Cut & turn knuckle Measurement # needed

[hammered]

Hey Guys.

In the works of cutting and turning the knuckles on a housing here.
Going to SOA my 40 and found a housing at the wrecker.
Doing a pre-prep and then just swap the old 1965 axles aand housing out with this newer one that will be ready to mount.

Thing I need is the measurement on how much to turn the knuckles.
Once had a link to a page that had a super simple method.
Cut, mark and measure so many mm. for the turn.
Lost the link with my old Laptop.
The Tec links have nothing on how much to turn once cut.

-I am running 4'' shackles and not going to reverse the spring mounts
-Stock springs.
-33'' tires and will be 35'' next set of boots.

Any help or the link on how much turn would be awsome

As is it is cut have made 2 marks Punched and zip cut lined to work off.
the insert is cracked and moves freely now have tweaked it and just holding to weld it all up.

I have searched the forms for this and could find the #s.
Something like 2 mm or was it 12mm offset.


Note to any of you that use zip cuts.
WALTERS makes the best zip cut I have ever used. They are thin and last forever.

Thanks for any info.

 

[DirtyLittleSecret]

sorry I cant help you with this, but am giving it a bump cause I'm interested!

 

[Cruiserdrew]

I don't think it's that predictable or simple. I think 14 degrees is an old rule of thumb, but you still need to be careful welding the perches and making sure caster is correct. You could consider doing the cut, setting it in place and getting the pinion angle you want, then welding the perches to fix the pinion angle, then turning the knuckles back to achieve 2-4 degrees of caster.

 

[Mad Chemist]

Ditto, don't assume rule of thumb is going to work.

Set the axle on jackstands and with full weight on the springs turn the pinion up till it's pointing at the tcase, tack perches in place, then do the turn.

Good luck!

 

[cruiserbrett]

you can do the math pretty easily IF you have the suspension setup exactly as its going to be once sprung over.

take measurements with a ruler and angle finder, lay it out on the concrete floor with some painters tape, and measure the angles with a carpenters square. from there its simple.

 

[rockcod]

I don't think it's that predictable or simple. I think 14 degrees is an old rule of thumb, but you still need to be careful welding the perches and making sure caster is correct. You could consider doing the cut, setting it in place and getting the pinion angle you want, then welding the perches to fix the pinion angle, then turning the knuckles back to achieve 2-4 degrees of caster.

Drew is right on.

Check out page 4 of [thread=163844]"Sully" 72 FJ40[/thread] link.These numbers were figured with the weight of the cruiser on the axle.

Good luck.

 

[dgangle]

Ditto to all said. If I can add my $0.02...

If you elect to do it this way, be certain that when you have the axle under the truck and taking measurements/setting pinion angle, spring perches location and caster angle that you have the weight of the truck on the springs/axle as these measurements will change as the suspension is flexed out.

What I did was get all the setting close, tighten the U-bolts, set the weight of the truck down on the springs and re-measure. If not right, jack it up, loosen U-bolts, re-adjust, etc. I had to go through this a couple times to get the final settings/measurements I wanted.

Also remember that if you are putting in lift springs (prolly shouldn't be with a SOA), they will settle over time so take this into consideration as well. The caster and pinion angles will change as the springs lose some of their initial lift.

 

[hammered]

Thanks for all the info and feedback.

Will take your advice. all of you.
Sounds like I should turn the casters once it is all on.
For some reason I have read mixed reviews on the cut and turn with 33' tires.

Anyhow I am going to load the weight on it and then set it all up.
really not all that much more work.

For some damb reason I had this stupid idea it could lay it all out before hand.

Again Thanks for all the help.

Sg