DIY Driveshaft, Slip shaft length

[KurtECV]

With most of the drivetrain done on the 93 LSXplorer (The Black Pearl), I am working on the front driveshaft currently.

The transfer case is a np241 (going to swap in an ECOBOX next year some time), the 241 uses a companion flange on the front output. I replaced a front driveshaft at work cause the splines were stripped out of the slip yoke.

Cut the male slip stub shaft off the chevy shaft, did the same for my factory 93 sport and kept the explorer stub shaft.

Tack welded the driveshaft and stub shaft together, and i am a few inches too long at ride height. Not a problem, easier to remove some tube than to add more.

my question is, how much slip should i have in that front shaft? 30% compression, 70% droop? 50/50?

The female slip yoke (factory X) is about 4.25" long.
Ive got about 12 inch travel shocks up front.

I have the software to field balance the shaft (on vehicle), will use a dial indicator minimize/eliminate runout

 

[dezertranger]

you should measure how much driveline plunge you have throughout the suspension cycle to know how much the slip will move from ride height up and then from ride height down.

examples with exaggerated numbers:
if you have 1" of rear ward plunge from ride height to bump then you know you need at least 1-1.5" of slip exposed
if you leave 1.5" exposed at ride height that means you have 2.75" of spline engagement. compare that to what your driveline plunge numbers are at droop and make sure the drive line wont pull itself apart.

 

[KurtECV]

you should measure how much driveline plunge you have throughout the suspension cycle to know how much the slip will move from ride height up and then from ride height down.

examples with exaggerated numbers:
if you have 1" of rear ward plunge from ride height to bump then you know you need at least 1-1.5" of slip exposed
if you leave 1.5" exposed at ride height that means you have 2.75" of spline engagement. compare that to what your driveline plunge numbers are at droop and make sure the drive line wont pull itself apart.

Yeah i figured that would be the best thing to do. Pain in the butt to remove my coil springs, assuming that will be the best way to compress the suspension.

 

[dezertranger]

what is the front suspension set up?

 

[KurtECV]

what is the front suspension set up?

Full width dana 44
TJ 9.5" lift 240ppi coil springs
Ballistic Fab adjustable upper coil brackets
f250 shock towers
custom Radius arms on heim joints
Hiem joint/DOM steering all around

 

[dezertranger]

AH yeah removing the coils will be a pain, but its really the only way to know for sure.

 

[KurtECV]

AH yeah removing the coils will be a pain, but its really the only way to know for sure.

And my RAs arent bent so the lower coil cups are canted forward, so when you remove the upper coil retainer they like to spring forward.

cutting and bending the square tube so the lower cups are parallel is on my to do list. Might do that when i do my Yukon ziplocker in the front

 

[dezertranger]

coil overs make things super easy. just sayn

 

[KurtECV]

that would be nice. If anyone wants to fund that project they are more than welcome!

 

[410Fortune]

My guess is you will find you have about 3" of slip, MAYBE 3.5 at the slip yoke if you have lots of droop travel.

 

[KurtECV]

My guess is you will find you have about 3" of slip, MAYBE 3.5 at the slip yoke if you have lots of droop travel.

I think i have a good amount. When i lift the truck in the center, the rear tire is a few inches off the ground, and the front just laughs, IIRC the rear is several inches off the ground once the front is off the ground.

 

[gmanpaint]

 

[KurtECV]

STALKER!

 

[gmanpaint]

Lol. I am following because I'm in a similar situation with mine, after adding the atlas. The length changed, and the slip exposure is questionable.

And I will stalk you if I wanna!!

 

[KurtECV]

Lol. I am following because I'm in a similar situation with mine, after adding the atlas. The length changed, and the slip exposure is questionable.

And I will stalk you if I wanna!!

That would suck to have to change yours, you spend big money on your shafts!

 

[gmanpaint]

Well, I should have said after swapping to the 5.0 drive train, the lengths changed. I got the new thick wall shafts after the atlas, with the 4.0

There is a 2" difference with the 4.0, and 5.0 at the outputs.

 

[KurtECV]

Well, I should have said after swapping to the 5.0 drive train, the lengths changed. I got the new thick wall shafts after the atlas, with the 4.0

There is a 2" difference with the 4.0, and 5.0 at the outputs.

Did it push the locations (of the outputs) back 2 inches??

 

[gmanpaint]

Did it push the locations (of the outputs) back 2 inches??

There is about 2" more slip exposed on the rear shaft, after the swap.

Place that made them, told me they used a 6" slip on them, so it hasn't been a real concern, but more of a curious one.

 

[KurtECV]

Wish we would have checked that on the RTI ramp at smoor