Any info or advice on modifying a rear driveshaft double cardan joint for a little more flexibility?

[Gollywomper]

Quick search shows 1310 cv max angle is 28* and a 1350 at 32*.
Increasing from 32 to 42 is a big improvement if one wants to drop the coin.

 

[Gollywomper]

Not much downside to a center strap. Pretty common for TJs with 12" shocks. The only time it will limit performance vs a pricey high angle driveshaft is if you get the belly hung up just enough that 1" more of letting your tires move down would get you traction, or if you're jumping it and want as much travel available as possible (but then you'd likely have straps on each corner so you're not busting the caps on your shocks).

With my doubler project it may come into play as I will be loosing around 1.5” of rear DL length. With shocks on the short list I was checking my options. Don’t plan to use one unless needed.

 

[mrblaine]

Quick search shows 1310 cv max angle is 28* and a 1350 at 32*.
Increasing from 32 to 42 is a big improvement if one wants to drop the coin.

That can be a problem if you wheel where you need to always have a spare rear driveshaft.

 

[Jerry Bransford]

Quick search shows 1310 cv max angle is 28* and a 1350 at 32*.
Increasing from 32 to 42 is a big improvement if one wants to drop the coin.

There's a lot to this subject, take a look at the Angles section at https://www.offroadxtreme.com/engin...ch-u-joints-and-when-to-look-at-going-bigger/

I retired my 1350 rear CV driveshaft and replaced it with my previous 1330 equivalent. The 1350 shaft's CV joint sounded like a machine gun when my rear axle was fully drooped.

 

[Gollywomper]

That can be a problem if you wheel where you need to always have a spare rear driveshaft.

I don’t plan on using one unless it is a necessity. I expect to run a limit strap, as long as I have suitable down travel available in the standard shaft I will not be replacing it. Much easier to swap out a common shaft to get yourself or somebody off the trail.

 

[jjvw]

As long as the shaft allows for reasonable droop and the strap does not prevent full articulation is there really a downside to using a strap?

If there is a meaningful downside to a center strap, I don't recognize it on mine. I've been turtled several times and maybe no strap would have helped. I don't know. Except that the Jeep has spun like a merry go round on a rock, so maybe not. But I like not damaging my driveshaft more than I already do and I'm fine with a $50 fix over the alternative.

 

[Gollywomper]

If there is a meaningful downside to a center strap, I don't recognize it on mine. I've been turtled several times and maybe no strap would have helped. I don't know. Except that the Jeep has spun like a merry go round on a rock, so maybe not. But I like not damaging my driveshaft more than I already do and I'm fine with a $50 fix over the alternative.

Agreed. When running 12” shocks there’s 2 choices. Limit strap or special DS. Well maybe 3 as the other option is doing nothing and hoping you don’t take out your tcase. In reality with a strap you may loose 1” of droop that probably isn’t going to provide any meaningful traction anyways.

 

[toximus]

4th Option: Wheelbase.

On a LJ you can get 14" of travel, flat belly, and an off the shelf 1350 in the rear:

 

[jjvw]

4th Option: Wheelbase.

On a LJ you can get 14" of travel, flat belly, and an off the shelf 1350 in the rear:

View attachment 256429

After two trips to Moab in a month, I've been coming back to wheelbase as something to think more about in a few years.

 

[kmas0n]

So, check my understanding..
You can have a custom driveshaft made with a 1350 dc joint that can tolerate more angle. The T's are bigger so there's more room in between them meaning the little ball has more room and the drive shaft can accommodate higher misalignment. If you are running light duty axles and transfer case it might be wise to use a 1310 on the pinion flange to have a "fuse" that will fail before anything else, and it's easy to replace the flange u joint if it does fail.
Am I processing this correctly?

 

[Blackjack]

So you can make a 1310 double cardan have more angle but it comes with a couple issues. First is that only shops experienced with custom work will talk to you and that they require diligence in greasing them.

So do do this you will need a 1330 h-yoke, a greaseable centering flange and 2 5-134x ujoints. This requires significant fitting and grinding with a carbide burr on a die grinder. Once everything is fitted balancing the shaft is critical along with a center limit strap as catastrophic failure will occur if allowed to bind as you are at the limit of what all the parts can handle.

