Proper procedure for caster adjustment documented for you.

[reamer]

So I had an alignment done last fall cause my 73 likes to wander, no Bump-steer, No death wobble, every bushing (front and rear) is new. new tie rod ends, 4 degree "C" bushings, new PS box and pump, New track bar bushings, new Ball joints, Everything new. 2.5' Lift.
Here are the original numbers in the first photo) there is only 0.7 caster built into the axle By Dana (but that's with the help of 4 degree C bushings too!)

Now some say go 7 degree C bushings, but that makes the pinion angle worse, Some say use adjustable upper ball joints, but that is a Band-aid, and could only provide a max of 1.5 degrees, which is still no good.

So you must pull the axle from the truck and grind off the welds between the knuckles and axle tubes, (photos 2 and 3).
Now I was looking for about 3.5 Degrees more of caster, so this is where the math comes in....

Axle tube is 2.75" dia. = 8.64" circumference, so divide that by 360(degrees in a circle) = 0.024" per degree. x 3.5 degrees = 0.084" So a 3/32 dill is 0.093" which is what I used.

Now grind off the whole weld between the knuckle and tube, then whack the knuckle a few times so it "cracks" and reveals the seam between the tube and knuckle. (photo 4).
Now drill a hole with the 3/32 bit in the seam (but not all the way through the tube, which is photo 5.

Now the best part, slam the crap out of the upper ball joint casting and tilt the top ball joint towards the rear until you "offset" the hole edges, (photo 6). Weld it up all the way around the knuckle and reinstall the front end again.

Brought it for a new alignment numbers, Bingo! 4.9 degrees caster (the right way) photo 7.
Cruised down the highway at 70 mph and 1-finger steering!
Caster went from 0.7 to 4.9 degrees.... Beautiful.

 

[bax]

You stated you had already drove it after the fix. If you had cut your wedges off first, then fixed the pinion angle and tack the wedges back. Then done the work on the outer C's , you would of fixed everything. I mean great improvement but to fix the pinion angle you will now have to do what you have done over again. But getting correct caster is a great improvement. Good job.

 

[reamer]

My pinion angle right now is 5 Degrees, with the 4 degree C bushings, well within Spicer's recommendation of up to 10 degrees angle, so no wedge cut needed, just caster value needed.

 

[bax]

So you used the 4* bushings to get your pinion angle to 5* and then cut your outer C's and rotated them back to 7*. Thats sounds like a good fix to me.

 

[toddz69]

No need to cut wedges off if you rotate the outer C's enough, which appears to be the case in this instance.

Congrats on doing this - it's really the right way to fix the caster issue.

Todd Z.

 

[reamer]

Thank you, But if your rotation to "fix" caster gives you an extreme pinon angle, then it would have to be a 2-prong operation as Bax mentioned, Wedge cutting to get a good pinion angle, then cutting the knuckles for caster....

 

[Rustytruck]

If you have a magnetic protractor can you hang it under the lower ball joint and give us the angle you get Please I would greatly appreciate it. I suspect it will get the same measurement as your final adjusted number.

 

[bchesley]

This has been documented on several times including one of my post. The correct way to do this is to remove the outer C's and reinstall the axle. When you install the axle use the appropriate degreed bushings to set you pinion angle. Once the pinion has been set you reinstall the outer C's to your desired caster and weld it up.. I have a factory pinion angle with 7 degrees of caster on a 3.5" lift. Any legal speed locked in 4x4 and not a single vibration.

 

[bax]

This has been documented on several times including one of my post. The correct way to do this is to remove the outer C's and reinstall the axle. When you install the axle use the appropriate degreed bushings to set you pinion angle. Once the pinion has been set you reinstall the outer C's to your desired caster and weld it up.. I have a factory pinion angle with 7 degrees of caster on a 3.5" lift. Any legal speed locked in 4x4 and not a single vibration.

I built a high pinion axle like this. No issues. I have a build thread here somewhere.

 

[lars]

This has been documented on several times including one of my post. The correct way to do this is to remove the outer C's and reinstall the axle. When you install the axle use the appropriate degreed bushings to set you pinion angle. Once the pinion has been set you reinstall the outer C's to your desired caster and weld it up.. I have a factory pinion angle with 7 degrees of caster on a 3.5" lift. Any legal speed locked in 4x4 and not a single vibration.

This. It's been beat to death.

Start by doing what ever it takes to get the pinion angle right. Usually that's as simple as dumping the high degree C bushings, IE going from 7 degree urethane bushings back to 2 degree urethane bushings, or even rubber bushings with no caster correction. Unless the axle was way out of spec from the factory (it happened) that will take care of the pinion angle.

