Drive Shaft tech help, please

[21JLURDG]

I'm really confused about using a "yoke" or a "flange" on the axle when choosing a new drive shaft. Also, seems that double-cardan joint is the preferred choice for vehicles with larger tires.

Right now I have the stock drive shafts and I just noticed the lip of the T-case front output is bent. It's a good chance I did that while dropping the front axle for a coil spring swap. So as I'm finishing a swap to a taller 4.5" lift (from current 3.5") I see this as a good time to upgrade to 1350 HD drive shafts. But I don't understand the benefits of choosing to keep the pinion flange or swapping to a 1350 yoke on the axle ends.

Can someone comment on this?

For reference, I have:
2021 JLURD
Teraflex short arm 4.5" w/37s but might eventually go to 40s.

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[JEEP4U]

Double-cardon joints work better at increased drivetrain angles.

However, running short arm 4.5" lift, you will run the caster angle in the negative direction and pinion angle in the positive on a stock axle. That is why utilizing the drop brackets are essential; unless you get a custom made axle.

I recommend Spicer driveshafts.

 

[grimmjeeper]

Double-cardon joints work better at increased drivetrain angles.

However, running short arm 4.5" lift, you will run the caster angle in the negative direction and pinion angle in the positive on a stock axle. That is why utilizing the drop brackets are essential; unless you get a custom made axle.

I recommend Spicer driveshafts.

One option is the double ended double cardan axles. It has a double cardan at both ends to handle the bad pinion angle. Tom Woods (and probably others) sell them. They're not cheap but cheaper than a custom axle.

 

[GATORB8]

I'm really confused about using a "yoke" or a "flange" on the axle when choosing a new drive shaft. Also, seems that double-cardan joint is the preferred choice for vehicles with larger tires.

Right now I have the stock drive shafts and I just noticed the lip of the T-case front output is bent. It's a good chance I did that while dropping the front axle for a coil spring swap. So as I'm finishing a swap to a taller 4.5" lift (from current 3.5") I see this as a good time to upgrade to 1350 HD drive shafts. But I don't understand the benefits of choosing to keep the pinion flange or swapping to a 1350 yoke on the axle ends.

Can someone comment on this?

For reference, I have:
2021 JLURD
Teraflex short arm 4.5" w/37s but might eventually go to 40s.

That's the RZeppa lip you bent, not the T-Case output flange.

For the front, You'll re-yoke the tcase output from a flange for the RZeppa to a yoke for the DC, and you'll likely get a flange style mount on the axle side.

You can impact preload when you swap axle side, so avoiding that end is kind of safer as fall as proper install.

I believe aftermarket rears have to swap the yoke at the rear axle.

 

[grimmjeeper]

That's the RZeppa lip you bent, not the T-Case output flange.

For the front, You'll re-yoke the tcase output from a flange for the RZeppa to a yoke for the DC, and you'll likely get a flange style mount on the axle side.

You can impact preload when you swap axle side, so avoiding that end is kind of safer as fall as proper install.

I believe aftermarket rears have to swap the yoke at the rear axle.

Yep. Front axle had a standard flange for a u-joint yoke. Rear axle has a rzeppa joint yoke that needs to be swapped out. When you do that you need to get the nut tight without crushing the crush sleeve more than it already is. Not rocket science but you do need to pay attention to what you're doing.

The transfer case has rzeppa flanges at either end that need to be swapped out. But those are easy. Just torque to spec on those.

 

[Maverick909]

I am running dbl cardigan rear shaft in my jeep currently with 1350 u-joints. wasnt a big deal at all to replace the yokes on both ends. My shop is less than a mile away from JEReel drive lines. I stopped in and talked to them and they recommended the 1350 with dbl cardigan due to the setup i am running with 37's. also showed me how to correctly measure to make sure the shaft was built to the correct length. Was able to pick it up the next day. Highly recommend them. i went with the yoke style as it tends to be stronger than the flange styles.

 

[21JLURDG]

That's the RZeppa lip you bent, not the T-Case output flange. For the front, You'll re-yoke the tcase output from a flange for the RZeppa to a yoke for the DC, and you'll likely get a flange style mount on the axle side.... I believe aftermarket rears have to swap the yoke at the rear axle.

Yep. Front axle had a standard flange for a u-joint yoke. Rear axle has a rzeppa joint yoke that needs to be swapped out.
The transfer case has rzeppa flanges at either end that need to be swapped out.

Ahhh... So, it's not necessarily what's better but what's good enough and easier. In a nutshell, the goal is to eliminate the Rzeppa and keeping the flange mounts is acceptable.

In summary, what I should expect:
Front DS with T-case output yoke and axle side flange.
Rear DS with T-case output yoke and axle side yoke.

I bumped it up from 3.5" lift to 4.5" with taller coils and installed a front CA drop bracket per Teraflex's suggestion. I know it's not ideal, but swapping to a long CA lift just for another inch was not worth it. And since this is a 4-door, I'm assuming the rear driveshaft angles should be fine.

I don't think I need the complexity of double-cardan joints on both ends of each DS. I'm not even sure I need any double-cardan, but I'm going with conventional wisdom and adding one to each DS to avoid future regrets.

Now I need to decide on what DS I need with possible future upgrades to 40s with 310 hp/510 ft-lb through a 4:1 low range. These are expensive toys.

 

[grimmjeeper]

Ahhh... So, it's not necessarily what's better but what's good enough and easier. In a nutshell, the goal is to eliminate the Rzeppa and keeping the flange mounts is acceptable.

In summary, what I should expect:
Front DS with T-case output yoke and axle side flange.
Rear DS with T-case output yoke and axle side yoke.

I bumped it up from 3.5" lift to 4.5" with taller coils and installed a front CA drop bracket per Teraflex's suggestion. I know it's not ideal, but swapping to a long CA lift just for another inch was not worth it. And since this is a 4-door, I'm assuming the rear driveshaft angles should be fine.

I don't think I need the complexity of double-cardan joints on both ends of each DS. I'm not even sure I need any double-cardan, but I'm going with conventional wisdom and adding one to each DS to avoid future regrets.

Now I need to decide on what DS I need with possible future upgrades to 40s with 310 hp/510 ft-lb through a 4:1 low range. These are expensive toys.

There's nothing wrong with RZeppa joints. But the ones in the factory shaft aren't strong. And once you start flexing too much you over extend them. The aftermarket uses double cardan because they work very well and are easy to service.

I went with Tom Woods 1350 shafts front and rear. They're full of beefy goodness. They ship with all the correct flanges you need.

Plenty of other shops like Adams Driveshafts and others will also provide what you need if you go a different route.

You can probably find some with 1410 joints but those are spendy and maybe overkill. Just don't go budget with 1310s.

 

[21JLURDG]

After your inputs and discussing it with Adams Driveshaft, I ordered: double-cardan 1350 w/1.5" stubs

Front: 2 1/8" x 0.180 tube
Rear: 2 5/8" x 0.156 tube

These should provide a nice upgrade from stock and from compression/torque-limited standard engines.

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