Drive shafts. u-joint/standard, CV, double cardan? (1 Viewer)

[DigitalPunk]

I am in the middle of setting up my SOA and ready to weld my spring purchase on the front, but first need to decide on what drive shaft with what pinion angle.

My front drive shaft can be pretty long since I am running advanced adapters SM465 to 3 speed conversion that adds a good 12+ inches and also did a spring flip with a reversal welding the pin at the front of the frame adding another 5 inches.

My rear I am doing a spring flip so I will gain some of that back but think I will still have a pretty short drive shaft.

What do you guys think? CV or double cardan rear and stick with a standard u-joint in the front? Or go CV on both? If CV or double cardan would you point the pinion directly at the T-case? If u-join would you keep them perfectly parallel with each other?

Thanks for your help!

 

[DigitalPunk]

If I go with a CV type shaft I would have to point the pinion directly at the T-case I believe and that would require me to drill another fill hole on the dif cover right? Because of the angle the dif wouldn't get enough fluid in I am guessing? Any trick to drilling a new hole without damaging the 3rd with metal flakes?

 

[Sharp38]

Tom Woods Driveshafts has a ton of technical info. Check out their website and go the tech section

http://www.4xshaft.com

Don

 

[reddingcruiser]

The rear is easy, just take off the cover. On the front you can use a vacuum cleaner or magnet to trap the cuttings if you don't want to disassemble the front end. Don't cut all the way through (except for the pilot), leave just enough you can take it out like an electrical knock-out plug so you can control where the rest of the metal goes. If you catch it right you should be able to put in a new bung and weld it up. Drain the oil and refill.

 

[DigitalPunk]

The rear is easy, just take off the cover. On the front you can use a vacuum cleaner or magnet to trap the cuttings if you don't want to disassemble the front end. Don't cut all the way through (except for the pilot), leave just enough you can take it out like an electrical knock-out plug so you can control where the rest of the metal goes. If you catch it right you should be able to put in a new bung and weld it up. Drain the oil and refill.

What do you guys think is the best route to go? CV, double cardan or standard drive shaft? The motor is a built 350, have a 465 and a 3 speed Tcase.

Trying to figure this out so I can weld my spring purchase and to my cut and turn.

 

[Cruiserdrew]

For the front shaft a regular drive shaft will work fine, since you never drive that fast with it engaged. Theoretically it might vib a little at high speed if you left the hubs engaged on the freeway, but likely you'll never notice it, and for anything but the shortest bit of high speed road between trails, you'll unlock the hubs anyway.

In the rear you can go either way but I've set both of mine up with DC driveshafts and believe it is better. Tipping up your pinion keeps it out of the rocks to a surprising degree.

One thing I did not see you mention, is that the shackle reversal will change the way you front shaft acts at the slip joint and you will likely need a long travel shaft in application like that. The geometry is hard to explain, but basically with the fixed point up front you basically double the shaft movement on compression. A Long travel slip joint is nice insurance you don't blow out the nosecone on the front of your t-case. I recommend you have your drive shaft shop set up up with a long travel kit. It's cheap insurance.

 

[DigitalPunk]

For the front shaft a regular drive shaft will work fine, since you never drive that fast with it engaged. Theoretically it might vib a little at high speed if you left the hubs engaged on the freeway, but likely you'll never notice it, and for anything but the shortest bit of high speed road between trails, you'll unlock the hubs anyway.

In the rear you can go either way but I've set both of mine up with DC driveshafts and believe it is better. Tipping up your pinion keeps it out of the rocks to a surprising degree.

One thing I did not see you mention, is that the shackle reversal will change the way you front shaft acts at the slip joint and you will likely need a long travel shaft in application like that. The geometry is hard to explain, but basically with the fixed point up front you basically double the shaft movement on compression. A Long travel slip joint is nice insurance you don't blow out the nosecone on the front of your t-case. I recommend you have your drive shaft shop set up up with a long travel kit. It's cheap insurance.

Thanks! so set my pinion in the front to be parallel with the T-case for the u-joint shaft and then the rear point directly at the output of the Tcase neg 1 or 2 deg for using the CV? I think this is the plan and will go out and get to welding. Thanks for your help, you guys are all awesome!

 

[handcannon]

If I go with a CV type shaft I would have to point the pinion directly at the T-case I believe and that would require me to drill another fill hole on the dif cover right? Because of the angle the dif wouldn't get enough fluid in I am guessing? Any trick to drilling a new hole without damaging the 3rd with metal flakes?

Never done just exactly this before, but could you plumb in some low pressure/ high volume air to the axle vent? Start the cut without air and as you start cutting through add in the air pressure and blow out the metal particles.

I did similar to this when I drilled my GM 6.5TD exhaust manifold for an EGT probe. I drilled through until the tip of the bit was just barely starting to go through the inside of the manifold. Then I started the motor and added a bit of grease to the drill bit tip. The exhaust pressure from the inside, and the stickiness of the grease kept all metal particles from going inside where the turbo could ingest any. Did the same thing when I tapped the hole.

Don

 

[reddingcruiser]

Just an FYI on raising the fill plug, normally I do it when everything is apart so I don't have to deal with shavings. I calculate the amount I need to raise the plug and mark the new location above the existing one. Then I lay out an oblong cut that that includes the existing bung, cut the piece out, flip it over and weld it into place. A little grinding, sanding and paint and it looks like it's always been that way.