wayoflife

i guess my point was that it's not referred to as a "single cardin" - just a "u-joint" or, a "cardin joint".

rterry

mine did they same thing going down the hwy about 60 all of a sudden sounded like someething was coming through the floor of the jeep, pulled over and the front drive shaft had broke loose, i have a 6 inch lift and running 37s, well i turn it over to my insurance and they paid for a new transfer case, my 4 wheel dr shop said i could get a atlas 2 for the price of a new mopar transfer case, and thats what i did...
just something to think about....

Ryanc

"there is no such thing as a "single cardin" - that would just be a u-joint and, you cannot make it angled "pretty damn perfectly" up front without causing your axle to have negative caster and that's a bad thing"

1. yes it can be called a single cardan, 2. you can get your pinion and driveshaft in the same plane. I will not have negative caster.

regarding rzeppa joints, they are really strong but, they are not serviceable and expensive to replace. in fact, if you have a blown cv boot and or joint, you will need to replace your entire driveshaft as there is no replacement joint available.

Cheaper than a transfer case dont you think considering I can buy a stock for 50 bucks if mine ever goes out

while i understand why chrysler might have gone this route, i don't know if i would agree with it and, based on what they are coming out with now in the mopar performance division, i think someone there may not agree with it too. also, i always found it odd that chrysler would choose to put an rzeppa joint at the t-case up front but NOT one at the pinion like they do in the rear. of course, we all know that they used a u-joint at the pinion flange up front.



don't kid yourself - all cv joints can and will go bad regardless if they are a u-joint style or rzeppa type. they are parts that see a lot of movement and stress and time and a lack of maintenace will ruin both. the only real difference is that one is a lot cheaper to maintain and replace and the other requires you to get a whole new driveshaft.

I am not kidding myself, I understand the life of various joints. What I am saying, with the double cardan joint may not be the best option in our jeeps. How many transfer cases have blown up with a rzeppa up front? Im willing to bet a whole lot less.

wayoflife

my mistake, i suppose you can call it that or whatever you want - i just have never heard of it being referred to ask much but hey, that's just me.

you are suggesting that ALL double cardin u-joint style drive shaft will break a t-case and, this simply is not true. my old TJ running double cardin u-joint style drive shafts and factory t-case had almost 200,000 miles on it and it never broke.

the problem of t-case breaks isn't in the type of joint used but rather, allowing vibrations to exist and lack of maintenance. and, don't kid yourself but, vibrations can even happen on a factory shaft using rzeppa joints as was the case for Northern Wrangler in this thread:

https://www.jk-forum.com/forums/show...ht=drive+shaft

funny, chrysler seems to think that a double cardin u-joint style drive shaft is not only a good option but, one they will be selling as an UPGRADE. guess they just don't know any better.

but, you are assuming that the t-cases blew solely based on the type of driveshaft being used and nothing could be further from the truth. the fact of the matter is, a well balanced, well maintained and properly installed u-joint style double cardin drive shaft will operate just as well as an rzeppa shaft and, in spite of what you seem to think, it will not break any t-cases. a u-joint style double cardin drive shaft should not be held responsible for operator error.

Ryanc

If you have never heard of it, then I guess you learned something today. Im not talking about a TJ, Im talking about a JK. There is no comparison. No, I never said that the double cardan ds will detonate the transfer case, all I am saying is that if it is not angled correctly it will increase the chance. That is just simple automotive mechanics. Quit frankly, Chrysler is not the sharpest crayon in the auto makers box. They have done some pretty stupid things with regards to design, etc and you know that. The thing is people are going to read your writeups ( which are really good btw ) except for your caster measurements. I know you put in a disclaimer. They are going to adjust this imaginary caster measurement based on how it drives. Well, once you get to that point of driving well, and you put in a double cardan driveshaft, you are increasing your chance of detonation because vibrations ARE going to occur. What is causing this problem is a differentiation in angular velocities. In actuality, simple mathematics is leading to the destruction. These driveshafts are not being installed correctly. Its not coast, je reel, etc etc fault, its installation error.

wayoflife

like i said before, what do i know.

