Driveshaft Angle and Phasing

[MadOgre]

"Nose Up" (relative to the ground) is immaterial; the driveline is only interested in the working angles between the various components - regardless of the relationship to the ground.

The truck could be upside down - but that wouldn't change the relationship between the driveline components.

See if this helps:

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

Summary: equal, opposite and "small" (less than three degress or so) is the key. Don't pay any attention to where the ground is. You can use angle shims to achieve the desired rear u joint working angle (cutting the center section out would be a bit extreme; perhaps only for the most hard core perfectionist).

K

Yep this is good informative stuff there Keith +1 for you and welcome to GMSB by the way!

 

[HotRodPC]

Most of who this info is going to pertain to is the guys who are doing 4x4 builds and lift kits is why I posted it. Obviously you can have a difference with the front and rear driveshafts having different angles. Though, it's my understanding the double cardan joint up front makes the differences less critical between front and rear.

 

[MadOgre]

Most of who this info is going to pertain to is the guys who are doing 4x4 builds and lift kits is why I posted it. Obviously you can have a difference with the front and rear driveshafts having different angles. Though, it's my understanding the double cardan joint up front makes the differences less critical between front and rear.

Im just curious because with my 6" lift the DC shaft has about 2-3 degrees on the forward joint that connects to the pinion and it seems like it needs rebuilding every other year. I even have the longer slip joint already.

This is one of the primary reasons why Im putting on the 4" lift and probably will even drop the transfer case 1" after that too

 

[shiftpro]

The double cardan CV joint is the only way to go imo. You still have to phase your joints but you can tip your rear diff to point directly at the transfer case and let the CV do all the work. At least that's how I understand it.

 

[mbl530]

Factory spec is less that 3 degrees for four link rear suspension; less that seven degrees for leaf spring rear.

This is because of the exaggerated amount of pinion nose wind up with a leaf spring suspension. If any of you have the opportunity to drive your truck without the pickup box on it - I highly recommend it. You will be surprised (I think) by the amount of windup during even mild acceleration and deceleration.

K

keith you are going to be the man for a lot of driveline questions, for sure. My question is in a long wheel base c10, with leaf springs and a 2 piece drive shaft, where there has been an axle flip, and Eaton Detroit 2 inch lowered leaf springs, for a static drop of 7-8 inch drop, my readings say the carrier bearing mount should be shortened about 1 inch to achieve the proper pinion angle. What are your thoughts on this. You can see my build on my profile page.

 

[Keith Seymore]

keith you are going to be the man for a lot of driveline questions, for sure. My question is in a long wheel base c10, with leaf springs and a 2 piece drive shaft, where there has been an axle flip, and Eaton Detroit 2 inch lowered leaf springs, for a static drop of 7-8 inch drop, my readings say the carrier bearing mount should be shortened about 1 inch to achieve the proper pinion angle. What are your thoughts on this. You can see my build on my profile page.

Normally you'd leave the front shaft alone (leaving the carrier mount/crossmember in the same location) and adjust the rear pinion nose, through the use of tapered shims. Shims would go between the leaf springs and the axle pads on the tubes.

Are you suggesting you would cut the front shaft (which would be added expense) or just moving the carrier bearing mount in the slots?

K

 

[mbl530]

Keith I wouldn't touch the shafts, front or rear. I would shorten the mount that the carrier bearing attaches to. this is what many of the after market guys suggest. I would rather take your advice.

 

[Grumpy Grizzly]

will I have a driveline issue after I lift

I'm planning on a 6" lift with the 1" transfer drop kit and just want to know if that will be enough or will I still have the possibility of slip out on the rear drive shaft.

 

[MadOgre]

I'm planning on a 6" lift with the 1" transfer drop kit and just want to know if that will be enough or will I still have the possibility of slip out on the rear drive shaft.

You should be ok. Just don't get too carried away offroad unless you get a proper length drive shaft built.

I have ran a 6" for years with the stock drive shaft. BUT it would be better for wear and tear if you had a properly lengthened drive shaft.

If you did a 6" lift with the extra 1" in the back to give it that nose down attitude then I would say the rear factory driveshaft will be to short. But drop the case 1" and maybe its ok ???

With 6" of lift you will need to do something about the front drive shaft as well.

 

[Grumpy Grizzly]

ok thank you for that info. Im thinking a CV front and rear at some point but the front worries me more because I cant just shim it like I can the rear. and we have long winters up here so I may need some rebuilding after winter.

 

[Grumpy Grizzly]

Also wonder the viability of a double cv front. I.e cv at each end. I've seenthis on some buggies (rock crawlers) when space was an issue. I used to be all Jeep and had a rock crawler myself, but just not sure with the longer drive shafts.

 

[JoshsC10]

I'm also having issues with this with a lowered truck, I just got my truck back on the road and there's a bad vibration, think it's the pinion angle, I have a 4/6 kit c notched would that cause the problem.?