Rolled spline Vs Cut spline

[wheeler4x4samota]

We was sent some axles to test 30 splines 4340 chromoly thru harden. 2 with cut splines an 2 with rolled splines all 4 from the same bar. The 2 with the cut splines broke at about 8,910 ft. lb. an 120* of twist, the 2 with the rolled splines broke at about 8,945 ft. lbs. and about 110* of twist. I thought this would be good tech to know. Of course you guys all know i like breaking stuff.


from bobby long

 

[boardbysled]

So, they are nearly identical in strength.:awesomework:

 

[zukkev]

Good to know wheelerbobby4x4samotalong!!! :redneck:

 

[jprcrpr94]

Good to know wheelerbobby4x4samotalong!!! :redneck:

:haha::haha::haha::haha:

 

[super samurai]

not sure the spline is the breakingpoint more then the through hardend. most axles have a soft center and only the outside is hardened. i have hade some axles cut and replined, for example 6o axles resplined to toyota 30 spline and it went past the hardening and i had to have them heat trated and tempered. curious if bobbys are through hardened?

 

[longfield]

not sure the spline is the breakingpoint more then the through hardend. most axles have a soft center and only the outside is hardened. i have hade some axles cut and replined, for example 6o axles resplined to toyota 30 spline and it went past the hardening and i had to have them heat trated and tempered. curious if bobbys are through hardened?

Yes some axles are through harden and most are only harden on the outer service. The through harden axles are stronger and take more twist degrees. All of our axles are through harden. Yes the splines will be the weakest point thats were they all broke.

 

[82toyomud]

Yes some axles are through harden and most are only harden on the outer service. The through harden axles are stronger and take more twist degrees. All of our axles are through harden. Yes the splines will be the weakest point thats were they all broke.

Were they breaking in the middle of the spline section or at the tapered section of the spline?

 

[longfield]

Were they breaking in the middle of the spline section or at the tapered section of the spline?

They were breaking in the middle of the splines.

 

[64FJ40]

Cut splines are considerably cheaper and easier than rolled/broached, right?

For the 0.4% difference in strength, I wouldn't complain about cheaper and easier.

 

[Bunk1]

They were breaking in the middle of the splines.

I wanna see this breaking thingy live..Also, I need to drop by pretty soon and see if you could look at my 60 birfs.

 

[Bunk1]

Cut splines/rolled/broached

http://www.youtube.com/watch?v=OG4nYuksiYU&feature=related

http://www.youtube.com/watch?v=WgMZQD79Mzc

Never seen external splines broached, But ive drawn a broach thru parts and plunged a broach into parts

http://www.youtube.com/watch?v=ffPsFIxFUMs

 

[Binder]

Yes some axles are through harden and most are only harden on the outer service.

Yes it depends on the material the axle is made out of what hardening process is used. Rolled splines and case hardening is faster and easier for mass production so that's how the factory usually does it.

 

[64FJ40]

http://www.youtube.com/watch?v=OG4nYuksiYU&feature=related

http://www.youtube.com/watch?v=WgMZQD79Mzc

Never seen external splines broached, But ive drawn a broach thru parts and plunged a broach into parts

http://www.youtube.com/watch?v=ffPsFIxFUMs

Gotcha. Thanks.

So for one-off machine work, cut is easier/cheaper I take it?

And rolled makes more sense for mass production?

 

[Bunk1]

Gotcha. Thanks.

So for one-off machine work, cut is easier/cheaper I take it?

And rolled makes more sense for mass production?

Buying a mill/index head and special cutter is cheaper than buying a spline rolling machine.

 

[82toyomud]

They were breaking in the middle of the splines.

Thats slightly surprising, but good to hear about.

 

[Bunk1]

Thats slightly surprising, but good to hear about.

He explained it on pirate, The total engagement on his machine is like 1 1/4 but the shafts were splined 2 1/2 inches.

I wonder how much movement there is on the side gear with a spider knuckle and crazy steering.

 

[jeepmauler]

He explained it on pirate, The total engagement on his machine is like 1 1/4 but the shafts were splined 2 1/2 inches.

I wonder how much movement there is on the side gear with a spider knuckle and crazy steering.

food for thought.........A year and a half ago I bent my rear full float 60 spindle in a violent roll. When I unbolt the axle flange,from the hub, the axle springs up and binds in the spindle.The shaft has to be PRYED out with a couple crow bars and then pounded back in w/ a 5#. Everytime the axle shaft rotates it's puting a tremendous,off axis,load on the Detroit side gear. I worried about @ first but it's been 1.5 years and still going strong.....nuts.

Also,shafts breaking @ the end of the side gear splines sucks balls.

 

[82toyomud]

He explained it on pirate, The total engagement on his machine is like 1 1/4 but the shafts were splined 2 1/2 inches.

I wonder how much movement there is on the side gear with a spider knuckle and crazy steering.

Yeah I read that after I posted that. It makes sense now... Definitely not ideal. I think I would rather have the splines stronger, and the axle act like as the spring its designed to be.