Building a Custom Jeep Front Axle

By Bill "BillaVista" Ansell
Photography: Bill Ansell
Copyright 2008 - Bill Ansell
(click any pic to enlarge)

Introduction

Hybrid Dana30/Dana 44 axle, locking hubs, and high clearance steering.

 

Part One - What and Why?

OK - here's how this whole mess came about.

I wasn't happy with handling of my XJ with the lift somewhere in the 7 to 8" range.  Control arm angles are to steep, and the stock steering is way past its safe and effective limits.  Here's the evidence.

These are not good angles for the steering linkage. And this is at static ride height. It was time to do something about it.
 
These are not good control arm angles either. The handling was horrible! It was time for either an expesive long-arm conversion, or a cheap and easy leaf-spring conversion. Guess which I chose!
 
Under the rubber boot the wear on the tie-rod-ends was bad.
 
Note the ovalling of the socket caused by excessive angles.
 
More excessive wear.
 
Not good!

There were also other problems.  Despite setting the front CV shaft angles properly, with the new Detroit Locker up front, the vibrations were so bad that both my mirrors vibrated loose and fell off, smashing to pieces while I was driving.  Not good!.  Also, with the pinion rotated up, I had almost zero caster, and this made the steering worse.  Imagine steep control arm angles, steep steering linkage angles, a full time locker, zero castor, not to mention the worn tie rod ends, and 2 badly worn balljoints !!  Something had to be done.  I decided I needed:

1) Locking hubs

2) New stronger steering linkage with improved angles

3) To address the suspension geometry

4) Some way to regain caster while retaining proper driveshaft angles.

But how to get all this, and at what cost?  Options include a custom built front axle, some kind of long arm coil suspension, Warn hub conversion, and more.  Ultimately I rejected all of these options for the following reasons:

1) I'm cheap, and all of these would run into the thousands of dollars.

2) I like to design and build my own stuff, and I like to document it too.

3) I had just installed the 4.56 gears and Detroit Locker, which cost me a pile, and I hadn't even wheeled them yet.  The market where I live is such that there would be almost zero chance of my selling them and regaining my money, or anything like it, and besides, I wasn't ready for the emotional cost of dumping a mod I had long wished for, finally gotten, and never really tried out.

So - that left me having to work with what I had, but getting what I wanted, and all at a reasonable cost, and labour I could do myself.....easy eh?

After much research and contemplation, the Jeep Wizard himself came to my rescue with inspiration and knowledge.  Paul Weitlauf was an enormous help, and his very own XJ D30 upgrade formed the basis on which I would base my plan.  You can read his article at: http://www.outdoorwire.com/4x4/jeep/tech/axle/xjupgrades/index.htm

Here's the plan:

1) Remove the XJ's steering knuckles, and replace with early Chevy 1/2 ton 4x4 (K10) open knuckle Dana 44 parts - this would give me locking hubs and the basis for high clearance steering

2) Build my own high clearance steering linkage from DOM tubing and parts sourced from the local race shop.

The issues with this plan are:

1) You can't just bolt the D44 parts to the XJs knuckle yokes. You first have to cut off the XJ's knuckle yokes and replace them with a knuckle yoke that will accept the Dana 44 steering knuckle and balljoints.  Luckily, a CJ Dana 30's knuckle yokes will both fit on the XJ tubes, and take the D44 balljoints.

2) BUT - the "throw" of the CJ knuckle yokes is different so custom length inner shafts are needed.

3) A custom seal will be required on the inside of the passenger side of the diff, as the stock seal is in the disconnect housing and will not work (too large - the original disco shaft is HUGE at this point)

Read on to see how I overcome all this and more!

Part 2- Definitions

Before I go into detail with my project, it's appropriate that we agree on some common terminology for the front end, as there are some different names in use for the same parts.

Parts Definitions (listed in order from the inside of the axle out)

1. Knuckle yoke – the yoke welded onto the end of the axle tubes, either houses the  balljoints (XJ,YJ,MY,TJ,ZJ,) style or takes the balljoint stud (CJ,Scout,1/2 Tons etc.) Sometimes called the "inner knuckle" or "C".

2. Balljoints

3. U-Joint

4. Stub shaft – the “short” outer part of the axle shaft on the outboard side of the U-joint

5. Knuckle – the bit attached by the balljoints that does the steering (some call this the spindle, I imagine because in cars the actual spindle is fixed to it)

6. Caliper bracket / dust shield (if not part of the knuckle) e.g. in Ford F-150 the caliper mount (sometimes called caliper stand) is all cast as part of the knuckle.  In Early 70’s Chevy ½ tons, the caliper bracket bolts onto the knuckle.

