U-Joint Selection

[nwoods]

I have a Rubicon LJ (Unlimited TJ), with stock D44's and 4:10 gearing on 35" tires. Perhaps I am wrong on this, but I think I'd prefer to have a U-joint fail on the trail than my drive shafts, axles, or diff's. So, with that said, what U-joint do you guys recommend? I am NOT looking for the strongest burliest u-joint in the world. Where do you get yours?

Also, what size sacrificial socket is the 'right' size for driving out the caps when used as a punch?

Along the same line of thought, what about yokes? That seems like something I definitely do NOT want to fail. What replacement part mfr for yokes do you recommend I keep on hand should something undesirable happen?

What else should I be asking or thinking about?

[mrchips]

I am not sure what size u-joints the Rubi takes, but I have a couple buddy's that have blown out the lockers on the Rubi, running 35" tires. That would be my first worry. The Dana 44's are not a stout axle, and it seems bending tubes and breaking lockers , running 35's or larger tires is more, of a weak point than breaking a U-joint. My 2 cents of what I have seen over the last 3 years, that I have had my LJ.

[nwoods]

I agree. I have had many people caution me, wisely, about the stock locker vulnerability. I am pretty gentle on the rig. But its because of this vunerablity that i want the "fuse" in the system to be the u-joint, not in the diff!

However, if I do break a locker, what all will I need to affect a trail repair sufficient to get moving again? Which component tends to fail? How much diff fluid will I need? What about sealant for the diff cover? I personally have never taken a diff apart, but I have seen them disassembled.

[NAILER341]

i have always been a fan of spicer u joints.
i have since upgraded tot he CTM's in my 30, but it is the same joint you use on your 44.

if i weren't running the ctm's i would undoubtedly be using spicer.

[inVERt'D]

Using the u-joint as the "fuse" sounds good in principle, but a broken u-joint will very easily result in a broken or tweaked yoke. Your Rubicon came with Dana Spicer 760x u-joints, which are an stronger upgrade to (and swapable with) 297s. Alloy USA makes a reasonably inexpensive forged steel alloy version I've seen on eBay for under $40 ea.; "X-Joint" p/n 11500.

[nwoods]

Awesome, thanks for the info. Is there a better idea out there regarding the weakest link as the "optimum" point of failure?

[NAILER341]

the warn small hub conversion was cool for a bit on my dana 30, but after a while you get tired of those. it seems any failure can transmit some heavy backlash yto your locker.

i have learned that after 2 hub failures you can expect the hardened axle to break, and that will likely damage the locker.

i am now running prototype drive flanges on my dana 30. i have since put the 30 in the position where i am quite sure it would have broken the small hubs, but was able to back off and continue down the trail.

i had the mindset that the "fuse" or weak link would be nice. i have since changed my position to making it so nothing breaks. i might change my mind when i have a big catastrophic failure, but having been through a locker, and alloy axles as well as numerous hubs.... i'm not sure what that point is any more

[curtis]

Erik do you use a unit bearing with the drive flanges?

[aw12345]

For U joints stick with spicer U joints best quality stock U joints. Seems in the front the Yokes on the stock axle shafts are more of a weak link than the U joints. Breakage is often due to the axle yoke deforming and opening up instead of the U joint it self failing. I ttweaked mine with a puny 4 cyl, Took about 2 wheeling trips with 35" tires to take care of that

[NAILER341]

Erik do you use a unit bearing with the drive flanges?

it is the warn small hub conversion with a prototype drive flange consisting of the "hat" and a slug.
the "hat" replaces the small warn hub, and the slug has teeth to match both the inside of the hat and the outer axle shaft splines. it is a very positive engagement.

[inVERt'D]

For U joints stick with spicer U joints best quality stock U joints. Seems in the front the Yokes on the stock axle shafts are more of a weak link than the U joints. Breakage is often due to the axle yoke deforming and opening up instead of the U joint it self failing. I ttweaked mine with a puny 4 cyl, Took about 2 wheeling trips with 35" tires to take care of that

You're still using a D30, right Art?

[mrchips]

As for the diff repair, carry 2 QTS oil, and a lube-locker/or RTV gasket,material. Pull the cover ASAP if you think there is a problem, or feel clunking in the rear end, and clean out the oil with any pieces of metal. You at least want to save the ring& pinion, from any major damage. Fill with oil again and try to drive out without using the locker. This is what we did to one of our members LJ. Was able to drive home 200 miles with no problem, then had to rebuild the rear end.

[curtis]

it is the warn small hub conversion with a prototype drive flange consisting of the "hat" and a slug.
the "hat" replaces the small warn hub, and the slug has teeth to match both the inside of the hat and the outer axle shaft splines. it is a very positive engagement.

Sounds like a good idea. Never did like changing a hub on the trail. Would whether change a UB on the trail than a hub.

[Mitch]

Nathan,

Let me jump in with an observation. I've broken 2 30spline rear axles that were probly due to the weak d35 axle tubes being bent or flexing, but if you break an axle at the splines and drop hardened steel into your diff you are screwed. Total tear down and debris removal. If you break it clean in the middle you might be ok to limp off the trail (non C-Clip).

But If you are gonna carry front axles, have them assembled with u-joint installed, ready to drop in. I've seen Chuck (CJ) blow a u-joint and take out the yoke, and in 20 minutes while the rest ate lunch, remove the tire, brakes, and slide the axle out and slide in another one and be continue on.

As far as the Rubi lockers, Max has wheeled everywhere in his Rubi for a several years before a spider gear failure in the locker, and if you know him, he has gone everywhere that it's possible to put a Jeep!It's how you massage that skinny pedal!

My meager .02

Mitch

[kirkandsylvia]

I'd have to agree with Mitch (great88), I have a stock D30 in front and a stock D35 w/ locker in rear, and I have had great luck so far, and I have put my XJ in some pretty nasty stuff. It's all about the ease of the gas pedal. Granted, I would, if the pockets were deep enough, upgrade to D44's in my XJ like my 76' has, but why change something if it ain't broke...yet.
Replacing axle parts on the trail isn't fun, but it's also not too terribly difficult either. There are enough jeepers on the trail on any good weekend that would assist.
In answer to the sacrificial socket, I believe the size is a 9/16".