PEAK PUTTERS

For those in the know, which would not be me, What's the deal?

Are JK D30's that much different than a TJ/YJ/XJ? I have a friend that blew up his R&P on his JK D30. I know Toby has had problems with his first non-Rubi JK, even after some strengthening mods. And now, I hear rumors of another R&P failure on a Putter's JK.

Yet, others seem to be running one without problems. I think.

Do you have one? What upgrades have you done to it? Did it break? Why or why not?

Am I sitting on a ticking time bomb with mine? Still open and stock shafts.
Just trying to get a grasp on a cost effective plan for a front end upgrade this spring.

Anyone? I have thick internet skin so bashing is allowed. Let's have it!

Well, I have a theory:

JK D30 Ring and Pinion sets typically break because a u-joint gives up while under a load. The resultant shock load travels back through the axle shaft, which has become a torsion spring and strips the teeth off of the gears. Pretty common knowledge.

My part is that I think that the JK's built in traction control somehow exacerbates the problem by applying braking force to try and slow down a spinning wheel. . .that can break the u-joint and start the chain of events outlined above. JK Axles are also wider and probably have more flex issues than any of the older housings. None of that helps. The really weird thing is that people don't report a lot of issues with 760X/297X u-joints up to 35" tires. I absolutely ABUSED them in my CJ with 35" tires and a V8 with zero failures. Now, the JK comes along and blows that theory. . .wonder why?

As to your question, the biggest variable that you have to consider about your time bomb, in my opinion, is driving style. Since you are wearing your interwebz armor, I'll be quick to point out that you are rather timid or cautious behind the wheel. That is NOT an insult. In this case, it is a huge compliment. Your front end will probably last a good long while. I would certainly keep a set of spares on board (I do), but the second you consider beefing up the D30 with alloy axles, trusses and such, I'd take a hard look at an HP44 from our friends at Ford along with the proper bracket kit and a new set of wheels (for a different bolt pattern). You have the same u-joint, but you would be less likely to rip the ears off of the shafts, the inner shafts are bigger, and the differential set up is quite a bit stronger.

Now, If I were you, I would just stay out of the rocks and keep a spare set of shafts on board. At the MOST extreme, you could toss in an XJ front end geared to match for the HP diff, but the gear set up would be cost prohibitive. If you decide to add a locker and grow a huge right foot, then an upgrade would be in order. . .If you are just throwing in a locker, I'd keep the 30 and see how it works out. If I remember correctly, you are running 4.88 gears. That makes the locker equation a little more marginal because of the small pinion gear.

Every other Jeep site in the World would probably tell you to either throw a couple of grand at your D30 or "Go 60s and forget about it". . .but they don't wheel like we wheel and, they spend too much time on the internet and not enough out on the trail. It is SUPER easy to spend someone else's money.

How much heavier is a JK than a TJ? Could be another part of it, especially with the big 2 doors.

There isn't much else to add after Jimmy's narrative above, he pretty much nailed it on every account. I have indeed broken a couple of D30's in various ways (including the original Minivan), but I will be the first to admit that I was being STUPID when they broke and easily could have avoided the damage entirely. I'm also "less aggressive" behind the wheel, as Jimmy has noted about you, and I firmly believe that driving smarter rather than harder will ultimately get you further, and more importantly, back home Keep the 30, drive like you own it rather than like you stole it, and save your money for fuel so you can wheel more often.

another thing is didnt lance just recently like last 3 or 4 months get that front end geared?

if so aftermarket gears often lack the strength and quality of a factory set and i have seen a few "experienced" gear installers that i wouldnt want in my axles not saying that is his case but setup and a solid pinion spacer saves a lot of headaches

Lance is but one sparrow in the hurricane of broken JK front ends. . .factory parts, aftermarket parts, open, locked, etc. . .

very true, the only JK person i personaly knew was with 37's and open front end with the 6 speed non unlimited wheeled in PA with them so muddy rooty areas and he was not a nice to it and had zero front end issues

Don't they have D44s in them now? I just thought of that. . .

my quick googlefoo says from 2007 up they got d44 variant with a different pinion than normal d44 on rubi's

Well, some came with D30s for sure. I've seen it in person. They are a "short pinion" D30. You can even get 5.13 gears for them. I think that might be what Lance had/has. . .

