Originally Posted by ShutterBug

So is it the axle shaft or the drive shaft? These are two different things.

Assuming you mean axle shaft (since the stock drive shaft has no u joints) - you should also consider upgrading both shafts, not just the u joints.

Originally Posted by larry0071

My opinion is that if you have stock-ish sized tires, replace it with a MOOG, TRW or Dana/Spicer joint and you'll be good to go for many more years.

If you have 35" tires or larger, I would seriously consider just doing a set of Ten Factory alloy shafts (or similar).
Ten Factory JK Dana 30 27 Spline Alloy Shafts/Joints.
https://new.northridge4x4.com/fits/2...front-axle-kit

While I was there and into the fray, I would absolutely consider doing both front axle shaft U-joints at the same time and not just the one that failed. NorthRidge 4x4 has the Dana/Spicer Joints, and I would link them to you, but I don't know what year your JK is. Call NR4x4 and they can send you the seals and joints if you want to just replace your old worn parts.

I would also pop the diff out, scrub out the case, knock out the axle seals and replace with new, and get some fresh new axle lube in there. I'm sure that the seals that are in there have seen better days and tossing in a new set of seals for about $40 could very well prevent you from tearing into this axle again in a few months or years when the leakage begins.

Dana/Spicer OEM Axle Seals:
https://new.northridge4x4.com/fits/2...-tube-oil-seal

Originally Posted by Chuck-The-Ripper

I, on the other hand, would highly discourage you from upgrading your front shafts. If you had something other than a Dana 30 I would agree, but being that you do, it wouldn't be a good idea. You will transfer all the stress that was once on the axle shafts (which are easy to carry spares and easy to change, relatively cheap too) onto the ring and pinion. I would just replace it with a Napa brand u-joint. They're made by spicer.

Originally Posted by lonesometree

Whew! Glad that's done! Only broke one bolt but it took me all day to break it free. Pretty simple job if all goes well. But I always suggest preparing for the unplanned obstacle...

Originally Posted by TreyJK

Do you know the part number for the u joints that you bought? Mine are needing to be replaced soon. Amazon says that some fit and some don't but the reviews are mixed on whether or not they work for the JK.

Originally Posted by sa29560

Believe the spicer part # is 5-760x. Also think the newer model years have a different part #. Hope someone will clarify.