Some updates/questions on my driveshaft failure

[JeepOfTheseus]

I hate to see this
When you replace it (and any competent shop can repair that crossmember) you should run a carrier bearing spacer

I was running the RockJock spacer. If it’s fixable, I’d put it back in.

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[JeepOfTheseus]

Good news is I got a new 1350 shaft put in. I decided to stick with a single piece due to the bent/damaged crossmember.

It does seem like vibrations are gone/non-existent up to ~75mph, didn't go much faster than that yet. However, I swear there is a slight groaning under acceleration at times, especially from a stop to ~10-20mph. I can't get a great sense of what that is from Google...seems like anything from bad ring/pinion gears (which were fine before, and shouldn't have been damaged) or wrong pinion nut torque/play in the yoke (which shouldn't have been removed/touched anyways) or worn u-joints (they are brand new).

I actually had groaning in the previous one, but that was fixed after getting a new pinion bearing kit put in (because I probably got the pinion nut torque wrong at the time).

 

[Josh00333]

Have you put the truck up on stands so the rear wheels are 100% free?? Then you can inspect it Max flex and see what if anything is going on with the driveshaft. Is the new one longer?

 

[JeepOfTheseus]

Have you put the truck up on stands so the rear wheels are 100% free?? Then you can inspect it Max flex and see what if anything is going on with the driveshaft. Is the new one longer?

Not yet. Was actually planning to. I think the new one is nearly 1” longer.

 

[Blade1668]

Ryan,
It seems like you really need to check or take it to a good driveline shop, and have it checked from T-case to the axle shafts. A full inspection of R&P. I had to shorten a custom built drive shaft (XJ) after I got it. That was made after installing SYE with a substantial lift, flex that was measured afterwards and ordered. A good speed shop can find or figure out a problem. The driveline shop that shortened mine was a speed shop and made drive shafts too. I would have went there first if I had known. Not that a JT or JL should have axle wrap but it might be something off on control arms swap bar ect??? Especially after dropping out a driveline. Me taking a SWAG it's probably in the axle or the above.
FYI, to all I've not heard of bad service from Adam's or Tom Woods drive shafts. Note: I did read that Adam's squared you away on it.

A slight tangent.... axle droop doesn't really help except for RTI ramps if the tire is setting on the ground without any down force it's not doing squat. A locked axle(s) will. IMHO. Damn I still need to get a rear axle limit strap.

 

[JeepOfTheseus]

Ryan,
It seems like you really need to check or take it to a good driveline shop, and have it checked from T-case to the axle shafts. A full inspection of R&P. I had to shorten a custom built drive shaft (XJ) after I got it. That was made after installing SYE with a substantial lift, flex that was measured afterwards and ordered. A good speed shop can find or figure out a problem. The driveline shop that shortened mine was a speed shop and made drive shafts too. I would have went there first if I had known. Not that a JT or JL should have axle wrap but it might be something off on control arms swap bar ect??? Especially after dropping out a driveline. Me taking a SWAG it's probably in the axle or the above.
FYI, to all I've not heard of bad service from Adam's or Tom Woods drive shafts. Note: I did read that Adam's squared you away on it.

A slight tangent.... axle droop doesn't really help except for RTI ramps if the tire is setting on the ground without any down force it's not doing squat. A locked axle(s) will. IMHO. Damn I still need to get a rear axle limit strap.

Any particular things to look for? The control arms are fairly new Teraflex Alpines. I can double check the torque on everything, but it seems solid: no creaking or clunking (things have been great since replacing the Core 4x4 stuff).

I expected the shops involved to know what they are doing. TBH I don’t really know of any other options around me.

 

[Blade1668]

Any particular things to look for? The control arms are fairly new Teraflex Alpines. I can double check the torque on everything, but it seems solid: no creaking or clunking (things have been great since replacing the Core 4x4 stuff).

I expected the shops involved to know what they are doing. TBH I don’t really know of any other options around me.