i totally disagree. regardless of the type of jeep, we are talking about a double cardin u-joint style drive shafts. yes, the TJ came with a rear slip yoke shaft but, i had installed a slip yoke eliminator and was running a 1310 double cardin u-joint style shaft. of course, the front drive shaft on a TJ is already a double cardin design and so, there are a lot of similarities. if you install a drive shaft incorrectly, allow vibrations to exist and or fail to maintain it, it will fail and can cause significant damage to your t-case. in spite of what you seem to think, breaks like this have happend on TJ's and older jeeps in the past.

no, you just suggested it. and, i should point out that a lifted jk will cause your factory drive shafts to sit at a much steeper angle. on a 2-door, this will be significant in the rear. even on a 4-door, this increase in angle will be enough to cause the cv boots to be in a constant state of pinch and this will cause them to fail prematurely. this is especially true if you wheel your jeep often. this is just simple automotive mechanics and, unlike a double cardin u-joint style shaft, not something you can correct. of course, once the cv boots fail, the bearings inside will fail as well and, i think you know where i'm going with this.



yeah, i know that but i think they do too and i think that's why they are now going to sell 1310 drive shafts. unlike some companies, i think chrysler tries to learn from their mistakes and in this case, are trying to address them. or, at least, that's how i see it anyway.

you'll forgive me but, some drive shafts come with replacement yokes, some come with flanges and still, some come with adapters. all these things change the operating angle of the drive shaft and some options work a lot better than others. still, a well balanced drive shaft can and will operate just fine even at significant angles so long as they are spinning at slower 4.10 rpm or lower. at 5.13 or higher, sure, you need to pay more attention to this as the shaft is spinning so much faster but really, at a factory caster setting, i have found this to not be a problem. yes, it is something that the owner of the jeep needs to be aware of along with regular maintenance but, the same can be said about any modification you add to your jeep. or, at least that's how i see it.

look, you don't need to agree with me here but, for anyone looking to lift their JK 3" or more, u-joint style double cardin drive shafts are the ONLY option you have. up front, the narrower diameter shaft will clear your transmission and prevent pealing the sump pan off when flexing and it will also clear the skid plate better. in the rear, if you have a 2-door, an rzeppa shaft simply cannot operate at the significally increased angles for very long - this is a limitation due to their designed and, THIS IS A FACT. do a search and you'll find that this is a common problem and again, a u-joint style double cardin drive shaft is the only solution to this problem. now, all this is to say nothing about how painfully thin the factory drive shafts are and how they are more likely to do this if you play hard on the rocks....



sure, the rzeppa joint held but....

stlfan06

Sure, double cardan DS is the only solution right now... But AEV is working on making a replacement DS with the rzeppa joint that works at more extreme angles like the factory one, but skinnier so it doesn't have any trouble with the auto trans.

ronjenx

Regarding Ryanc's reference to front drive shaft pinion angle:

That is all true. With the front pinion angle being more than just a very few degrees, it causes the massive double cardan joint at the t-case to vibrate.
It it exacerbated the farther the double cardan is from the t-case.

For those who have their double cardan front drive shaft set up with too much front pinion angle, and have not exploded the t-case yet, it is only because they have not hit the critical harmonic frequency, for a long enough time.
The OP may be such a case. He had the stock 4.10's, so he didn't hit the critical harmonic, but the vibration he did have took a toll over the long term.

One of the vendors is now making the front axle with the diff rotated up with respect to the axle C's, thereby allowing a near zero pinion angle, and a good caster angle.
I would bet that is a result of their reading this forum.
Wayoflife is also correct when he says it's vibration that kills the t-case, not the type of drive shaft. Unfortunately, the type of drive shaft in question is often installed without regard to avoiding excessive pinion angle. And, like he mentioned, lack of proper maintenance is a factor, too.

wayoflife

yeah, they've only been working on it since sema 2009 along with adjustable upper control arms...



sorry, but not only is this old news but it's practically vaporware.

please note that we are talking about an rzeppa joint here and you CANNOT use them at "extreme" angles for very long as doing so would cause the cv boot to fail. this is a fact and there's no way around it. the only point to making this shaft is to be skinnier and clear the auto transmission. it will not addess steeper angles and, cannot be used in the rear.

wayoflife

yup - dynatrac is the one making the prorock 44 unlimited which, among other awesome benefits, has a built in +6° of caster. with it, you can set your pinion as needed to prevent vibrations and have optimal caster as well.