Chromoly axles

[suzukigav]

Hey, I was wondering if anyone knows what material "chromoly" axles are made from.
Is it just 4140 or 4340? And does it get heat treated or case hardened at all?
I am going to make some and I want to know the best material is to make them from.
Any info would be helpfull.

[GRPABT1]

The ones I have seen are 4340 http://www.lowrangeoffroad.com/index.ph ... axles.html" onclick="window.open(this.href);return false;

[Gwagensteve]

I think everyone is now making the inners in 4340.

What are you going to make exactly though? fronts or rears?

I'm running Trail tough DT's in the front. Mine have the CTM made 4340 inners, but we also have some of the older ones in the club (which were apparently nothing special material wise) and they are holding up fine. It's important to remember that every supplier of upgraded front CV's uses the same CV. Only the inner axles are unique to each supplier.

My rears are heat treated EN-26. We have about 5 sets of them in the field now and they've been beaten on like red-headed step children and have been fine.

I enquired about 300M, and whilst it's immensely strong, it apparently it has some unhelpful qualities. It's hard to heat treat without distortion, and it's apparently not all that hard (strength and hardness aren't the same thing) so apparently if a side gear or drive flange broke, it's quite possible the splines would be damaged even if the axle itself didn't fail.

Steve.

[suzukigav]

Thanks heaps guys. En 26 is much tougher than 4340 anyway. And the price of En 26 isn't too much more than 4340 at the moment. So I think I will be making mine from En 26 conscidering we have heaps out at work at the moment. I am going to be making both fronts and rears. I let u guys know how it goes.

[Gwagensteve]

What are you doing about the front CV?
Are you building a full floating rear or are you welding the flange on the end?

It's great to hear people making driveline parts. Good on you!

Steve.

[suzukigav]

No for the rears I am going to turn the whole axle from 1 solid piece so no welding will be required. I think that will make it stronger too. As for the fronts I am going make the cv's aswell aswell.

[redzook]

No for the rears I am going to turn the whole axle from 1 solid piece so no welding will be required. I think that will make it stronger too. As for the fronts I am going make the cv's aswell aswell.

if you can do this i will be amazed take photos if you do

[Gwagensteve]

X2, and to tell you the truth, I think it's a massive waste of material. That $$$$$ axle, milled from a solid round of EN-26, will be 30%-40% weaker than the same axle set up as a full floater, with better wheel bearings, disc brakes etc as a side effect of using front hubs in the rear.

If you have the capacity to make axles as CV's, for god's sake make a floater for the rear. You won't regret it.

Steve.

[Gwagensteve]

X2, and to tell you the truth, I think it's a massive waste of material. That $$$$$ axle, milled from a solid round of EN-26, will be 30%-40% weaker than the same axle set up as a full floater, with better wheel bearings, disc brakes etc as a side effect of using front hubs in the rear.

If you have the capacity to make axles as CV's, for god's sake make a floater for the rear. You won't regret it.

Steve.

[suzukigav]

Well if u must know the truth. I hadn't heard of a full floating rear set up til starting this thread,
steve. Can u tell me a little more about what's involved with making a full floating rear set up?
And as for turning the whole thing out of a single piece of material. We do shafts out at work out of en-26
all the time and as a result of making lots of shafts u will get the occasional one that one of the bearing journals
is turned undersized so the shaft is useless and a waste piece of material, and those wrecked shafts are what I'd use
to make my axles from.

[Gwagensteve]

To make a full floater, you need an adapter plate welded to the axle housing to turn the drum brake backing plate bolt pattern into the front hub bolt pattern.

You also need a plug that's the same OD as the wheel bearing but bored to take a front inner axle seal. The gets pressed into the wheel bearing space on the rear diff housing.

Then you bolt a front hub onto the rear axle and you are away.

The axle shaft is then just a stick with the same 26 spline at each end.

Here's some photos of a mockup. This is using a Vitara rear axle housing (superior - stronger tubes, bigger R&P, much heavier bearing housings, and really cheap from wreckers)



The 10mm thick laser cut adapter plate bolted in place. This is fully welded once bolted up.



A front view of the fitted adapter plate.



With the front hub attached



Showing the front caliper bracket



With the hub removed so you can just see the spindle.



With a rotor and caliper dropped on and a GV or 1.0 sierra front drive flange fitted.

I've only done these to date with vitara rears. I'm going to be doing a couple of WT rears the same way shortly.

We have caned the living daylights out of this setup with 34/35" tyres and it's sound. My car is radius arm coil rear with very high antisquat so it forces its tyres down very hard and I regularly pull 7500rpm 3rd low clutch dumps. The axles have been fine in situations I was breaking stock rear axles.

The obvious advantages of rebuildable, serviceable wheel bearings, the ability to remove the axle without touching the brakes (or even with the wheels on the ground) and added axle strength are all wins.

I also carry a spare front hub assembly with me ( It's my spare tyre carrier). As front and rear are now the same, if I have a wheelbearing collapse, I can just bolt a new hub on in minutes.

Steve.

[oozuk]

how much to buy this full floater setup ?

[11_evl]

very nice work steve.
if you can wip up a set to suit bundera rear id buy a set and sort my own axles

[Gwagensteve]

how much to buy this full floater setup ?

I'm not offering them for sale. I arranged to have the laser cut brackets made and worked it out. However, the parts pricing is as follows

Vitara rear housing and diff complete from a pull it yourself wrecker: $120 (from memory)

Axles in EN 26 (Pair) $610
Adapter plates: approx. $20
Pair of front hubs, rotors and calipers : No idea
Seal adapters for the inner axle seals: $200 (this sounds steep but the ones we had made were art - O ring sealed and a lovely fit.

So there's a grand there before you put a locker in, sort the brakes, or any of the other widgets.

The catch is in the labour. There quite a lot of work (and ideally a large lathe and/or jig) in cutting the bearing housing off of one tube, cutting the tube down, then re welding the being housing. Also the diff cover needs to be cut off and rewelded, as the housing is flipped upside down.

The housing is flipped because vitara rear diffs are slightly offset the opposite way to a sierra. By flipping the housing, the vitara's short side axle tube is the one that's cut down so the offset ends up very close to stock sierra.

Total Traction drivelines in Moorabbin, who makes the seal adapters and axles will also straighten the housing once the welding has been done and face the adapter plates once it's all finished to ensure it's all parallel and square. I think Matt charges about $150 to do that. I didn't do that on mine, but my car isn't driven much and runs a spool. With a lock right or airlocker I think this would be important.

There's also a bunch of little jobs that also need doing - brake lines, flares on the hard line, a new diff breather etc. Like every job, what's cheap in theory quickly becomes expensive in practice.

Yes, it's quite possible that people have swapped in hilux diffs for less money, but not with 5.12 gearing, rear disks and the light weight of this setup.

Steve.

[joeblow]

people need axles made?......

[lump_a_charcoal]

Showoff.

[BlueSuzy]

very nice work steve.
if you can wip up a set to suit bundera rear id buy a set and sort my own axles

Looks good doesnt it!

All i could think of is using cruiser disc hubs with adaptors with my bundy rear, to get the floater. But then my rear offset/ track would be larger..

Floaters would definately be a good thing if i break something. My car won't be trailered.