NEW AXLES FROM WILKINSON

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Gee Larry thanks, another thing to add to my "not needed but want" list.

...I just Machine My Own! This is just a small part of what We do Down at 'LFW', Stockton, Ca. All Day Long!!...

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Gee Larry thanks, another thing to add to my "not needed but want" list.

OOOPS. I hope this didn't bump buying a set of my GRP 4 tail lights down a notch.

Had the same e-mail from Wilkinson and made some enquiries, on what seemed to be a 'too good to be true deal".

'Allegedly' these are Argentinian machined, Chinese steel. Wilkinson apparently purchased a lot of 1100 to keep the price down. It would be nice if someome independently checked the metallurgy, the Chinese are renowned for not meeting specs on high grade steels.

Here is what I pruchased from Mark Williams Ent

4340 Forged Steel Solid Axles American Made 750.00.

I'm putting my extra 300.00 in insurance that they will not break.

Not knocking Wilkinson ..because I purchased the rest of the double roller bearings and hardware that no one else had in stock.

Well if they break, you know where he lives!

I have the Williams axles also and know the story behind the their development. They're made from the same forging blank used in his drag racing products. The 4340 forging should have significantly better material qualities, especially at the critical location where the flange transitions to the axle. These have been around for over 20 years and there are a lot of them running around in cars today. PPC was the vendor that commissioned the introduction but the technical talent that did the development work was a third party. They're a high quality part.

Kelly

I agree .. I have been using MWE axles for at 15 years in drag racing applications and never had an issue with any of there products. I think this is one part on the car not to cut corners on cost if you plan to put any type of stress or horsepower at the rear wheels.

Well, I will post my opinion on this topic.

I have received a few calls from my DeTomaso buddies asking about forged axles versus billet axles because of this recent Wilkinson offer. So, to go on record I will post a response here.

I am a profession Engineer with a Masters Degree. My area of specialization is in aeronautical Structures - with over 26 years of experience. Material properties are an integral part of this area of engineering. I am Director of Engineering for the Canadian Government Civilian Airline.

Forging is the process by which metal is heated and is shaped by plastic deformation by suitably applying compressive force. Usually the compressive force is in the form of hammer blows using a power hammer or a press to form a part close to its final appearance. Forgings yield parts that have high strength to weight ratio-thus are often used in the design of aircraft frame members.

Forging refines the grain structure and improves physical properties of the metal. With proper design, the grain flow can be oriented in the direction of principal stresses encountered in actual use. Grain flow is the direction of the pattern that the crystals take during plastic deformation. Physical properties (such as strength, ductility and toughness) are much better in a forging than a billet piece machined to the same geometry (read shape)), which has, crystals randomly oriented.

The principle stresses, in the case of the axles result from the transmission of torsional loads. These are primarily resolved as principle shear stresses. The shear stresses are highest at the surface of the shaft proportionally reducing to zero at the neutral axis or shear centre at the centre of the shaft. There is relatively little strength added with a solid centre. Alternatively, weight is added by having material in the centre of the shaft which does proportionally little good. That is why good designs will hollow out the centres – saves weight. But, there is a compromise. There is a weight saving - but it costs more to machine the centre out.

Cost is an important factor in the design of a part as well. If few parts are required, it is much better to machine the part out of a billet of material. The amount of machining required is costly. Imagine taking a block of wood and wittling out a candlestick. You would have a lot of work to do and you would have created a lot of wasted shavings. The relative cost is acceptable because only a low number of parts are required. But each part costs about the same to make. If a large number of parts are required, the higher tooling costs to prepare a forging is offset and shared over a large number of pieces. A good forged part will be pretty close to the final shape so that there is minimal machining - minimal relative machining cost. Which help explains why, as claimed earlier, Wilkinson made over 1000 axles.

A good design will cater for the material, geometry and how the part is made - whether machined or forging.

One more thing: All things being equal, Forgings normally provide better durability – meaning fatigue performance. Mechanical fatigue performance is also a design consideration for a shaft.

Lets put it this way … how many of us always look for drop forged tools. We insist on this is because this tells us something about the strength and durability of the tool. Early blacksmiths hand forged swords and other items where the best material properties were important.

Personally, given the nature of the part, and the great price, it is an offer hard to pass up. I placed my order.

B. Goyaniuk

I consulted with my technical advisor Mel and here is his responce:

The solid 4340 forgings should be significantly stronger in yield strength than most cold rolled alloys. EN19 is a British nomenclature that is best equated to 4140 here in the US. In a direct comparison of properly heat-treated metals, the 4340 will have better ultimate and yield strength that the 4140. I would feel fairly comfortable with either one as I suspect the original axles would have been made from a 1018 or 1020 steel, and thus would be significantly weaker than both the 41xx and 43xx series steels. On a personal note, In torque the tube offers greater strength then solid if the steeIs were the same but as we know TORQUE is no the only stress an axle experiences ! I would be curious as to the weight difference between the solid and the bar axles. QUOTE

The flange thickness, the quality of the foriegn steel, the porocity of the steel was of equal value or known ?

Ron

If it is 4340 or 4140 steel it doesn't matter if it comes from Zluto it is still the same.
Virtually all of the aftermarket stroker cranks are being cast or forged in China.

How many have you heard of that have failed?

In addition, even if it is inferior 4340 steel. It is still stronger then the original 1018 steel axle by a lot.

AND, if you need more. What do you want for $358 a pair? A new car? Geeze, chill, baby... AND it includes the nuts!

Doug valid point after I read it again ...we are splitting hairs ... great observation .. thats why we pay you the big bucks ... to keep us young bucks in line.

LOL