4340 Chromolly D2 Rear Shafts

[D Chapman]

I think the stock you should start off with should be no bigger then the splines. Then, behind the splines, the axle should have a Waisted design so that the shaft is equel to or lesser than the diameter of the spined root - lesser than would be ideal.

 

[mightymg]

HAHA I like the titles on the pictures. DUMB< almost as DUMB, and right. HAHA LOL thats good!

 

[rdoane]

I think the stock you should start off with should be no bigger then the splines. Then, behind the splines, the axle should have a Waisted design so that the shaft is equel to or lesser than the diameter of the spined root - lesser than would be ideal.

Where did you get that diagram from? Is there any text that accompanies that picture? Just wondering why the diameter of the splines should be larger than the shaft itself.

Dan, you wouldn't happen to have a list of available diameters and lengths for 4340 would you? IIRC you use 4340 on your tie rods. The problem is that the diameter of the Rover shafts is 1.24", which is a random size. The short shaft is close, made out of 1.25" which is pretty common, but you still have to taper; and the closest size we could find in the right length for the long side was 1.5".

I'll defiantly investigate the reasoning behind the smaller diameter shaft size and see if I can find a piece of steel that works.

 

[D Chapman]

I use 4140.

You can buy 4340 in most diameters and in 21 foot sections, +/- 6".


0.25" ALLOY STEEL 4340 NORMALIZED COLD FINISH, TURNED ROUND


0.375" ALLOY STEEL 4340 NORMALIZED COLD FINISH, TURNED ROUND


0.4375" ALLOY STEEL 4340 NORMALIZED COLD FINISH, TURNED ROUND


0.5" ALLOY STEEL 4340 NORMALIZED COLD FINISH, TURNED ROUND


0.625" ALLOY STEEL 4340 NORMALIZED COLD FINISH, TURNED ROUND


0.75" ALLOY STEEL 4340 NORMALIZED COLD FINISH, TURNED ROUND


0.875" ALLOY STEEL 4340 NORMALIZED COLD FINISH, TURNED ROUND


1" ALLOY STEEL 4340 NORMALIZED COLD FINISH, TURNED ROUND


1.063" ALLOY STEEL 4340 NORMALIZED COLD FINISH, TURNED ROUND


1.125" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


1.25" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


1.375" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


1.5" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


1.625" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


1.75" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


1.875" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


2" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


2.25" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


2.375" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


2.5" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


3" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


3.5" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


4" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


4.5" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


5" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


5.75" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


6" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


6.5" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


7" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND


8" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND

 

[D Chapman]

http://pirate4x4.com/tech/billavista/PR-BV60/index1b.html

 

[Herkvet]

Where did you get that diagram from? Is there any text that accompanies that picture? Just wondering why the diameter of the splines should be larger than the shaft itself.

Probably to let the shaft take the brunt of torsional loads vs the splines.

 

[rdoane]

http://pirate4x4.com/tech/billavista/PR-BV60/index1b.html

The engineering makes sense, however:

• Directly from the article: "There are, in fact, no aftermarket companies that I'm aware of making replacement shafts for Dana axles with this particular profile feature, the proper neckdown - not even Superior. I asked aorund amongst all my contacts and tried to find out why - nobody's talking. I suspect that the added complexity and expense of this design, especially when balanced aginst the wide design margin afforded by the high quality materials (heat treated 4340) in use amongst the top companies, and the trad-off in strength vs shaft diameter, when coupled with an analysis of the shafts required duties (in a rock-crawler, as opposed to darg car etc.) that the decision is that it's just not worth it."

• An example of the above quote: http://pirate4x4.com/tech/billavista/PR-BV60/Materials/Long_inner_dim.jpg. That Superior D60 inner is milled in nearly the same manner as my long shaft.

• 1.25" ALLOY STEEL 4340 NORMALIZED ROUGH TURNED ROUND; thats closest to stock that I would feel comfortable using. The next size down is 1.125" and even though that would allow for the correct neck-down approach, I would much rather run 1.25" and mill off a hundredth of an inch.

With that being said, I will most likely procure some 1.25" in the right length for the long side rather than using 1.5".

 

[D Chapman]

How are you doing the splines? Cut or rolled?