7. Spindle – The round part that bolts to the knuckle and on which the wheel bearings seat

8. Rotor – The front disc brake rotor

9. Hub – The metal body that attaches to the rotor, houses the wheel bearings, and through which the spindle and stub shaft pass.

10. Lockout – The manual locking hub.

Part 3 - Parts You Need

First, in order to be able to bolt on the flat top knuckles that are the heart of the system, you need to have the right knuckle yokes on your axle.  The right kind are the “older” style that have small holes in them into which the ball joint studs are pressed.  Another way of describing it is that the ball joints point “up”. That is, where the body of the ball joint is pressed into the knuckle, and the studs, point up and go through the knuckle yoke.

CJs, Scouts, Pickup trucks, Full-size Jeeps, and just about every Dana44 front axle have these yokes.  However, XJ, YJ, MY, TJ, and ZJ models Jeeps do not – they have the knuckle yokes that hold the ball joint with the ball joint pointing “down”.

This doesn’t mean you’re out of luck if you own a late-model Jeep, just that you’ll have to go through the extra step of swapping on the correct knuckle yokes first (not for the timid, but an opportunity to custom-set caster), and it means you’ll have to use custom inner axle shafts, as the “width” of the correct, older knuckles is different.

The CJ Dana 30 front axle from where I got my knuckle yokes.
 
CJ Dana 30 knuckle yokes have the right "spread" between the ball joint holes to mount the Dana 44 outer knuckles.
 

CJ Dana 30 knuckle yokes, cut off and ready to be cleaned up for transplant onto the XJ Dana 30 front axle.

To free the knuckles from the stubs of axle-tube that are still in them in this pic, I first cut and ground everything off flush with the back face of the knuckle (blue arrow). Then I made to cuts to "section" the remaining tube inside the knuckle (cut lines indicated by the yellow lines), before tapping out the bits of tube with a BFH.

Before I start describing parts lists, a couple more "definitions":

Crossover steering is where the drag link and tie rod are separate and not connected (otherwise you have an inverted-T or inverted-Y setup).

True Hy Steer is where both the draglink and tie rod are over the springs (in reference to a Spring Over Axle leaf spring setup):

The parts required for Crossover Hy Steer with 5x5.5 bolt pattern are as follows:

Parts required for High clearance steering (this list applies equally well if you already have a D44 front):

1) Flat top knuckles – from ’74 – ’76 Front open-knuckle D44 axles, found in Chevy K10, Jeep Waggoneer, and narrowtrack Jeep Cherokee SJ’s.  The Chevy knuckles are the best choice as the drivers side will already have 3 holes drilled and tapped.  I used '76 Chevy K10 4X4.

From this pile I used the '76 Chevy K10 outer knuckles and the '85 Ford F-150 lockouts (manual locking hubs).
 
Comparison between the CJ Dana 30 knuckles (top) and the Chevy K10 knuckles (below).
 
This is the original setup on the Chevy K10 driver's-side knuckle, showing the Chevy steering arm attached (the end has been cut off the steering arm).
2) Balljoints - that match the knuckle you use, they are probably all the same (all D44 open knuckle).  I used Spicer Ball joints for '76 Chevy K10 4X4.
Lower balljoint part # 505-1156.
 
Upper balljoint part # 500-1070. 

3) U-Joint.  Standard D44 U-joint.  Spicer part number 297-x (non greasable) or 297-1X (greasable) or the newer forged-joint 5-760x. Exotic choices include "high strength" offerings from High Angle Driveline and CTM Racing.

4) Stub shaft.  That matches the knuckle you use.

Since I was using Chevy K10 knuckles, I also needed to use the Chevy stub shafts.

K10 stub shaft on the left, F150 stub shaft on the right.

 

Side-by-side comparison of the '85 F150 (top) and '76 K10 (bottom) stub shafts.

They are slightly different due to the 1/4" longer Chevy spindle.

5) Caliper bracket / dust shield.  The Chevy or Wagoneer style are the best.  The single piece doubles as a caliper bracket and heavy duty rotor dust shield
This pic shows the knuckles, stub shafts, lockouts, brake pads, and caliper brackets I used in the project.
 

This is the Chevy K10 brake parts.

The caliper bracket and dust-shield are one large integrated piece.

6)  Spindle - Again, that matches the Knuckle.  You can use the Ford D44 stub axle, but it is 1/4" shorter (I'll explain why in a second) so you won't be able to install the c-clip on the end of the stub axle, which may mean that the seal where the stub axle enters the back of the knuckle/spindle may not be as good. The Ford stub shaft is shorter because the Ford spindle is shorter because the Ford caliper bracket is a cast part of the knuckle, whereas the Chevy caliper bracket is bolted onto the spindle, and is about a 1/4" thick.
'76 K10 spindle on the left, '85 F150 spindle on the right.
 