Lance??

I agree with Jim's theory on the JK R&P issues.

I'll think you'll be fine with the D30 in your TJ. I've broken a couple of u-joints in the front of my Comanche over the years... but those were the smaller 260 joints. One of the breaks I was doing something stupid and the other one was a brand new off-brand u-joint that broke, I learned to always buy Spicer. One of them also broke the axle at the same time.. I think the joint blew first and the shock of that caused the axle to break, like Jim described. I've since swapped in stock axles with new larger 760 u-joints and haven't had any problems. That's with 4.88's and an ARB. I usually carry spare axles too, they are pretty easy to swap out on the trail. From what I've read the stock axle will usually break before the 760 joint.. not sure how true that is. Also have stock D30 axles in the Cherokee on 37's.. only plan to wheel it in the snow but so far they've held up

My '04 TJ has the factory Dana 30 for the last 5 years with upgraded shafts and U joints, aftermarket 4.56 gears, running 33" and now 35" tires, and an ARB with zero issues so far. That being said I always bring my spare stock front shafts all assembled and ready to go if I break the shafts up front. I'd say run the D30.

Don't know why the JK's are having problems with the D30 up front since the JK housings are much stronger along with the shafts and gears compared to a TJ D30. Probably due what other's said in the earlier posts.

Can't one just turn off or disable the traction control in a JK to take away some of the problem? I know I would.

Thanx for all the info guys.

Looks like for now, I'll be keeping the D30 where it is. Looking for a set of spare shafts.


Also, for some reason, I have zero wobbling/shaking issues with combo of arms, springs, and a 3/4" spacer I have in it right now. Hands off the wheel and straight, true, and smooth. I know how finicky these things are, and I'm paranoid I'll get the shakes if I go swapping stuff around.

TJDave wrote:

Also, for some reason, I have zero wobbling/shaking issues with combo of arms, springs, and a 3/4" spacer I have in it right now. Hands off the wheel and straight, true, and smooth. I know how finicky these things are, and I'm paranoid I'll get the shakes if I go swapping stuff around.

And now you went and said [typed] it outloud. :shakes head:

TJDave wrote:Also, for some reason, I have zero wobbling/shaking issues with combo of arms, springs, and a 3/4" spacer I have in it right now. Hands off the wheel and straight, true, and smooth. I know how finicky these things are, and I'm paranoid I'll get the shakes if I go swapping stuff around.

You shoulda come on the last run. I got plenty of wobbles and shakes to spare now....

Ha! I did go and say it, didn't I?

Life has been kind of crazy lately and I have not been able to go on the last few runs.

But, hoping to not fall into the "you can't break it if you don't wheel it" crowd.

Yeah, I went there too!

TJDave wrote:Ha! I did go and say it, didn't I?

Life has been kind of crazy lately and I have not been able to go on the last few runs.

But, hoping to not fall into the "you can't break it if you don't wheel it" crowd.

Yeah, I went there too!

So, you wanna go wheelin?

OldGreen wrote:
So, you wanna go wheelin?

Always. The "wanna" part is never an issue.

OldGreen wrote:Well, some came with D30s for sure. I've seen it in person. They are a "short pinion" D30. You can even get 5.13 gears for them. I think that might be what Lance had/has. . .

Lance??

Correct Jimmy, 5.13s and open... Definitely bit the R&P, but we threw a cap on the u-joint too, and stuffed another on before limping home.

Next go around (the cheap way out) new R & P (Yukons - same as before) but on the Eaton I purchased earlier. Hope to be whole again tomorrow afternoon/evening.

I figure this should get me through the snow season, and hopefully I'll either win the lotto or save enough (odds are better on the first) to get a 44. ProRock would be desired, but if that can't be had I'd settle for a JK Rubi 44 and just gear it, maybe look at sleeving, trussing etc before it gets under Julia....