 

[rdoane]

How are you doing the splines? Cut or rolled?

That I do not know. I picked up the shafts in Greenville and had to drive right back to Clemson and had no desire to carry from the parking lot to my dorm room. I'll be back at my car later tonight so I'll look at them then.

 

[racerwad]

How are you doing the splines? Cut or rolled?

wondering the same. thanks for answering all the questions.

 

[rdoane]

How are you doing the splines? Cut or rolled?

The splines are cut. Didn't even have to look at the shafts.

"There are VERY few companies capable of rolling splines. The only two I know of are Dana/Spicer and Superior Axle and Gear. The drawback (for a manufacturer) to rolling splines is that not only is the equipment very expensive, but it is also time-consuming to set up, so that it is only feasable to roll splines in axles in large batches. This explains why so few aftermarket axles have rolled splines, and why virtually no custom shafts will have rolled splines."
- http://pirate4x4.com/tech/billavista/PR-BV60/index1b.html

 

[LR Max]

The reason for starting out with a larger shaft is because of the need for the mounting flange to be against the unit bearing. THAT is the kicker. If that hadn't been needed then 1.25" stock would have been used.

Indeed, you can use 4130 but the prices for the axle shaft blanks are about the same, so pay the extra 10 bucks and get the nicer stuff.

On the hardening deal: when custom shafts are made, they gotta cut for the splines so the hardening is also cut away. This is how EVERY aftermarket axle shaft shop does it. So yes, the hardening is milled off, but it would be like that anyway at the splines.

Once again too much nit picking over nothing. Bottom line is that they are made out of 4340. These shafts with a detroit, some lower gearing, and 35" or under and you WILL NOT have a problem. Anything over 35 and you are gonna start having other troubles.

If you do...well then you are quite special.

On the asking of R&P, the higher the gearing (i.e. 3.54 instead of 4.11), the stronger the R&P.

 

[nosivad_bor]

http://www.grobinc.com/

I buy rolled spline shaft from this place. They are easy to work with.

I must mention that you keep saying that the shafts are MILLED and it's driving me nuts, the proper nomenclature is TURNED

I am inspired to make my own shafts now. Thanks for the idea !

 

[justinhaaga]

this is funny.... critique the man. this stuff is stronger than stock and according to him is cheaper than GBR. :smash:

as for gears

facts:
4.11 GBR:
1. They are reverse cut
2. They are treated

they have 3 teeth less on the pinion, stronger than stock? yes.

 

[Herkvet]

Once again too much nit picking over nothing. Bottom line is that they are made out of 4340. These shafts with a detroit, some lower gearing, and 35" or under and you WILL NOT have a problem. Anything over 35 and you are gonna start having other troubles.

Amen!
The price is right, and stronger than stock.

 

[LR Max]

facts:
4.11 GBR:
1. They are reverse cut
2. They are treated

they have 3 teeth less on the pinion, stronger than stock? yes.

If this is the truth then let then ok! I am not familiar with GBR equipment but if it is made with superior methods then it should be good to go.

 

[bri]

I have had literally a shitpile of discussions with GBR about this very topic. Funny over the past 10 years I never remember hearing that 4.11 are absolutely, without a doubt stronger than stock. In theory-- MAYBE. In practice-- not what I have experienced. But then again I am just an old fart with fading memory.

And... don't get me wrong here. As far as I am concerned, Bill is THE BEST. I can't tell you how many times this guy has helped me out. If/when I want gears, without a doubt I will go to Bill.

The reason to have 4.11 gears is not strength IMO, its power.

Its all about trade offs.

 

[rdoane]

The shafts are installed along with a Detroit. A few more adjustments had to be made, but overall, they fit well. This weekend at Gultches they will get tested fully.

However, I'm pretty sure sure that I'm not going to sell them.

I've heard that in the near future some alternatives to GBR's shafts are going to be released a reasonable price. These shafts will be very similar to my design, and will be able to be produced much faster.

With that being said, if anyone is interested in making their own shafts for the D2 similar to mine, I would be glad to share my experiences; what I would of done different, and what worked for me.

 

[benlittle]

ANy updates??

 

[ChicagoDon]

ANy updates??

Richard likes big hard shafts in his rear :rofl: