what U-joint should you go with? And what, exactly, is the job of a U-joint? Well, a U-joint is designed to not only allow the driveshaft to move in its arc without binding, but it is also the weak link.
Most likely your Jeep came factory with a U-joint in your driveshaft. Right away, most folks listen to that little voice saying ‘Bigger is always better’. But before you listen to that voice, take a few things into consideration.
You may think, if your jeep came with 1310 or 1330 U-joint, the next step would be to upgrade to a 1350 U-joint – it is heavier duty and the number is larger than 1310, so it must be the way to go, right?
Your Jeep is composed of many components; many expensive and time-consuming components when it comes to repairs. However, that 1310 U-joint only costs about $15 to replace, and if you have any mechanical skills you can change it while out on the trails.
The 1310 U-joints are typically easier to find when you need a new one as most auto parts stores have them in stock, and when you go off-roading and happen to break a driveshaft or joint, your buddies with similar vehicles will usually have the factory replacement spare.
Okay, so what about the 1350 U-joint? They are bigger and stronger but that means unless you have the set up to accommodate this kind of strength, you may do more harm than good.
Take the same situation from above, on Axle Crusher trail, you and your JK lifted with 35s and stock axles, but instead, you went with the ‘bigger is better’ voice and have 1350 U-joints. The vehicle is working as it did before, but this time it isn't the 1350 U-joint that breaks - it is your stock axle or ring and pinion.
Why? The 1350 U-joint is strong enough that it is no longer your vehicle’s weakest link. Now, your axle or transfer case is the weakest link. And now you are on the trails with a broken axle instead of a broken 1310 U-joint which you could have repaired right there for under $20. Make sense?
If you are still running factory axles or even a slightly stronger upgrade, then staying with the factory-sized 1310 or 1330 U-joint will keep your weakest link at a $15 part replacement vs. that $1000 wallet-sapping repair.
Well, if your vehicle is heavily modified, sporting Dana 60 axles, 40” tires, and you find your time outside is usually spent around boulder infested black or red trails, then you may want to consider 1350 U-joints. How come? Because those other components on your Jeep - axles, tires, etc. - are stronger than the 1350s, so the U-joints then become your weakest link.
Back to the trails, with your JK on 42's, Dana 60s, and 1350 U-joints, and your group decides to take on a trail called "Death Trap" (Scary!)
Your axles are working, the transfer case is sending power and your heart is racing! Then SNAP! 1350 u joints have met their match, but you are perfectly happy to replace the $15.00 part rather than your $2500 Dana 60.
The downside to using the 1350s is they are not as readily available vs. the 1310s. If all of your wheeling buddies have the 1310s, you may have limited options so you might want to carry