Driveshaft Ideas

[strider]

I am running a 351W that is lowered between the frame rails roughly 2". It is bolted up to an AOD tranny which is also the mate to an NP205 t-case. I am running around 6" of lift. The axles are full-width from a 78/79. If the u-joints would fit, the front from the stock EB would bolt right in perfectly. The rear however seems too long and at a nasty angle.

What angle can I get away with on the rear driveshaft using the stock double cardan joint?

Should I be looking for the shafts from a FSB to cut down and use? I'm thinking about the u-joint size, knowing that I will have to cut the length down on the rear no matter what I do.

Money isn't growing on any trees near my house so the high-dollar custom shafts are not an option that I'll pursue, I'll be welding my own back together.

 

[DebosDave'72]

If the angle is that rough, you are probably going to want to change your pinon angle. I don't think it is an expensive procedure, but it will make the u-joint last a bunch longer, and prevent horrible drivetrain vibrations. That should make the driveshaft selection pretty straight forward also.

DD

 

[blazinchuck]

If you are running a rear cv shaft, the yoke on the axle should be in line with the driveshaft, maybe 2-3 degrees under. Thats only for CV's,regular u-joints have to matain angles on the front and rear of the drive shaft, hope this helps,Chuck

 

[RnrdTheFox]

Although I don't have as large a lift as you do, I still dug into this a few months ago for the same concerns. Here's the link with what I looked into and found out. The last post was the summary of my findings. Hope this helps some.

http://classicbroncos.com/forums/showthread.php?t=77737

 

[strider]

I am re-making my custom leaf mounts anyway so I can change the angle to whatever I want - so you're right in that its not expensive to do that.

My problem is that I don't know if I can get any angle to work well enough without some fancy CV joint or something.

any ideas? I can't be the first to do this.

 

[strider]

Thats strange, when I made my last post there was only one reply.

The articles noted in the referenced thread show what I've always called a double Cardan joint, not what I've always called a CV (Constant Velocity) joint. The CV joint, in my mind, is something like you see on a front wheel drive car's axle shaft.

Am I mistaken, or is the term CV being used for a wider range of products now?

Thanks though, I think I may be golden if I can use up to 24 degrees. I'm going to hit the yards tomorrow to get the FSB shafts, wish me luck.

 

[Skuzzlebutt]

The front wheel drive birfields are a different type of constant velocity joint. The double cardon joints were known as CVs since before the modern front wheel drives came to America. The term has been used for a variety of products for a long time.

Personally, I've owned 13 constant velocity carburetors over the years.

 

[Skuzzlebutt]

I am re-making my custom leaf mounts anyway so I can change the angle to whatever I want - so you're right in that its not expensive to do that.

My problem is that I don't know if I can get any angle to work well enough without some fancy CV joint or something.

any ideas? I can't be the first to do this.

I've no experience with your setup, but with the D20 mounts if you flopped the bushings top to bottom and vice versa it lowers the rear out put about an inch. That would correct half the angle increase caused by lowering the W.

 

[dixie134]

If you are talking about a 78-79 bronco , the 78 uses a different u-joint than the 79.Much smaller than the 79.hope this helps and good luck finding a 78-79 bronco driveshaft.It is not the same as those used under the pickups, they didn't have cv-double cardon joints.I also believe the cv joint is the part inside the h-block style part of the double cardon joint that is like a ball -socket type joint greased by a high pressure grease fitting.Good luck in you're search.

 

[welndmn]

The Stock 1310 CV is good for 30 degs of drop, after that it binds and blows up.