Low Low

[thegoat4]

I wouldn't run it either because of the premature wear on the u-joints. That is the only reason.

You're also very wrong that a u-joint is a u-joint. Some are VERY different from others.

Have you read the ~15 page 401 article on pirate regarding driveshaft and u-joint tech? I have. It's a good read for anyone who hasn't. I'm not pulling this information out of my ass. It's from a reliable source.

You mean this: http://www.pirate4x4.com/tech/billavista/PR-shaft/index.html ?

I can't find anything in there that states some u-joints somehow don't get more severe harmonics at high operating angles. FWIW, I'm the guy in my shop who deals with pretty much all NVH complaints so the training I've been to is probably slightly more detailed than that article. And even in all of my training and all of my experience repairing driveline vibrations there was never a special u-joint that defied physics.

There are two things that'll let you get away with excessive angles before vibration sets in: a lighter driveshaft, or a slower driveline speed. And the slower driveline speed matters a hell of a lot more.

Like I said up front: that shaft will fly just fine off-road since it'll be going slow. But since he has a doubler more than likely he'd like to be able to drive on the street. Not gonna happen with those angles.

In copykat's case, he's going to use a CV. He should be OK with that since the bend will be spread over more joints and each will see a much smaller working angle. But it'll still come down to what the final angles are and how fast the shaft will spin.

 

[CopyKat]

My 21" Long rear driveshaft is in and whadaya know it works!

No point continuing this thread. cuz my driveshaft is so short.