotated the rear up 4deg and about the same with the front, also i rotated the balls on the front diff to put the castor back to standard.be carefull on the front diff as u will change the castor alot.

[Guy]

for the front set the perches to be exactly paralell to the old perches you don't really want to be screwing with the angles to much there ..

for the rear there will be about 150 different opinions .. On my setup I have the perches set to point the pinion at the transfercase yoke This allows me to run a pretty much standard rear driveshaft despite the lift (I do run a spacer though just for insurance) some will tell you that you will get horrible vibrations this way .. I have not had those issues with mine using a stock rear shaft, The issue with this setup I have found is binding the universal joint the diff end as when the springs compress and your axle wraps up a bit (A SPoa without traction bars will wrap the springs up) the uni's bind ..
Others will say do the above, but use a double carden jointed shaft (hilux front d\shaft)
Another idea is to set the rear pinion angle the same as the T/case end rear angle ...

But I would be looking at some form of axle wrap control as well ...

Honestly If your asking these kinda quiestions .. I would seek advice from a pro .. as fixing any screw ups from this point may be a few $$$ that would be better spent on getting a pro to set it up and burn em on ..

(Have a look for another one of my posts .. should have a few pics as well)..

[Guy]

http://www.outerlimits4x4.com/PHP_Modul ... light=spoa


some pics

[greg]

also i rotated the balls on the front diff to put the castor back to standard

I gather this may be a tad expensive - is it feasible to do it to (what i assume is) a set a NT diffs?

[Guy]

I see no need to rotate the balls at all .. I am currently running Rears in front (now about a 4 inch lift as the springs have flattened nicely) but I have run up to 6 inches of lift before with no real issues .. even with the droop I had when I had missing links I did not end up with binding .. I had to remove two inches from the gearbox crossmember to clear the driveshaft on droop ... still handled fine .. for a 6 inch lifted, softly sprung, heavy tyred, light, narrow, SWB 4x4 ..

[M&M Custom Engineerin]

also i rotated the balls on the front diff to put the castor back to standard

I gather this may be a tad expensive - is it feasible to do it to (what i assume is) a set a NT diffs?

we rotate the knuckles on zooks when we do a spring over. Rotating the pinion to point at the transfer case lessens the angle for the top uni on the front shaft.

It can be done on both narrow track and wide tracks

[OVERKILL ENG]

We run pinion angles from 10-12 degrees and rotate the knuckles to get the correct castor.
I don't care what anyone says to get the castor right on a SPOA you must rotate the knuckles.
SAM

[bazooked]

thanks sam,cost me nothing aswell

[Guy]

We run pinion angles from 10-12 degrees and rotate the knuckles to get the correct castor.
I don't care what anyone says to get the castor right on a SPOA you must rotate the knuckles.
SAM

What angle do you set the caster at ??? about 4 degree's isnt it (have not looked for quite a while)

[greg]

also i rotated the balls on the front diff to put the castor back to standard

I gather this may be a tad expensive - is it feasible to do it to (what i assume is) a set a NT diffs?

we rotate the knuckles on zooks when we do a spring over. Rotating the pinion to point at the transfer case lessens the angle for the top uni on the front shaft.

It can be done on both narrow track and wide tracks

Sorry - perhaps i didn't explain that very well...

What i meant was, there would be a certain cost involved in making those changes to a set of diffs, and perhaps it would not be feasible (money wise) to do it to a set of narrow track diffs - particularly if in 6 month / 2 years down the track the owner of the vehicle is going to upgrade to widetrack diffs or hilux's or whatever...

Certainly if something as important as steering is involved - then it should be done, but perhaps it's worthwhile looking ahead and realising that you are going to replace these diffs soon anyway, and doing the diff swap before the spring over for this reason.

Hope that's a bit clearer.

[Dozoor]

Its all a matter of what you intend doing with the thing, If it only going to do a 1000ks in a year then sure your uni angles don't make that much difference, although shafts with unequall angles at each uni might not vibrate , they will wear prematurley.
If you use the thing as a daily driver try staying within the recomended specs for a parts design, If unis on a shaft are to be reliable then keep them within the range of degrees. Or go to a cardan joint at one end.
Being a spring over conversion It will need an engineers cert ,
If your lucky you'll find one thet dosn't drive it .
But it is better if you know the consequenses of bad front end castor.,
I have seen vehicles that at 80k will not respond when steered a full turn left to right in a emergency monuver drill, eg : trying to miss somthing directly in front .
Pretty scary , 2000pounds , that takes 3 seconds to respond to steering input @ 80ks.
Larry.

[oozuk]

What sort of money will i be up for to get a WT front diff knuckle's rotated ? to suit spoa

[bigsteve]

What sort of money will i be up for to get a WT front diff knuckle's rotated ? to suit spoa

Cant you just weld on the SPOA perches at the desired angle??

Sounds a lot better than cutting WT's

[camskizook]

The way hypolux and I did mine was to sit the perches on the housing, then put the ubolts and ubolt plate on and then tighten them up. Put the wheels on and let the car settle...the perches should then be in their correct position....then tack weld the perches, take the plates and ubolts off again and then do the main welds...did the same for the front, but we didnt cut the knuckles...