• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Cut and Turn

Desert4x4

NAXJA Forum User
Location
Phoenix
Just wondering if it's possible or if anybody has cut and turned the inner C's on the Dana 30 while was in the car.

Also, 8 degrees is the correct caster angle?
 
I don't see how and get it done right. I would want a stripped housing on a jig before I started. 8* of castor is alot, there is no set #, what are you try to achieve?
 
To cut the Cs requires removing the axle for access all the way around the tubes.
Mounted in the Jeep, the springs and too many other things are in the way, plus how would you weld it?.
It doesn't take that long to drop the axle .
FSM specs on caster are 5.25 - 8.5 degrees, with 7 degrees being preferred.
 
Hell I built this jig just to locate the control arm mounts, but you can see how hard it is to get to the "C" welds when it's off the rig.
FH000011_zpsgkviyadu.jpg
 
it may be doable, but will be a whole lot easier with it out and on a stand. just grinding the weld off would be difficult with it mounted up

I did a sleeve and gusset job on mine with it mounted, but was fairly easy.
 
it may be doable, but will be a whole lot easier with it out and on a stand. just grinding the weld off would be difficult with it mounted up

I did a sleeve and gusset job on mine with it mounted, but was fairly easy.


Define "easier"?
IF your labor to remove and reinstall the axle are not factored in and IF you already have a stand to mount the axle on while you work on it and IF you have the additional shop space, then one could probably justify the process as easier to complete with the axle removed from the vehicle.

Placing tall jackstands under the axle and leaving the axle mounted to the links is pretty simple and effective.

Being able to rotate the housing to cut thru the factory weld and reweld the knuckle post-rotation might be easier, but definitely not a requirement to do the job correctly.
 
I'll likely be doing it on my D30...since I can and it's easy enough.

Having it in the vehicle may make it easier to rotate, but still a pain to cut.

As far as the caster, OEM would be around 7, but more doesn't really hurt.

I've though about putting mine around 10°.
 
Define "easier"?
IF your labor to remove and reinstall the axle are not factored in and IF you already have a stand to mount the axle on while you work on it and IF you have the additional shop space, then one could probably justify the process as easier to complete with the axle removed from the vehicle.

Placing tall jackstands under the axle and leaving the axle mounted to the links is pretty simple and effective.

Being able to rotate the housing to cut thru the factory weld and reweld the knuckle post-rotation might be easier, but definitely not a requirement to do the job correctly.

doing a cut and turn on my 44. can't imagine doing it with the axle under the jeep. you're 4 bolts away from being able to pull the damn thing. but if that works for you, have at it.
 
I'll likely be doing it on my D30...since I can and it's easy enough.

Having it in the vehicle may make it easier to rotate, but still a pain to cut.

As far as the caster, OEM would be around 7, but more doesn't really hurt.

I've though about putting mine around 10°.

Not addressed in this thread is the change in coil spring orientation that will take place when the inner C's are rotated.

If using the stock coil mounts on the axle, which position the coil forward of the axle tube and not on top of the tube like aftermarket mounts, your coil spring will be bowed forward, post-rotation of knuckles. This can cause the coil to rub on the inner bump tower and also cause the spring to not perform ideally.

My simple solution was to create a metal ramp in the front of the factory coil mount which matched the radius of the coil, to raise the front edge of the coil to the point where the coil body was no longer bowed.
 
Not addressed in this thread is the change in coil spring orientation that will take place when the inner C's are rotated.

If using the stock coil mounts on the axle, which position the coil forward of the axle tube and not on top of the tube like aftermarket mounts, your coil spring will be bowed forward, post-rotation of knuckles. This can cause the coil to rub on the inner bump tower and also cause the spring to not perform ideally.

My simple solution was to create a metal ramp in the front of the factory coil mount which matched the radius of the coil, to raise the front edge of the coil to the point where the coil body was no longer bowed.

The only thing that will be left from the OE D30 on mine is C's, tubes, and housing :D
 
Not addressed in this thread is the change in coil spring orientation that will take place when the inner C's are rotated.

If using the stock coil mounts on the axle, which position the coil forward of the axle tube and not on top of the tube like aftermarket mounts, your coil spring will be bowed forward, post-rotation of knuckles. This can cause the coil to rub on the inner bump tower and also cause the spring to not perform ideally.

My simple solution was to create a metal ramp in the front of the factory coil mount which matched the radius of the coil, to raise the front edge of the coil to the point where the coil body was no longer bowed.

didn't even think about that, but you're exactly right. taking mine down to the tube and rebuilding it. also stretching it 2" with offset coil pads.

another concern is link mounts and their new geometry. you could get by using longer upper links, but still going to look like a hack job with bowed coils....

So it's either rotate the C's a small amount (less than 5°) so the above issues aren't a problem, so you get negligible gain in caster angle. or pull it out, strip it down and do it right. My target is 10° of pinion angle with 5° of caster. Haven't plugged it into a calculator yet... but those are where I think I'll end up.
 
didn't even think about that, but you're exactly right. taking mine down to the tube and rebuilding it. also stretching it 2" with offset coil pads.

another concern is link mounts and their new geometry. you could get by using longer upper links, but still going to look like a hack job with bowed coils....

So it's either rotate the C's a small amount (less than 5°) so the above issues aren't a problem, so you get negligible gain in caster angle. or pull it out, strip it down and do it right. My target is 10° of pinion angle with 5° of caster. Haven't plugged it into a calculator yet... but those are where I think I'll end up.

I added 4* of caster via knuckle rotation, which is hardly "negligible gain". This provides a massive improvement in how your rig handles.

The real world impact is the difference of your rig wandering all over the road and the steering wheel not returning to center VS cruising at 75mph with a thumb and finger on the wheel with zero wander.

Another benefit of positioning new coil buckets over the tube is that you gain space to extend the trackbar to a mounting point on the inner C, which improves the geometry.
 
Last edited:
I added 4* of caster via knuckle rotation, which is hardly "negligible gain". This provides a massive improvement in how your rig handles.

The real world impact is the difference of your rig wandering all over the road and the steering wheel not returning to center VS cruising at 75mph with a thumb and finger on the wheel with zero wander.

This is the reason I've entertained adding more.

Hell, many U4 rigs running 100+ across the desert run upwards of twice that (15-20° caster).
 
If we define "caster" as the difference in pinion angle vs the C's, I'll have 15 to 18 degrees

are U4 rigs running similar numbers? or are they running 15° of actual caster? where the C is rotated aft 15° relative to level ground?
 
keep in mind those guys are potentially doing 100 mph through the desert with 40" tires and full hydro steering.

additional castor beyond the factory spec can really help with wandering issues on larger tires and improves the steering's tendency to "return to center." but too much can/will result in heavier steering input. for a jeep driven on the road and mechanical steering (no assist or full hydro) 8-10 degrees of castor should be more than enough.
 
very few road miles on mine. In fact, just got it back to street legal. I'll be adding hydro assist in the near future. What should my target be with assist? will be running locked 37's on a 44
 
if you arent driving it at road speeds or racing, then added castor really is of little benefit. if you want to adjust the pinion angle and give it a little castor so you can run around town, 8-10 is plenty.

i think i ran my 44 at 7 degrees, at highway speeds.
 
Back
Top