I certainly would not say the stock D30 is crap. It's a good solid axle, however, there are limits to a what a stock D30 can do. Can you get away with running 37s on a stock D30 and going to Moab? You can for a while but eventually something’s gonna give.

35s on a stock D30? After you add gussets, if you are carful with the skinny pedal off-road, you may be fine for many years and you might not. If you are not so skilled at off-road driving and don't like surprises on the trail then go ahead and build up your D30. A built D30 is formidable with 35s and should be near bulletproof.

 

near bulletproof sounds good enough for me

 

i dont think you should be worrying about 35s on a D30. there are alot more threads on the d30 and 37s. the jk just looks right on 35s. just gusset it regear and call it a day man.

 

d30 it is then

 

One more thing to consider when building an axle is what is the week point. On a stock D30 the week point after gusseting it is the shafts & U Joints. If you add aftermarket shafts the week point becomes the spider gears / carrier. Add a locker and the week point becomes the R&P. Add higher gearing for 35s and the higher gearing combined with the thinner teeth of the R&P means the R&P are even more vulnerable. Breaking an R&P is an expensive fix.

On a built D30 be careful how high you go on the gearing. I would be careful going over 4.88.

 

I feel like i hear more and more that ring and pinions break with 5.13 in a d30 so to have to do that work and buy another ring and pinion again its worth just upgrading that axle and keeping 4.10s i feel like

 

i think i'll go with the best of both worlds "4.88" this way it is a fairly high ratio and still decent on the highway.

 

what are your thoughts on locked axles breaking less than open. my though is that your hp is devided equaly into four. so to keep it simple with 100hp you have 25 at each wheel when locked. with open you still get 50 at each axle but when stuck or spinning one wheel you have the full 50 going to one side and when traction changes either turning or going from mud to dirt the spider gears transfer that 50 over to the other side so quickly, BANG something breaks.

 

Great Question.

You have part of the equation right and part is not quite right.

Yes, most axles break from too much skinny pedal. You try and get over an obstacle and one tire starts to spin and then when that spinning tire suddenly regains traction so much force is exerted on that one shaft it breaks. Locking the axles keeps any one tire from spinning as much so the chance of breaking axles is lower.

However, the idea that lockers distribute the applied force equally, 25 ft/lbs per axle as you say is not correct. Open diffs try and distribute the applied torque equally. Lets simplify and take the example of 2WD where one tire is on ice and the other tire is not. In an open diff the tire on the ice has near 0 ft/lbs of torque as the applied force cannot build up due and move the vehicle due to the spinning wheel. The opposite wheel, even though it’s not on ice also has near 0 ft/lbs of torque applied because the open diff is keeping the force at both wheels equal. So you don’t move and sit there and spin.

A locker does the opposite of an open diff. Instead of distributing the applied force equally like and open diff it concentrates the applied force at the axle with the most traction. In the ice example, if the applied force is 100 ft/lbs then the tire on the ice has near 0 ft/lbs of applied force and the tire not on the ice has all 100 ft/lbs of torque. In the locked case the vehicle will move. Lockers are useful in unequal traction scenarios like ice and lifted tires because they concentrate the applied force at the wheel with the most traction, transferring the force away from tires with little or no traction to those tires with traction.

Lockers can transfer up to 100% of the applied force to a specific tire. Limited slip diffs, depending on the type, can transfer between 50 and 75% of the applied force to a specific tire. Open diffs do not transfer any force to the opposite tire.

So back to the question at hand, will a locker reduce the risk of breakage? In some respects Lockers will decrease the chance of breaking stuff from skinny pedal + spinning tires scenario. On the other hand Lockers vastly increase the stress on the drive train and the forces applied to specific wheels way beyond open diffs increasing the chance of breakage in situations where one wheel has the majority of the traction thus increasing the risk of breakage. Again it comes back to the driver. If you do something stupid you can break an locked diff as easily as you can break and open diff.

 

Well, this statement says alot, sounds good to me
im building up my d30 as well to run 35's and because of this guy i've got no worries so take it easy on the gas pedal, drive smart and you'll be OK