Now if you want to be really accurate with getting caster right, drive gingerly to an alignment shop and get the caster checked. With the caster numbers known, proceed with cutting off the inner C's and rotating them as required to get 6-ish degrees of caster. A lot of work and worth every minute.

As has been repeated regularly it's like a miracle cure. I did mine in 2005, what a difference.

 

[DirtDonk]

Thanks for the comparo reamer. A good before-and-after story.

What tire size are you running? Exact diameter if you can take a tape measure to it when you have time.
Just wondering what the actual toe-in measurement is in inches rather than degrees. You said yours steers really well, so would like to compare that number as well.
Toe-in makes a surprising difference in the subtle feel of general driving. Not only out on the highway, but right down to driveways and parking lots.

thanks

Regarding the use of rubber C-bushings... I don't know why nobody makes rubber with a shoulder/flange on them like poly bushings have to keep them from spitting out under stress.
Most will never experience a lost C-bushing on the street, but it used to be a big thing out in the boonies and especially when racing.
Short of a shoulder on the bushings we need a simple bolt-on flange to capture the C-bushings inside the radius arms.

Paul

 

[Shimmy]

just curious, what do you guys think a shop would charge for this? I think i'll need to do this, but dont have the welding skills unfortunately.

 

[DirtDonk]

Likely depends more on where you live than just about anything else. A couple of members have found shops to do it for under $250 bucks if i remember, but most would probably charge closer to $750-$1,000 I'm betting. At least in a big city situation.
Well, most shops in a big city would just turn you away and be done with that kind of talk. But the ones that are willing to take it on are going to price it per the local market. Big city = more expensive.

The reason I say most shops won't take it on is that anymore most shops don't know what you're talking about. They just look at the book and say "sorry, that alignment is not adjustable" and leave it at that. Never having done any custom work on aligning something with a solid axle.
Maybe up your way you'll have more luck. You happen to be in a rural/farm region by any chance? If so, you need to find a welding shop or farm implement repair facility. Someone with basic knowledge of cutting and welding "stuff" from cars to fork lifts to tractors to custom frame work.
Maybe even a big-rig shop?

That's just my idea. Hopefully others have had experience searching down a shop that would do it.

paul

 

[Shimmy]

Yah Paul, i hear ya. I spoke with a local shop and they were like, "sure we can do that!" But i'm always so hesitant to trust shops with my cars. Prices are probably up the butt where i live. All these tech folks driving housing and costs way up!!!

 

[reamer]

Are you going to grind and adjust, and just need a welding?
Or are you looking at the whole job?
What are your Caster numbers now? You MUST have an alignment done now for the current numbers, then we figure it out from there...
Where are you located?

 

[Shimmy]

i'm in WA, Maple Valley... about 40minutes from Seattle. I could do the cutting and adjusting, but at that point, i figure i might as well have someone else do it for the sake of transporting the axle and such. my caster right now is .5*

part of the issue here is a lot of shops dont want to do part of the job... they'll only accept all of it.

 

[toddz69]

just curious, what do you guys think a shop would charge for this? I think i'll need to do this, but dont have the welding skills unfortunately.

It's been so long now that I can't remember what year it was (guessing 2006-2007 time frame) but as I recall, I paid about $400 for a local old-timey machine shop to do the rotation on mine. They had a lathe with a bed on it so large that the D44 easily fit in it and they cut the C's loose on the lathe, rotated them, and then welded them back up.

I took it home and bolted it in and my friend and I decided just to check the angles to be sure. Sure enough, they hadn't rotated the pass side enough - it was 2 deg. off! So out it came and back to the machine shop it went. The guy didn't believe me at first but when I whipped out my angle finder and showed him, he clammed up and fixed it for me. And yes, I checked it before it left the shop for the second time.

I need to go by and see if the place is still in business. As I recall, it had dirt floors in part of the building and you'd have sworn Calvin Coolidge was still president when you stepped inside. All this in downtown Phoenix - the 5th largest city in the country!

Todd Z.

 

[reamer]

0.5 degrees is No Good. You need about 4.5 Degrees more.....

 

[Shimmy]

0.5 degrees is No Good. You need about 4.5 Degrees more.....

exactly!

 

[armynavy17]

i'm in WA, Maple Valley... about 40minutes from Seattle. I could do the cutting and adjusting, but at that point, i figure i might as well have someone else do it for the sake of transporting the axle and such. my caster right now is .5*

part of the issue here is a lot of shops dont want to do part of the job... they'll only accept all of it.

If it were me, I wouldn't be looking for a mechanic shop. I'd look for a machine shop, ranch and farm repair, metal fabrication shop.

Even if the shop themselves aren't interested, the guy in the back welding all day could very likely be looking to make a little money on the side. If you can pull the axle and drop it off at their house/shop all the better. Should just need to know which direction you want them turned and how many degrees.