Topic: Where to put the CV Shaft?

[birfection]

I'm running Rears Up Front and 63" Chevy leafs in the rear. I've just installed dual transfer cases, with an aftermarket crossmember.

I have one CV-type Driveshaft and one non-CV shaft. I plan on building a square shaft for the front. I never drive the truck at highway speeds in 4wd, but in 2wd my truck will see 80MPH. Should the CV style driveshaft be used in the front or rear?
What are your opinions/experience with this?

[yotaboy79]

I'd put it in the back. Pointless to waist it on a square tube shaft and running a single joint will help your d-line angle on the front

[yotatough]

I'd put it in the back. Pointless to waist it on a square tube shaft and running a single joint will help your d-line angle on the front

X2

[birfection [OP]]

When running the CV in the rear, can the rear pinion be tilted up without causing vibration issues at high speed?

I want to tilt it up to aid in clearance issues.

[yotaboy79]

You want the pinion pointed directly at the t-case flange or a couple deg. on the low side to account for axle wrap.

[birfection [OP]]

Yotaboy, you're referring to the rear application when using the CV end of the shaft at the T case?

[yotaboy79]

Yotaboy, you're referring to the rear application when using the CV end of the shaft at the T case?

Correct

[birfection [OP]]

To achieve this, it looks like I'll probably need to cut and rotate my perches

[yotaboy79]

Yup that's the way to go about it. If it's close run it and try it the worse that will happen is it will vibrate.

[birfection [OP]]

I've read TONS of info on how to make a square non CV-style shaft for the front.
However, I'm not finding any info on how to take a CV style driveshaft and lengthen it CHEAPLY to use in the rear. suggestions?

[yotaboy79]

If its the smaller diameter shaft theres a really easy way to do it. Heres what I do for the wheeler, cut the tube on the shaft so there's about 3" on each side and slide a piece of 2" sch80 pipe that is cut to the right length into the ends and weld it up. I've had good luck with this setup and haven't broke one yet. And they normally run pretty smooth if you take your time lining stuff up but it won't be perfect. You can also cut the end off of your factory rear shaft and cut the tube off the cv joint and mate them together the way they where designed too but it's gonna be harder to line it up and get it straight.

[birfection [OP]]

So you need to lengthen BOTH ends of the CV driveshaft?  could i leave the non CV side alone and just lengthen from the CV side?

[yotaboy79]

You want your welds close to the ends  only cutting one side could weaken it because of the after twisting and flexing at the weld joint you just want enough of the factory tube on each end to help center everything, then you slide the length of 2" sch 80 into the remaining factory tube on each end and weld it up, it's about as simple as it gets. Then again it's not that expensive to have it re tubed and balanced at a driveline shop

[birfection [OP]]

Thanks for the explanation. I will be driving a HWY speeds, so I'll be getting it balanced anyway. Maybe I'll check what they'd charge to tube it as well

[birfection [OP]]

I've done lots of searching on getting the rear driveline angle just right when using the CV driveshaft. Is it imperative to set this up with the BED of the truck on?
I mean, will the added weight on the springs change the geometry/angle?

[BLACKDOG]

Its not a bad idea, but it isn't necessary. 

Your axle should remain in a static position empty or loaded.  Its the springs and the shackles that are going to absorb the weight.  Your axle shouldn't "roll" one direction or the other once everything is bolted together.