 

[toximus]

So, check my understanding..
You can have a custom driveshaft made with a 1350 dc joint that can tolerate more angle. The T's are bigger so there's more room in between them meaning the little ball has more room and the drive shaft can accommodate higher misalignment. If you are running light duty axles and transfer case it might be wise to use a 1310 on the pinion flange to have a "fuse" that will fail before anything else, and it's easy to replace the flange u joint if it does fail.
Am I processing this correctly?

Tom Woods 1310 driveshafts allow more angle than their 1350 driveshafts. 1350 also takes up more length which gives you less effective driveshaft length (resulting in an even higher angle). Also, 1350 driveshafts are heavier robbing more HP.

 

[kmas0n]

Tom Woods 1310 driveshafts allow more angle than their 1350 driveshafts. 1350 also takes up more length which gives you less effective driveshaft length (resulting in an even higher angle). Also, 1350 driveshafts are heavier robbing more HP.

Tox, This is what makes since to me, but this post confused me...

"Quick search shows 1310 cv max angle is 28* and a 1350 at 32*."

Thanks for clarifying.

Also we are on theoretical territory now. It's been established my current driveshaft is within tolerances.

 

[toximus]

Tox, This is what makes since to me, but this post confused me...

"Quick search shows 1310 cv max angle is 28* and a 1350 at 32*."

Thanks for clarifying.

Also we are on theoretical territory now. It's been established my current driveshaft is within tolerances.

Spicer vs Neapco and who's assembling it can also yield slightly different results.

 

[Gollywomper]

Tom Woods 1310 driveshafts allow more angle than their 1350 driveshafts. 1350 also takes up more length which gives you less effective driveshaft length (resulting in an even higher angle). Also, 1350 driveshafts are heavier robbing more HP.

The length of the 1350 CV was my next question. Seems it may be to big/long to be of much value for my extra short shaft.

 

[toximus]

The length of the 1350 CV was my next question. Seems it may be to big/long to be of much value for my extra short shaft.

If you're running the 4.0 I don't see any added value to 1350 joints. You'll just end up spending an extra ~$150 per shaft.

 

[Trevlaw]

If you call and talk to someone at Tom woods, they offer a service to clearance specific parts of the double cardan assembly to get more angle out of a 1310 shaft. Whether that means they use specific parts on it or not I don't know. I had it done on my rear shaft and measured the max angle around 33-35* on it. Wasn't super expensive, I just have to remember to tell them when I get my driveshaft rebuilt every year or so.

 

[Blackjack]

If you're running the 4.0 I don't see any added value to 1350 joints. You'll just end up spending an extra ~$150 per shaft.

Add to that with quality components 1350 stuff is stronger than the Dana 44 pinion shaft. I would much rather repair a driveline over a new ring and pinion.

 

[Trevlaw]

Agreed. When running 12” shocks there’s 2 choices. Limit strap or special DS. Well maybe 3 as the other option is doing nothing and hoping you don’t take out your tcase. In reality with a strap you may loose 1” of droop that probably isn’t going to provide any meaningful traction anyways.

Not so cut and dry. I run 12's in the back and don't need any of those things. I've got the shortest factory factory drivetrain though with the 32rh and a 231 SS SYE with a flat belly. I burn through driveshafts every year though, probably could be fixed with putting the pinion inline with the drivetrain or dropping the drivetrain a half inch or so

 

[Gollywomper]

Not so cut and dry. I run 12's in the back and don't need any of those things. I've got the shortest factory factory drivetrain though with the 32rh and a 231 SS SYE with a flat belly. I burn through driveshafts every year though, probably could be fixed with putting the pinion inline with the drivetrain or dropping the drivetrain a half inch or so

Are you running a special clearanced CV?

If you call and talk to someone at Tom woods, they offer a service to clearance specific parts of the double cardan assembly to get more angle out of a 1310 shaft. Whether that means they use specific parts on it or not I don't know. I had it done on my rear shaft and measured the max angle around 33-35* on it. Wasn't super expensive, I just have to remember to tell them when I get my driveshaft rebuilt every year or so.