Strong GU Steer box pitman arm

Joined: 02 Feb 2007

I'm after anyone interested in plate or billet steel pitman arms for the GU KOYO 104 drop pitman arm. The winch challange bous are breaking them and as I'm building a winch truck for some one will be looking into getting some pitman arms machined.

If I can get conformation on interest or purchace of said pitman arms I can get quotes on a batch. The more arms the better the price.

These will be a tough grade alloy steel folded or cut from billet steel and machined with tapers and spline as a direct bolt on replacement.

Joined: 12 Aug 2003 Location: woombye

Hey mate,

I would be interested in maybe 3, just depends on price.

Let me know, Cheers Heath

Joined: 24 Dec 2006 Location: Lawnton,Brisbane.

not 100% but aren't the gq ones stronger and thicker than gu

Joined: 02 Feb 2007

GU are thicker through the sector shaft spline where the pitman arm bolts on.

Some of the custom steering setups will not work with GQ steering boxes.

Cheers Heath, Ian was interested also. If you could ask around some of the other winch boys it would be good.

Thanks Steve.

Joined: 12 Aug 2003 Location: woombye

i will ask around and let you know, yeah 1 of the 3 was for ian.

Joined: 27 Oct 2002 Location: Esperance

Iam keen for 2 or 3 quite scary when you brake one at speed .

Joined: 02 Aug 2005 Location: Central Coast

adrian wrote:

Iam keen for 2 or 3 quite scary when you brake one at speed .

tell me about it, although i broke the sector shaft on a GQ box, at speed.

Joined: 02 Dec 2007 Location: Polar Ice cap

Has any tests been done to see what the brakeing point is of the the main shaft, it would be pointless upgrading the pitman arm if the main shaft is near breaking point when a standard GU pitman arm snaps, we have a sponsored truck that bends his GU sector shaft fairly often .
Its a lot easier to carry/replace a pitman arm than replace a steering box. Normal story you upgrade a weak point it goes to the next weak link.
Not being negative just a process that should be done otherwise myself and others could waste money on a product that makes little or no difference .
If you have done the research on the steering box than i may be interested as well.
Also do you know what "alloy" these are to be manufactured from and are they being properly heat treated? Smile

Joined: 02 Feb 2007

they will be properly manufactured. I haven't decided what grade steel yet, I havent had time to do anything about it yet either. I will take a pitman arm off this week end and take it to one of the machine shops I used to work at and get a quote.

These will be CNC machined on a 4 or 5 axis machine centre, Hence getting the numbers.

Joined: 21 Mar 2007 Location: Mornington/ Victoria

I'd be intersested in 2 depending on price, bent 2 at Ateco.
I'd bet I could move 2-3 more for good customers who compete regularly.

Cheers

Joel

Joined: 21 Mar 2007 Location: Mornington/ Victoria

Is this still on the go??

Joel

Joined: 02 Feb 2007

Sorry guys I have been real sick, it is still happening though.

Joined: 21 Mar 2007 Location: Mornington/ Victoria

Are we talking pitman arm or the sector shaft?? It's the sector shaft that twist not the arm itself. I would only be interested in sector shafts, the shaft in the box the pitman arm splines and bolts to. I've never seen a pitman arm fail but we have 1/2 a dozen with twisted shafts at work from our comp trucks.

Cheers

Joel

Joined: 03 Feb 2007 Location: South Frankston, Melbourne

i saw 2 at cliffhanger. the pitman arms both had a small chip in them that was there from the factory, and was definately a weak point. Design/mould/cast fualt?

Joined: 30 Sep 2004 Location: Capalaba

Hi Steve,

just a thought but you may be able to machine them so the tie rod end installs from the bottom the same as the GQ pitman arm - may help to reduce the angle on the tie rod.

Peter K.

Joined: 02 Feb 2007

Yes Pete that was the Idea, would have been optional on top or bottom taper or straight through hole.

I have seen plenty of GQ sector shafts break, never a GU yet. I'm not saying that they don't just I havent seen one.

I have heared of alot of guys breaking GU pitman arms though, in the same place, in the middle of the drop. If some one had a sector shaft out I could take it with me for a Quote. I dont want to strip my steer box down that far.

