putting 1 tons under my lx have a few questions

[GLTHFJ60]

Does RCV publish strengths of their shafts like this? Supposedly done by an independent lab. Looks like stock D60 35 spline shafts are stronger than the strongest land cruiser inner axle.

http://www.fourwheeler.com/how-to/s...toyota-truck-4runner-suspension/photo-16.html

 

[Mace]

Most axle manu won't post actual data like Bobby did.

IIRC that was for the smaller bell Mini/60 style longs, not the 80 series longs.

 

[GLTHFJ60]

Most axle manu won't post actual data like Bobby did.

IIRC that was for the smaller bell Mini/60 style longs, not the 80 series longs.

You're right, good point. However, the failure point was the stub shaft with the longfield in the above graph, not the bell. Are the stub shafts the same diameter / spline count between the 80 and 60 birfields?

 

[Mace]

Yes, 30 spline.

 

[scottryana]

Well if that is just a D60 shaft what's the ujoint? Some of the very strong ujoints can't be run in a fulltime four wheel drive setup. The 80 series upgraded birfs and shafts are great for what they are. I would guess if you are breaking the 80 joints it is likely you will need more than a stock D60. The D60 RCV's are almost 3x the cost of the 80's

 

[GLTHFJ60]

I am making the assumption that the "axle shaft" is actually the assembled inner axle, not any one shaft, thus, the u-joints are included. The u-joint is obviously the functional equivalent of the birfield.

My point with this graph is that if the longfield failure was the stub shaft, and the stub shaft are the same between the 60 and 80 birfields, then the 80 inner axle assembly is no stronger than a 60 inner axle assembly, and therefore both (including longfield versions0 are weaker than a stock D60 setup.

 

[Mace]

The D60 joint in that application was a stock Spicer joint. They are huge and strong.

And yes, the 60 and 80 series longfields were almost as strong but breaking before "stock" D60 components (that's kind of a misnomer, the stock D60 stubs were 30 spline, but can be swapped for stock D70 35 spline stub shafts).

If you add alloy shafts and joints, D 60's get very strong.

Fulltime 4wd setups are generally not a consideration when you are adding the 300M shafts and U joints to a D60..

 

[scottryana]

This chart shows the 30 spline as 8500lbs and the stock 60 at 6500lbs, this was from Bobby's axle breaking demonstration at Jamboree

PRODUCT / ................................................. FT.LB. TORQUE/.... % TWIST
Yukon 4340 Dana 60 35 spline short side axle.........12,000 ..................130
Stock Dana 60 35 spline short side axle .................6,500 ....................35
Yukon 4340 Dana 44 30 spline short side axle ..........5,800 ...................35
Stock dana 44 30 spline........................................5,00 0.....................35
Yukon 4340 Birfield Eliminator kit (ear failure)............5,500......................50
Longfield 4340 30 spline (shaft failure)......................8,500............... ......175
Longfield 4340 27 spline........................................6,50 0.....................75
Stock Toyota Birfield.......................................... ..4,200 .....................45
Stock Toyota Inner Axle.......................................5,000 .....................45
All Pro "Profield"........................................ .......... 3,500 ....................30
Stock toyota Transfer Case Output Shaft.................2,500 ....................65
Longfield treated Transfer case output shaft.............2,500.....................20
Longfield 4340 Transfer Case Output Shaft...............4,000......................25
All Pro Transfer Case Output Shaft..........................2,500 ......................60
Marlin "treated" Transfer Case Output Shaft..............2,500 ......................10
Stock Toyota Hub............................................... .5,800/
Longfield Treated Toy Hub ....................................6,800/

 

[Mace]

Not surprising, the 30 spline 4340 was not available when Bobby created that old graph. Or when I was watching him break shafts at the Benders Jamboree.

Also it's a good idea to note if those breaking numbers were at angles or straight ahead.

The 30 spline longs are the benchmark of what a toyota axle can do. I hope that they still are the same product they were a short time ago. But you also have to start seriously upgrading the other pieces of the axle to sustain the stresses that the chromo (or 300m) 30 spline longs can survive. That's where the D60 comes into play.

Also, IIRC, Bobby's machine maxed out on the Alloy D60 stuff (unless he built another bigger, badder machine which is possible). So that may not be a max number on the D60 stuff.

 

[scottryana]

Bobby said he broke all the u-jointed shafts straight ahead with a solid bar through the ears of the flange and he broke the birfield joints at full lock. He said if he tested standard spicer u-joints they would just beak the u-joint and not test the shaft.