Interview with Jim Reel at Trail Hero
Kevin and Brittany are back at Trail Hero, talking with Jim from J.E. Reel Driveline at Sand Hollow State Park, Utah. Today, we’re talking about drive lines, drive shafts, which are a bit of a mystery to most off roaders they talk to.
Watch the Trail Hero Jim Reel Interview Video
With the front and rear drive shafts, Jim gets a lot of input from people, along with a lot of reasons why they are usually left with more unanswered questions.
Kevin has had his time researching and fact finding too, and he still has not not have much in the way of answers. So, they are starting with the basics, as Jim walks us through…
Drive shafts step by step.
Listen, most people want to go with a 13/10 because it’s cheaper. But, lets start out with what a 13/10 is.
Now, the kind of joints are on there from the factory, with a Rzeppa ball and cage CV type drive line, works well on the smoothness on road. However, when you start getting bunch of angles and twists, they give up pretty easily.
The first thing most do to is lift their Jeep. That puts more angle and strain on that CV joint that is made for smooth roads, for comfort.
This may be okay for private service roads and dirt roads. But, the minute you go with heavy wheels, beadlocks, 35s,37s and a lift, what’s the first thing to go? The drive line, which breaks pretty easily. This is why…
We’re talking about drive lines, drive shafts, first.
So, when you put wheels and big tires on a Jeep, the first thing that goes is the front drive shaft.
Imagine a CJ7… you have a 31-inch tire, it’s on a 13/10 U-joint, and you’re running down some washes and some mild wheeling. Now look at your JK or JL 4-door today. It’s twice the weight. And the 13/50 is a 3/4 ton-sized shaft, there’s a U-joint.
If you stop to think about the weight difference, your tires, your lower gears and the amount of torque you’re adding, fully loaded, that Jeep is probably now the weight of a 3/4 ton truck. We’re talking about with with your winch, your tires, your bumpers, heavy axles and your tools. As you can imagine, this can get pretty heavy. So you really need that extra strength.
The other thing is, your 13/50 will go 32 degrees, where the 13/10 goes 26 degrees.So the U-Joint will have movement, an offset between the two joints.
So, when you upgrade, it’s a bit tricky.
Because, the rear normally takes more torque load and shock load than the front, so you break that for a different reason. But the front one, that most people don’t think about, is the engine in a JK for example, 7 through 11, is in at 6 degrees, down in the back and up in the front.
Thinking About Your Drive Lines
Now, when you budget in a lift and tires and wheels, you also have to think about drive lines. You are trying to buy drive shafts, thinking about what you put in front, and what you put in the rear, as yo may be thinking of going with a 35 or 37-inch tire, since that’s the most common size these days. If you only want to go up to 35s or you only want to go up to 37s, a 35 is really the absolute limit, for a 13/10.
37s will break them easily. A 13/10 U-joint is basically a passenger vehicle U-joint, in a ’63 Falcon. Put that into perspective with your vehicle size and your tire size, and all of that rotational mass, which is really important to consider. It really depends on your rig as well, in terms of how light your vehicle is.
Now, for Toyota owners…
When we’re talking something like Toyotas, something that’s lighter, you can get away with less U-joint. However, you always have to remember, that bigger tire and lower gears, are applying torque to that joint, and shock load when you bounce it off a rock and come down and flip the throttle, There are all these things to consider, even if it’s a light vehicle.
So when you hear a recommendation for a 13/50 front 13/50 rear to someone, there is apprehension, as the internet said you need a 13/10. And the price difference? You may think you want the bigger, stronger one? But bigger shaft is around $200 more, for a drive line. And everyone has a budget to stick to.
At the same time, if you break something on a trail, what is that going to cost you? Perhaps a lot more. If a 30/10 goes 26 degrees of articulation, and a 13/50 goes 32, you’ve paid for longer shocks and a lift kit to get all this articulation, but you can’t use it because you’re breaking your drive line, or your limit strapping. You’ve built a really great Jeep, now go enjoy it, but you need 13/50.
Now, there’s a lot to consider, when you’re upgrading your Jeep or your Toyota, your Nissan or whatever it is, that you will take off road. But it’s all something to consider as well. And there’s so much to this, than what we’ve just discussed. We could be here for hours, with the different makes and applications when talking about upgrades.
The big idea is, don’t let yourself get overwhelmed and make the wrong decision, going all out, or not going far enough.