That, my friends, is the "beef".

The guts of an ultimate Dana 60 front axle.

A great combo - Superiors and CTMs

Comparison of stub-shaft splines.  Spicer top and Superior bottom.

Note:  To meet the deadline for this article, my stub axles had the splines hobbed, normal production Dana 60 stub shafts will have rolled splines.

...the perfect combination!

Superior and CTM.

Splined end of Superior Cr-Mo alloy Dana 60 axle, short-side inner; showing exclusive "torque equalizing" profile (more dimensions and comparisons below)

The result is that the 2 different length front axle shafts have much more similar load carrying capabilities than the stock configuration; meaning ultimately that the whole assembly is more durable and reliable.

Splines and profile of Superior Cr-Mo alloy Chevy Dana 60 long-side inner axle shaft .

To meet production schedules, these axles were hobbed.  Normal, non-custom length inner axles may have rolled or hobbed splines, depending on production schedules.

Look closely and you will see the rainbow-effect of the heat treatment of the yokes (which few, if any, other companies can or will do) - this is a major contributor to the strength of the Superior shafts.

Non-hardened axle shaft yokes deform under hardcore 4x4 loads, bearing caps spit out, U-joints break and shafts rupture.  For serious use, you need through hardened yokes.

Yoke strength - not only THE most critical aspect of a front axle shaft - but also where the Superior shafts shine the most.

Space inside the knuckle is extremely limited, but Superior found a way to add even more material to the yokes in the most critical areas.

They are larger than Spicer D60 shafts in every dimension I measured. The following pic and table show the results of my measuring:

Here's a comparison shot of the Dana60 30 spline stub shaft, the stock Spicer 35 Spline Dana70 stub shaft and the Superior Cr-Mo Alloy stub shaft. The dimensions in the pic are:

Comparison of Old Spicer, New Spicer, and Superior Alloy Axle long-side inner shafts. Pic illustrates Superior shaft.

Comparison of old, Spicer, and new Superior Alloy Axle short-side inner shafts:

It seems the way to cut manufacturing costs, and therefore retail prices, is to skimp on the material, process and/or quality control.

Here we see the cheap offering next to the Superior shaft. Note the lack of material around the yoke bore in the other shaft.  Worse than that - several of these other shafts have ben measured by reputable sources, and it has been found that the dimensions in areas like the material surrounding the yoke bore vary by as much as 0.100" between samples....that's a TENTH of an inch !

Again, the difference is obvious.

So my question now becomes, if design is substandard, manufacturing tolerance poorly controlled, and the product made in some un-named place by an un-named company - what assurance do I have that material selection and grade are up to par and properly controlled - to say nothing of the complex machining and heat-treating processes.

Answer is - it turns out Grandma was right - nothing in life is free, and you get what you pay for.  I'll stick with Superior!

For clarity I have illustrated the names I shall use for the parts of the CTM U-joint and kit in the following pics to the left.

Here is a front view of the joint...

...a side view of the joint.

The main body I will call the "cross", the bearing journals "trunnion", and the bearing caps "caps".

The supplied hardware kit.

Simple stuff, sure enough, but by now you know I'm a fanatic for clarity and accuracy.

In the "tools needed" section of the official instructions with the CTMs say "shop press or good machine vice."  I had a piece of junk bolted to the bench where a vice should go, so I took this opportunity to rationalize the purchase of a nice new vice.

Hey - when Axle Jack says get a good vice...you get a good vice!

You'll want one with jaws that open at least "

9. Install snapring in snapring groove using snapring pliers (yellow arrow)

(snapring, snapring, snapring.....hmm, funny - after you say it to yourself 36 times the word loses all meaning!)

...too get the trunnions to pop through the bores.  But it will fit, just be patient, and don;t hammer or force anything but feel free to apply a little persuasion with a brass drift.

Not only is this trickiness more than made up for by the fact that there are NO needle bearings do drop, crush, get trapped etc  - but if you're struggling, remember that the parts fit tightly because of their maximum size and strength - which is exactly what you want!

17.  Stop when the snapring groove is inside the yoke

Don't forget to frequently pause and admire the amazing beef of your super-cool new axles and U-joints ;-)

AWESOME!

Very cool, VERY beefy, - form and function in one sweet package.

installing the CTM's was a JOY! I have never had such an easy time installing U-joints. I didn't have to force anything, no dropped needles, no getting the whole thing assembled and one cap wont sit right and you realize a needle has fallen over and you have trapped it - jeez I hated that! I love these joints. Down with needle bearings I say!

Corrosion protection is extremely important for mechanical assemblies subjected to cyclical loads and subject to fatigue, because small surface imperfections and corrosion form stress raisers, from which fatigue cracks can develop.

Despite the "anti-corrosion" black oxide coating the Superior axles come with, they are subject to corrosion.  After just a couple of weeks in my shop they bagan to show light surface rusting.

This is nothing new - I'm convinced it's a California thing - how could a Cali company develop a corrosion resistant coating sufficient for the North Atlantic Canadian coast?  I live in one of the most corrosive environments there is - if you don't, be thankful - EVERYTHING rusts here!

As such, I decided to take the extra protective step of painting my axle shaft assemblies before installing them.

To paint the steel in a meaningful manner that has any hope of lasting, it is VERY important to use a high quality self-etching zinc primer first.  It costs 3-4 times what the cheap grey primer does, but if you skimp here, you may as well not bother as only the self-etching primer will properly adhere.

Slide axle assembly through knuckle and into housing. Take care not to disturb the inner axle seal with the inner end of the shaft.

There is a caution in the official CTM installation instructions that mentions the possibility of having to remove the grease fittings from the ends of the caps prior to installing the assembly through the knuckle and into the housing.  I found that this wasn't necessary on my axle (1980ish Chevy D60 outfitted with Crane knuckles.)

It is critical that you carefully check clearances once everything is installed.

The knuckle must be cycled from lock to lock while the axle is being rotated (a helper is enormously useful here) while you carefully check to make sure that the axle/U-joint assembly doesn't contact any part of the knuckle or axle housing at any time.

And also check to make sure that there is no contact possible between the top of the yoke ears (yellow arrow) and the bottom of the yoke on the opposite shaft (green arrow).

If there is any interference, you will be able to see, hear, and feel it, and you must adjust your steering stops to eliminate it.  It is wise to allow a little extra clearance to make sure nothing contacts under hard use where things may compress a bit.