Homebrew 3103-27CV SYE Details

[multmigs]

I've read all this and I'm still confused, why don't you have the yoke cut down more or the axle output shaft shorter so that it seems like the yoke would be flush with the seal and then the front driveshaft is a direct fit? is it simply to gain more length on the spline engagement?

 

[Hylander]

I've read all this and I'm still confused, why don't you have the yoke cut down more or the axle output shaft shorter so that it seems like the yoke would be flush with the seal and then the front driveshaft is a direct fit? is it simply to gain more length on the spline engagement?

Cutting the Shaft or Yoke shorter won't get the Yoke any closer to the Seal as the Shaft is thicker were you see my Yoke sitting, it is resting against that thicker shoulder.
You are correct, the Yoke and Shaft have more Spline engagement.
Most guys are cutting the Shaft to leave 1.25" or even 1" of Splines.
When mated to the 3103-27CV Yoke that will only leave .75" or .5" of Spline engagement respectfully.
The reason is that there is .5" of freebore in the 3103-27CV Yoke.
I prefer to have 1" of Spline engagement
Study xjbrian drawings closer and you should understand.

 

[multmigs]

I think I got your idea now, I guess the only problem is what driveshaft could you pull from a JY that would just bolt in like this, might depend on ones lift height as well. I wonder if there is some way to cut to a length between what you did and the ones recommended with the kits like IRO?

 

[redrider2911]

will this work? slightly different part number and it doesnt say np 231 but the same spline count... maybe a different diameter?

http://www.dennysdriveshaft.com/p43...v_yoke_26_spline.html?submit=More+Information

 

[redrider2911]

crap wrong thread.

 

[redrider2911]

wow, i must be tired, by the time i found this there has just been alot more replies so it looked like the wrong thread. NO IM NOT ON DRUGS!:shhh:

 

[FlexdXJ]

How did you fit the oil seal? Or how did you stop the oil from leaking out?

On the 97+ t cases you don't have to worry about that. They put a different seal in it!

 

[jk_surgeonfish]

A little off topic but on your rear transfercase output shaft do you have some end play? I can take mine and move it up and down less that 1/8 inch and was wondering if this is norm? If not, I am going to order a full SYE kit... but if nothing to worry about I plan on doing the 3103 yoke as detailed in this thread. I have vibes on my 99 with 2 inch lift.

 

[Hylander]

A little off topic but on your rear transfercase output shaft do you have some end play? I can take mine and move it up and down less that 1/8 inch and was wondering if this is norm? If not, I am going to order a full SYE kit... but if nothing to worry about I plan on doing the 3103 yoke as detailed in this thread. I have vibes on my 99 with 2 inch lift.

I thought I did when it had the slip yoke on it, turns out it was play in the slip yoke.
With this setup I have no play.
I would take the slip yoke off and see if you have play with just the shaft.

 

[Hylander]

I think I got your idea now, I guess the only problem is what driveshaft could you pull from a JY that would just bolt in like this, might depend on ones lift height as well. I wonder if there is some way to cut to a length between what you did and the ones recommended with the kits like IRO?

The stock front XJ shaft works as is, it was just alittle short for my taste.
Others also cut the output shaft .25" - .5" shorter which allows the driveshaft to have more slip.
Like xjbrian, I wanted a full 1" of spline engagement on the output shaft
Like you said, lift height will play a role in what will work and won't work as far as lenght is concerned.

 

[jk_surgeonfish]

I thought I did when it had the slip yoke on it, turns out it was play in the slip yoke.
With this setup I have no play.
I would take the slip yoke off and see if you have play with just the shaft.

Good idea.... did not think of doing that. Thanks.

 

[jk_surgeonfish]

I thought I did when it had the slip yoke on it, turns out it was play in the slip yoke.
With this setup I have no play.
I would take the slip yoke off and see if you have play with just the shaft.

Ok... I pulled the DS off and you were correct, the play was in the yoke and not on the output shaft. I feel better now and will go foward with the 3103-27V method. Now... I just need to find a front DS and order the yoke....

 

[Hylander]

Ok... I pulled the DS off and you were correct, the play was in the yoke and not on the output shaft. I feel better now and will go foward with the 3103-27V method. Now... I just need to find a front DS and order the yoke....

Good to hear:
The only place that I know of that might have a Yoke in stock

http://www.driveshaftspecialist.com/?gclid=CPWRvuaryJ4CFRESawodamStrA

http://www.carolinadriveline.com/

 

[G.P_XJ]

Great how-to write up, I would attempt this on my jeep but i dont really trust my own work as far as cars go

 

[Muddy Beast]

So I have a question... I did my Hack and Tap today and once I put the shaft on I found I had 2.5" of the drive-shafts travel exposed, meaning I only have an inch of room for the axle to droop. Is this OK? It seems most want little up travel and lots of down travel, but I guess in my measurements I didn't calculate the angle/length difference (I WAS trying to only have an inch of up travel).

Should I drop the bones to have the DS lengthed a smidge?

~Scott

 

[kastein]

What angle is it at, and how long is it at ride height?

"ground" length = length of driveshaft @ ride height * cosine(angle from horizontal)

vertical difference at ride height = length of driveshaft @ ride height * sine(angle from horizontal)

Now add the amount your wheels droop below ride height to the vertical difference @ ride height number, divide that by the "ground" length number, take the inverse tangent of the result. That'll give you the angle the driveshaft will be at full droop. Take the cosine of that, reciprocal, then multiply by the "ground" length again, and you have the length the driveshaft needs to safely extend to at full droop. Unless I screwed up on some of my trig, that is.

 

[Muddy Beast]

What angle is it at, and how long is it at ride height?

"ground" length = length of driveshaft @ ride height * cosine(angle from horizontal)

vertical difference at ride height = length of driveshaft @ ride height * sine(angle from horizontal)

Now add the amount your wheels droop below ride height to the vertical difference @ ride height number, divide that by the "ground" length number, take the inverse tangent of the result. That'll give you the angle the driveshaft will be at full droop. Take the cosine of that, reciprocal, then multiply by the "ground" length again, and you have the length the driveshaft needs to safely extend to at full droop. Unless I screwed up on some of my trig, that is.

I don't know what the rear end is at full droop. :-/

I'm just hoping the rear end doesn't commonly droop enough to use more than 1" of the DS downward travel.

~Scott

 

[kastein]

Shouldn't be hard to figure out - if it's all bolted up already, measure the flare to wheel center, then jack the rear end up by the frame till the wheels are off the ground and measure again, add however much you think they'll spring down if you jump it or something, then subtract the ride height measurement, that'll be the difference in vertical height.

My suspicion is that you'll be ok, but I have absolutely no numbers to back that up.

 

[Muddy Beast]

My suspicion is that you'll be ok, but I have absolutely no numbers to back that up.

I think I'll just rely on that, and find out for sure tomorrow when I go wheeling.

Regardless, jacking the rig up till the tires are off the ground would take a huge jack...and that is something I do not have. I don't even think 2 hi-lifts could do it unless they were 64" ones. I went to the flex ramp and measured, I only used .5" on the DS, so hopefully I don't use more then that.

~Scott

 

[Hylander]

Regardless, jacking the rig up till the tires are off the ground would take a huge jack
~Scott

Just jack the Rig up under the Axles as high as you can.
Next place jack stands under the body and then lower the jacks under the Axles so the body rest on the jack stands, stretching the suspension.