Some kind of damage like dents, bent, ect. Length of the control arms if one is set different length "upper to upper"/ lower to lower" same. Track bar or mount might be damaged. If not there check of the pinion being in spec. If you jack the tires off the ground and put in neutral try turning drive shaft and see how "clunking or side play in pinion or forward and back", then check by turning a wheel to see how much movement before turning the drive shaft (other wheel needs to be on ground or held in place) or it should turn the opposite direction. Unless you have a locker, "I didn't notice you posting on having one".
I'd guess the axle took somewhat of a bang when the drive shaft hit the ground, especially since you was moving along. Hopefully this is a few things you can check and get everything going good. Best of luck on this. There is definitely more experienced one's here than I, that know more.

 

[Blade1668]

I just re-read this, you have the rear yoke pointed straight at the double cardigan joint? Is that when setting on the ground as loaded when driving? If not the drive line may be binding slightly or out of phase when loading or unloading "acceleration and deceleration". Also u-joints need to have some rotational motion of the bearing caps too. And some could be from the slip shaft in drive shaft. My LJ has a "ting sound some times" I dented it and lost a balance weight off of it. My driveway is a mild rock garden especially when it rains.

 

[JeepOfTheseus]

I just re-read this, you have the rear yoke pointed straight at the double cardigan joint? Is that when setting on the ground as loaded when driving? If not the drive line may be binding slightly or out of phase when loading or unloading "acceleration and deceleration". Also u-joints need to have some rotational motion of the bearing caps too. And some could be from the slip shaft in drive shaft. My LJ has a "ting sound some times" I dented it and lost a balance weight off of it. My driveway is a mild rock garden especially when it rains.

Yoke is nearly straight while sitting on the ground. Maybe a couple degrees off. I’ll get the measurement tomorrow.

It’s one thing I don’t get about double cardan setups: if it has to be straight, then won’t you always inevitably run into binding? Even having passengers in the rear or not would change it…

 

[Blade1668]

Yoke is nearly straight while sitting on the ground. Maybe a couple degrees off. I’ll get the measurement tomorrow.

It’s one thing I don’t get about double cardan setups: if it has to be straight, then won’t you always inevitably run into binding? Even having passengers in the rear or not would change it…

Off the top of my head I don't remember what the recommended angle for that setup is. On leaf sprung vehicles the pinion is to angle down some since under load it rotates up some.

 

[JTPatriot]

Needed to jump back in about pinion angle.

I earlier stated that the pinion should be pointed up. That is wrong, it should be pointed down to get the 2-3 degrees of difference between the pinion and the driveshaft so as on acceleration as the pinion rises from rotation it does not cause issues.

Sorry for the incorrect info earlier. I just reread what I had posted and wanted to correct it.

 

[WILDHOBO]

Yep, bolt was removed and nut can still be used. As for correcting…that’s what I’m hoping.

As for drooping, I didn’t even hit a bump. Only thing that caused it was I sped up to pass someone.

If you want two piece, and still want to be able to handle a lift and have a stronger shaft, try the Dana spicer 1350 heavy duty. I’ve been running it for ages. It’s 3” od steel, good for up to a 6” lift, and is completely bolt on.

 

[JeepOfTheseus]

If you want two piece, and still want to be able to handle a lift and have a stronger shaft, try the Dana spicer 1350 heavy duty. I’ve been running it for ages. It’s 3” od steel, good for up to a 6” lift, and is completely bolt on.

I wish I realized they had an option. Woulda saved me all this mess and headache.

Needed to jump back in about pinion angle.

I earlier stated that the pinion should be pointed up. That is wrong, it should be pointed down to get the 2-3 degrees of difference between the pinion and the driveshaft so as on acceleration as the pinion rises from rotation it does not cause issues.

Sorry for the incorrect info earlier. I just reread what I had posted and wanted to correct it.

Yea I think that’s why it’s a couple degrees off. Still wondering what this means if it’s loaded down…

 

[WILDHOBO]

I wish I realized they had an option. Woulda saved me all this mess and headache.



Yea I think that’s why it’s a couple degrees off. Still wondering what this means if it’s loaded down…

I’m just glad your damage wasn’t horrific. You could still go that route now.

 

[JeepOfTheseus]

Here’s the pinion and driveshaft angles sitting in my driveway, only about .5 degrees off.

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