The Chevy and Ford spindles are different and cannot be interchanged. You need to use the one that matches the knuckle you are using.

In other words, the outer knuckle, spindle, and stub shaft must all be matched (from the same vehicle).

8) Rotor and hub.

I used the Ford rotor and hub assembly  to get a 5x5.5" wheel bolt pattern.

You can use the Chevy or Jeep Wagoneer hub and rotor for a 6x5.5" bolt pattern.

In other words, the hub-and-rotor assemblies can be interchanged (Ford on a Chevy spindle or Chevy on a Ford spindle) to get the wheel bolt pattern you want.

10) Bearings and seals.  If you go with the mix n match parts like I did, use the Chevy wheel bearings, spindle bearings, and spindle seals, but the Ford inner wheel bearing seal (that fits in the back of the Ford Hub).  Actually, they are all the same except the inner wheel bearing seal.

Timken Part numbers:

76 Chevy / 85 F-150 inner wheel bearing: Set 37 

76 Chevy / 85 F-150 outer wheel bearing: Set 45

 76 Chevy / 85 F-150 Front Axle Spindle Outer oil seal 722109

 76 Chevy / 85 F-150 Front Axle Spindle Inner oil seal 722108

 76 Chevy / 85 F-150 Spindle bearing B2110

 Inner wheel bearing seal (fits in back of hub) Chevy 24898 Ford 24917

11) Lockouts (manual locking hubs) - The same for the Ford, Chevy and Wagoneer - Warn Premium part number 20990.  I used the Warn Ford lockouts that came from the junkyard with my 85 F-150 hubs.

Parts required if you are converting a late model Jeep D30 like I did:

1) Inner-knuckle yokes from a Scout or CJ D30 - Alternatively you could use the knuckle yokes from the donor D44, and either source or have machined a piece of tubing with the correct inside and outside diameters to slip over the D30 axle tube, and into the D44 knuckle yoke.  I don't know if the correct sizes are available in common stock, or if it would have to be machined.

2) Custom length inner axle shafts.  This is a kicker.  Because of the different style of knuckle yoke, the distance between the center of the U-joint and the vertical line through the upper and lower balljoints is about an inch shorter in the CJ yokes than it is in the XJ/YJ/ZJ/TJ/MJ  yokes.  This means the stock inner axle shafts, even if you have the 297x U-joints, will be too long.  They can't be shortened because of the design of the shafts.  The only way around this would be to use a sleeve of some sort, preferably with the D44 knuckle yokes, that lengthens the axle tube itself the same amount so you can use the stock inner shafts (assuming they take the 297x U-joint, as they will have to, to mate with the 297x jointed D44 stub shaft) or some other length so that a different 297-jointed stock inner axle could be used. 

Here are some 297-jointed stock inner axle dimensions from the Warn page www.warn.com to help you figure this out if you want to try that:  Note that the stock XJ shafts are the same as the Wrangler - Right 32.25", Left 16.63".

INNER AXLE SHAFTS:

Application Year PN Length Splines U-Joints
Wrangler (Right) '87+ 38875 32.25 27 297X
Wrangler (Left) '87+ 38821 16.63 27 297X
Wagoneer (Right) '74-79 38808 14.69 30 297X
Wagoneer (Left) '74-79 39339 33.19 30 297X
Wagoneer (Right) '80-84 39459 15.8 30 297X
Wagoneer (Right) '80-84 39461 32.12 30 297X
Jeep CJ (Right) '72-81 38803 14.14 27 297X
Jeep CJ (Left) '72-81 38789 27.01 27 297X
Jeep CJ7 (Right) '82-86 38805 15.82 27 297X
Jeep CJ7 (Left) '82-86 38804 28.69 27 297X
Scout II (Right) '71-80 38808 14.78 30 297X
Scout II (Left) '71-80 38790 32.91 30 297X
Bronco (Right) '67-71 38807 28.06 27 297X
Bronco (Left) '67-71 38806 18.44 27 297X
Bronco (Right) '71-77 38810 27.94 30 297X
Bronco (Left) '71-77 38809 18.31 30 297X
F-150 (Right) '78-79 39144 33.91 30 297X
F-150 (Left) '78-79 39143 18.91 30 297X
Chevrolet Dana 44 (Right) '73-78 39529 36.13 30 297X
Chevrolet Dana 44 (Left) '73-78 38809 18.31 30 297X
Chevrolet Corp (Right) '79-87 39253 35.46 28 297X
Chevrolet Corp (Left) '79-87 39252 19.15 28 297X

I bought custom length D44 front alloy axles with beefed up yokes and machined for full U-joint circlips, from Moser Engineering, that they cut down and splined to fit in my D30 Detroit Locker.

