Unless you are going all 40 spline inners and outers its not worth it.... I can break a cromo 35 spline inner and have a 35 spline cromo outer live....not sure why you need a 40 spline outer only.....

save your $2k for 9" upgrades.......

 

The 300 in factory form I can agree with being a weak spot, but 9"s can be built up pretty nicely to hold up to abuse. Aftermarket case and 35 spline locker/shafts, good to go.

for the front (or rear) I think 35 spline axle would be good enough in the 40" tire range without becoming a weak point

 

The problem with 40 spline is all the extra stuff you need to buy to make it work. For $2K, get a set of RCVs. No need for spares.

 

yes that is the 2k for extra stuff compared to going 35 spline shafts not included for axle shafts i was going to run yukon shafts clearance for 50 degree steering from branik and either yukon or bobby longs joints

I have a 40 spline front 60 inner and outer with CTMs very solid. I choose to run a bastard 1310/1350 slip on the front shaft as my fuse. But my drive shaft really can't do any collateral damage if it breaks. Easy fix, just unbolt and slid on a new one at the easy end.

i used to think that the ds was a good fuse until i took out an oil pan

The 300 in factory form I can agree with being a weak spot, but 9"s can be built up pretty nicely to hold up to abuse. Aftermarket case and 35 spline locker/shafts, good to go.

for the front (or rear) I think 35 spline axle would be good enough in the 40" tire range without becoming a weak point

not worried about the 9" when it goes boom dana 70 will go in and the dana 300 an atlas will bolt right in as a decent replacement i would buy one now but i don't know what i want for gear ratio all i have ever wheeled is stock tcase gearing and shitty axle gearing so i will see what the 4 to 1 is like and make my desion from there

The stock 30 spline outers like to do that. I haven't personally seen 35 spline outers break the long way and take out the spindle like the 30's do.

this is what i am trying to prevent

 

Ok i'm just a noob, but my axles are getting built for 40 spline rears since the rear axle sees a LOT of weight and traction during hill climbs.

The fronts i have gone 40 spline inners, CTM's and 35 spline outers.

Why? If years of wheeling yota gear has taught me anything, it's that no matter how beef yer shit is, something will eventually break. I want a fuse that is easy and inexpensive to get at and replace, and cheap enough to be able to carry spares.

I'm hoping (without having a huge amount of experience in this gear) that the 35 spline outers will bust first without taking out the u joints.

 

will bust first without taking out the u joints.

And hopefully not balloon your spindles.

 

I have a 40 spline front 60 inner and outer with CTMs very solid. I choose to run a bastard 1310/1350 slip on the front shaft as my fuse. But my drive shaft really can't do any collateral damage if it breaks. Easy fix, just unbolt and slid on a new one at the easy end.

 

i'm running a LQ4 6.0 (dyno proven 295 to the ground), th350, dana 300 (big shafts front and rear, stock gears) 60 front, 14 rear with 5.13's on 39 krawlers.

in the 60 i'm running 35 spline superior's evolution 4340 inner and outer shafts, CTM u-joints, welded carrier and yukon drive flanges. in the years time since it's been completed, i've been pretty hard on the buggy at times and so far the only thing that has given way is a ring and pinion. the ring and pinion was in the axle when i bought it and i don't know how long or what kind of life it had before hand. it had a good pattern so i ran it.

40 spline stuff would be nice but i'd save it to spend the money on an atlas