Joined: 12 Aug 2003 Location: woombye

Hey mate,

I have got a bent sector shaft you have have a look at. Just let me know.

Cheers Heath

Joined: 21 Mar 2007 Location: Mornington/ Victoria

I bent 2 at the Ateco, we have bent 2 in the Suzuki, GQHOON bent one at the outback, I know Trent lean broke one at round one, I beleive Andreww Cassar has bent at least one and every one was a GU box.
The sector shaft is a big problem! I'll bet there are a heap more out there too.

Joel

Joined: 02 Feb 2007

heathgu If I could borrow the bent sector shaft that would be great.

Joined: 02 Feb 2007

Pitman arms will be a no go, as they are forged and a better grade of steel would need to be profiled and inturn become to hard for conventional machining, thus too expensive.

Sector shafts will be around the $1000 mark minimum order of 10 (hopefully cheaper), I have not had a conformation on heat treatment cost yet.

Sector shafts will machined from 4340 or E110 and heat treated to suit.

They will be machined on a Mazak itergrex 200y, there is alot of 5 axis machining required on the gear section as they are tapered and crowned on the tooth face. A large peice of bar is also required to get the diametre for the gear.

Anyone interested will need to pay before the shafts are machined, I will not put any sort of warrenty on these nor be responsable for any damage caused be a failure, not that it is likely.

Just for the record I don't want any of these sector shafts nor will I be making a profit out of it. They will be made as a good will gesture to the hardcore winch challange, OBC and cliffhanger competitors (or anyone else) and will be used at your own risk. These will be the first or only batch done, depending on numbers maybe not done at all, hence no testing has been done, but if your damaging genuine parts whats the alternative aside from full hydro?

I look at it as common interest is a sport and helping people that help us with advice and knowlage.

I have not priced a genuine sector shaft but am lead to beleive they are around the same purchace price, if anyone would like to try better the price or offer an alternative feel free. Like I said I'm not fussed either way.

Steve.

Joined: 21 Mar 2007 Location: Mornington/ Victoria

Any idea as to the material of a stock sector shaft and the increase in strength from the machined replacement??

Cheers

Joel

Joined: 02 Feb 2007

I just assemble machinery now days so dont have access to a spectro analyser, typically standard parts are made from the cheapest high carbon steel that can be hardened.

You could proberly compare these to the standard CV vs Cal offroad cv, it would be similar materials.

E110 is a gear steel and 4340 is a cro/mo high tensile, as far as I know longfeilds are 4340.

The material cos on these sector shaft before they are touched is around $160 ea.

I'm just a spanner monkey like most of us on O/L so cannot afford to fund a project like this, but I can get it done with money up front. There is a certain trust involved in this, its just an option for improovement for people I thought I would throw out there.

Steve.

Joined: 02 Feb 2007

I have been talking with an engineer and it looks like the 4340 is the go. 4340 has a 22% stretch opposed to 8% for the E110.

Cost is around $860 + heat treating, if people are still interested I will keep goin on the quote. The machine shop is booked out til after christmas so there is time to think out your options.

Joined: 21 Mar 2007 Location: Mornington/ Victoria

Yes I'm still interested, I suspect we would want 2 or even 3 for our own cars here at work.

Cheers

Joel

Joined: 02 Feb 2007

OK Joel I will get the prices on the heat treatment done. I will have to book the machine for the job so that leaves 3 months for people to get the cash to me.

We will need 10 confermed purchases for the machine shop to make the shaft.

Joined: 02 Feb 2007

this is the type of machine that will be used to make the shafts.

http://www.youtube.com/watch?v=E1Fj1j8Sg1g&mode=related&search=

Joined: 02 Feb 2007

went to a metalurgist today and after doing some testing have desided to go with 4318. 4318 is a high grade E110 gear steel, these will be case hardened and cryo treated, I have to see another machine shop and hopefully can get the price down quite abit.

The metalurgist has been extensively involved with R&D on a 7000hp drag car.

The 4340 could not be heat treated to an adiquite level to suit the application to meet the properties of the 4318.

The 4340 would have been good bot the 4318 will be better, especially after cryo.

When the 4138 has been case hardened it develops an austinetic structure, due to the high nickel content, the cryo will refine the austinetic structure to give a closer grain and improoved strength.

This is the best way I can explain the process and properties said to me.