Long-side and short-side custom inner axle shafts.
 
The D44-size axle shafts were machined down to fit in my D30 differential.
 
Beefy custom axles.
 
 
 
The "ears" are machined so that a full circlip can be used to retain the U-joint caps.
 
 

 

 

The stock XJ axle shaft dimensions.
 
Dimension for the custom chafts I ordered from Moser (pictured above).

Part 4 - Doing the work

Step 1 is cutting the stock XJ inner knuckles off the axle, without damaging the axle tube, as the axle tube is not being shortened.
 
It helps to cut a relief section out of the yoke (inner knuckle).
 
Once I knew how far into the inner knuckle I had to cut, it was time to cut all the way around the knuckle.
 
Seperating the old yoke from the axle tube.
 
To make the cut all the way around the yoke, I had to get the ears out of the way.
 
Hackin stuff out of the way with the Sawzall!
 
This is what it looks like when the cut all the way around the yoke is finished, and the yoke is pounded off with a hammer.
 
Inner knuckle cut free and pounded off.
 
The old weld that held the original inner knuckle on must be ground off.
 
Test-fitting the CJ D30 inner knuckles on the XJ D30 axle tube.
 
Like the other side, I just wanted to get the bulk of the stock yoke and knuckle out of the way so I could make a better cut around the yoke without cutting into the axle tube.  The Sawzall worked fine, but the chop saw is fun too!
 
Here the axle is ground down and cleaned up and is ready for the new inner knuckles.
 
Fitting on the "new" CJ D30 yokes and setting the caster.  Note that the axle is clamped in the vice with the pinion angle set for my lift (i.e. the way it needs to sit in the truck) so I can get correct pinion angle AND correct caster.  I stuck with the factory XJ spec of 7-8 degrees of caster.
 
Well, there's a couple of errors in the pic labels.  On the D30 the disco housing and pumpkin are NOT nodular iron, they are CAST.  I tried welding the reinforcement sleeves to the housings using a 7018 rod, and they cracked as they cooled.  I should have used a high nickel content rod.
 
Here the CJ inner knuckle (yoke) is tacked in place.
 
I used some 2.5" IS schedule 40 pipe to sleeve and reinforce the axle tubes while I was at it.
 

Once the new inner knuckles are welded in place, the D44 outer knuckles are bolted on using the D44 ball joints.

Here this has been done, and the steering arm, caliper bracket, and spindle are in place.

 
Here the Chevy brakes, Ford hub and rotor are installed, with full time slugs in place (before I cleaned up and installed my Ford Warn manual lockouts).
 
The final thing required was to install an inner oil seal in the passenger side of the diff.  I bought a stock driver's side seal, then took my air grinder, and hogged out the axle a bit, till I could fit the driver's side seal in there, and seated it in some RTV.
 
I drove it around for a while with the stub shafts installed but no inner axles, as I waited for Moser to make and ship my custom shafts.  I didn't wait long - to my door in 3 days!
 

Of course, now I have 2 different bolt patterns front and rear. The new 5x5.5" in the front and still the stock 5x4.5" in the rear.  I bought a single 5x4.5" to 5x5.5" adapter (1" thick)  from http://www.performancewheel.com/

It's a work of art for $50.  My spare wheel and tire has a 5x5.5" pattern, so if I need it on the rear, I just bolt on the adapter first.  You can't do it the other way around as a 5x4.5" wheel or adapter won't fit over the front hub.

Part 5 - Brakes

Once the axle was complete, I had to make the new Chevy 1/2 ton brakes work with the stock XJ system.  I chose to use AN-4 racing stainless steel brake hoses.  The race store I bought them at had all the necessary fittings to adapt them to both the stock XJ hard lines and the Chevy caliper.
 
This is how it works.
 
Placement of the 90° caliper fitting is critical as there is not a lot of clearance back there when everything's installed.
 

Next 3 pics show how the Chevy brakes are superior to the stock XJ.

Bigger brake pads.

 
Bigger calipers.
 
Bigger calipers.

Part 6 - Reference Material

Here are some pics from some manuals that I referred to during the project, and that may help you with yours.

Dana 44 IFS Front Drive Axle - Bronco & F150 with Manual Hublocks.
 
SJ Full-size Jeep Front D44 Axle Components.
 
SJ Full-size Jeep Front D44 Inner and Outer Knuckles, Balljoints, and Spindle.
 
SJ Full-size Jeep Front D44 Brake Rotor, Wheel Hub, Wheel Bearings, and Drive Slugs - exploded view.

Total:


Get a GoStats hit counter

BillaVista.com

web count
Get a GoStats hit counter