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CV shaft w/o SYE?

N

noresttill

NAXJA Forum User
Location
South Florida
Quick Question:

If after a lift the pinion angle creates havok with the slip yoke in the transfer case, and the solution is to get rid of the slip yoke on the Tcase (sye) and add a CV axle for axle travel:

Why cant you just replace a rear driveshaft with a CV one and not add a sye? wouldnt the strain be off the Tcase?

I probably missed something, but the thought just came to me.

Just wundrin'
 
Umm, because the factory setup is a slip yoke, ie - the output on the transfer case is a splined shaft, and the driveshaft slips onto that shaft and bolts to the axle yoke. In order to run a CV shaft, you have to install a solid yoke on the t-case or the CV shaft won't have anything to bolt up to. In other words, you can't run a CV if you don't have yokes to bolt to on the t-case and axle end.
 
MrClean said:
Umm, because the factory setup is a slip yoke, ie - the output on the transfer case is a splined shaft, and the driveshaft slips onto that shaft and bolts to the axle yoke. In order to run a CV shaft, you have to install a solid yoke on the t-case or the CV shaft won't have anything to bolt up to. In other words, you can't run a CV if you don't have yokes to bolt to on the t-case and axle end.
Click to expand...

Not true,but also not recommended.
CV_Rev_Slip_575x50.jpg
 
I've only ever run SYE or factory slip yoke. I've never had to do a hack n tap, how reliable is it? I always hear a 50/50 from people that say it's garbage and people who run them with no problems. Can this be done on a 231, or only on 242, etc?
 
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MrClean said:
I've only ever run SYE or factory slip yoke. I've never had to do a hack n tap, how reliable is it? I always hear a 50/50 from people that say it's garbage and people who run them with no problems. Can this be done on a 231, or only on 242, etc?
Click to expand...

Youve got it a little backwards.With a 242 you can only do a H-n-T or a TW shaft.With the 231 you can do what should have been done by Jeep in the first place.Heres a HD 231 shaft compared to stock!
014_11.JPG
 
RCP Phx said:
Youve got it a little backwards.With a 242 you can only do a H-n-T or a TW shaft.With the 231 you can do what should have been done by Jeep in the first place.Heres a HD 231 shaft compared to stock!
014_11.JPG
Click to expand...

That's pretty much what I meant, on my 231's I've only done SYE. I was asking if H&T could be done to a 231, or only to a 242? On the 242, is it reliable? I should have phrased it different, sorry.
 
Only question I have with the HD 231 shaft... what drives the VSS?

Like RCP posted, you *could* use a solid (non slip jointed) shaft and a CV slip yoke, but it will put more weight on the slip yoke and I wouldn't want to do that personally. Heck, the yoke most (if not all) people use for a H&T is the 3103-27CV, which is actually a slip yoke.

What you really don't want to do is run the 3103-27CV slip yoke as a slip yoke with a stock front shaft used as a rear shaft. That means you have two slip joints... what happens when both fully compress at the same time? You spit out the driveshaft.
 
kastein said:
What you really don't want to do is run the 3103-27CV slip yoke as a slip yoke with a stock front shaft used as a rear shaft. That means you have two slip joints... what happens when both fully compress at the same time? You spit out the driveshaft.
Click to expand...

That's what I was thinking.. Hate for that to fall out at any speed, lol. There goes your DS and potential damage to other parts as well.
 
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kastein said:
Only question I have with the HD 231 shaft... what drives the VSS?
Click to expand...

Here is the complete kit,the little blue gear just slips on to the splines!
006_3.JPG
 
noresttill said:
Quick Question:

If after a lift the pinion angle creates havok with the slip yoke in the transfer case, and the solution is to get rid of the slip yoke on the Tcase (sye) and add a CV axle for axle travel:

Why cant you just replace a rear driveshaft with a CV one and not add a sye? wouldnt the strain be off the Tcase?

I probably missed something, but the thought just came to me.

Just wundrin'
Click to expand...

The pinion angle doesn't create havoc with the slip yoke. Many vibration issues can be addressed on moderate lifts by taking into account the actual driveshaft angles and shimming the appropriate side. Most folks don't want to mess with that and simply install a SYE and a DC driveshaft.

However, when you get beyond a certain point, the problem is generally 2 fold. Not enough slip yoke left for the amount of axle travel (danger of dropping the DS on the trail) and the angles are too extreme for the u-joints to get smooth operation at high speeds (Vibrations remain after DS angles are fixed).

The SYE fixes the rear yoke to the Transfer case eliminating the DS from pulling out.

The DC shaft with a intregal slip joint does two things. It gives you a longer slip joint which is in line with the drive shaft (no possible binding), and the double cardan join divides the u-joint angles giving you smooth operation of the DS.

Installing a DC DS with a slip yoke leaves you with the slip yoke length issue.

