How do these driveshaft angles look?

[ragedracer]

Good point, I hadn't considered that!

 

[throttleissues]

I'm still confused about the reasoning behind setting up the d-shaft angle for a 2 joint shaft.... it seems to me that if the rear end pointed towards the TC (making the yoke line up with the d-shaft so it's all in line) would be better but everything I've read/heard says that's absolutely wrong...

The d-shaft actually speeds up and slows down during it's rotation due to the angle in the u-joint. If both u-joints are at equal angles, and the d-shaft is in phase, the u-joints cancel each other out. If one has a sharp angle and the other is straight, you will get a lot of vibration, since they won't cancel. A double-cardan (CV) has both joints and cancels the vibration out within the CV joint, so you would want the 3rd joint to be nearly straight. Does that make more sense now?

 

[ragedracer]

Just went out and did a quicky booty fab TC drop. I gained/lost? 5 degrees. Looks like an 8 degree shim will work perfect now.

I'll probably do that tomorrow afternoon - ill let you guys know how it turns out.

ETA: The TC drop actually seemed to improve my front shaft angle as well. At least according to how the double cardan description on the Tom Woods site seems to suggest.

 

[Chaddy]

Just went out and did a quicky booty fab TC drop. I gained/lost? 5 degrees. Looks like an 8 degree shim will work perfect now.

I'll probably do that tomorrow afternoon - ill let you guys know how it turns out.

ETA: The TC drop actually seemed to improve my front shaft angle as well. At least according to how the double cardan description on the Tom Woods site seems to suggest.

The front shaft angle will be worse if you drop the t-case.

You need a CV joint at the rear of the t-case.

 

[Avery4jc]

The d-shaft actually speeds up and slows down during it's rotation due to the angle in the u-joint. If both u-joints are at equal angles, and the d-shaft is in phase, the u-joints cancel each other out. If one has a sharp angle and the other is straight, you will get a lot of vibration, since they won't cancel. A double-cardan (CV) has both joints and cancels the vibration out within the CV joint, so you would want the 3rd joint to be nearly straight. Does that make more sense now?

Crystal clear! Thanks for the explanation.

 

[hack]

Our local d-shaft shop (dicks driveline) does not like to use a cv joint on the rear d-shaft he can build a new d- shaft with a larger yoke, that and shiming your axel and droping the t-case will fix it. Did for me anyway.

 

[ragedracer]

Well, I took it for a spin after dropping the T-case. No more vibes (at least not noticeable). Cool!

I'm still going to shim the axle as the angles aren't optimal.

Thanks for the ideas!

 

[Chaddy]

Well, I took it for a spin after dropping the T-case. No more vibes (at least not noticeable). Cool!

I'm still going to shim the axle as the angles aren't optimal.

Thanks for the ideas!

How did you drop it? Did you just flip the spacers to the under side of the frame? If you did, the bolts will pull through the frame.

 

[ragedracer]

I used a piece of 1" tube stock. That looks to me to be all the drop "kits" are.


ETA: Why the heck didn't they just use shorter bolts, BTW? What is the point of those spacers anyway?