Installing both takes care of both issues. A Hack and Tap setup can be done very inexpensively.

Hope that explains it.
 
kastein said:
What you really don't want to do is run the 3103-27CV slip yoke as a slip yoke with a stock front shaft used as a rear shaft. That means you have two slip joints... what happens when both fully compress at the same time? You spit out the driveshaft.
Click to expand...

This pretty much answered my question. Reading back my post it really isnt written very well, sorry. I know about the sye and hack and taps, but why would a fully compressed slip joint DS with with SYE be any different than 2 fully compressed slip joints? Or would the DS never compress that much with a SYE due to shortened Tcase output.

Thanks again
 
but why would a fully compressed slip joint DS with with SYE be any different than 2 fully compressed slip joints? Or would the DS never compress that much with a SYE due to shortened Tcase output.
Click to expand...
Slip joints are not spring loaded, the position they are in becomes static unless you pull or push on the joint.

So...

A slip joint needs something to push or pull against.

The T-Case slip joint in a normal set up slides back and forth because it is tied to a DS that is fixed at a point (The axle).
The slip joint in DS with a SYE slides back and forth because it is tied at a fixed point (The axle).

Now install 2 slip joints...
What do the slip joints work against? Nothing, the leverage is gone unless the compressed travel limit on both slip joints is maxed out. If the one in the DS compresses, it will not expand (no leverage) and cause the one at the TC to pull out, just like the post above states. See, it doesn't work.

Rule of thumb: Only 1 slip joint per drive line.

You either use a slip joint at the TC, OR you set up a fixed yoke (SYE) and install a slip joint in the DS.

Ron

Edit: Sorry for all the edits!
 
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I have a Ribicopn Express 3.5 inch lift and after doing my NP 231 SYE kit from rugged ridge ($169 on ebay) I used my FRONT driveshaft on the rear and it worked great. I got another front shaft from a wrecking yard for $20 and put that back in the front. So basically I have two identical driveshafts in my XJ and they have been in there for a while now and many a wheeling trips and I have NO problems. If you go higher than 4 inches in lift you will need to get something else as this has only about 1.5 inches of travel left in it before it is maxed out. This is a great and cheap way to not have to pay $300 plus dollars for a "custom" driveshaft. Plus there are lots of front shafts in wrecking yards so you can get them cheap.
 
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I am at 6.5" in the rear with a 44 and a 231. I went the 3103-27CV route with a factory front shaft.

So far, I have no complaints. The pinion is shimmed down about 2 degrees to allow for some spring wrap.

I drilled and tapped the existing 231 output shaft (3/8"-24) and left the factory tailcone bearing in place. I then machined a special washer to hold the 3103 slipyoke in place without preloading the snapring on the tailshaft bearing.

The real downside was the drilling and tapping, -even with carbide was a frustrating ordeal, -and I machine metal for a living. I also machined a drill guide bushing that slipped over the splines of the tailshaft to help keep me drilling straight when I was putting everything I had into pushing on that dang thing. I also went through two taps, -although they were high speed steel, -not carbide, -but got 'er done.

The upside, $100 for the 3103 yoke, and $20 for a mint (like new) stock front CV shaft, -hard to argue with the cost and how good it works.

I could have hacked, then tapped, -which would have made the drilling and tapping easier (getting through the case-hardening), but then my stock front driveline idea wouldn't have worked, because it would have been too short.

Not a lot of money, but a lot of work, and it works great so far.
 
ratman572 said:
I am at 6.5" in the rear with a 44 and a 231. I went the 3103-27CV route with a factory front shaft.

So far, I have no complaints. The pinion is shimmed down about 2 degrees to allow for some spring wrap.

I drilled and tapped the existing 231 output shaft (3/8"-24) and left the factory tailcone bearing in place. I then machined a special washer to hold the 3103 slipyoke in place without preloading the snapring on the tailshaft bearing.

The real downside was the drilling and tapping, -even with carbide was a frustrating ordeal, -and I machine metal for a living. I also machined a drill guide bushing that slipped over the splines of the tailshaft to help keep me drilling straight when I was putting everything I had into pushing on that dang thing. I also went through two taps, -although they were high speed steel, -not carbide, -but got 'er done.

The upside, $100 for the 3103 yoke, and $20 for a mint (like new) stock front CV shaft, -hard to argue with the cost and how good it works.

I could have hacked, then tapped, -which would have made the drilling and tapping easier (getting through the case-hardening), but then my stock front driveline idea wouldn't have worked, because it would have been too short.

Not a lot of money, but a lot of work, and it works great so far.
Click to expand...

I tried the same thing 10yrs ago on my 2000,it did not work well at all.Still had minor vibes,went directly to a HD SYE kit and haven't looked back!
007_4.JPG
 
i see double slip joints^^^ or is that the heat getting to me?
 
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