Driveshaft strength / failures.

I am in the middle of some upgrades, I am building driveshafts and have a few questions to those who have had driveshafts fail. Everyone knows a 1410 joint is strong as hell and a 1350 or Toyota joint is not far behind. My question is about tube diameter and wall thickness, also about the size of the tube shaft section of the driveshaft.
The tube shaft is the male splined section of the shaft welded to the tube. Most of the ones I have been using are 1.375" x 16 spline with 2" x .120" wall tubing.
I have "barber poled" a couple tubes but never broken the 1.375" tube shaft.
My current front 2 pc driveshaft will be using the front section of the rear driveshaft from a Ford Superduty, 3.5" tube/ 1410 joints from the t-case to the carrier bearing.
The midship tube shaft is 1.25" x 29 spline with a bolt on 1410 yoke. The midship is the same as my HP60 pinion so they are equal strength.

Am I overthinking using the 1.375 tube shaft in the front section? It's minor diameter is roughly 1.25" like the midship and HP60 pinion. It looks small / weak compared to the other components.
I have 2 options for tubing on the front shaft 2.375" x .188 wall or 2.5" x .250 wall. I think the .250 wall is overkill and will just be adding weight. The front shaft is very protected by the front links and I can not see it getting hit at all.

Has anyone barber poled a .188 wall shaft without it being hit or broken a tube shaft? If so lets hear the details.

Midship (http://www.northerndrivetrain.com/category/cat_driveshaftcomp_spltubeshafts_1-250-29invol.html)

Tube shaft (http://www.northerndrivetrain.com/category/cat_driveshaftcomp_tubeshafts_1-375-16spline.html)

I've bent a .120 wall rear shaft and twisted a .120 front drive shaft. Now all shafts are .250 wall. I run a single rear and two piece front. My buddy twisted a .120 wall mid shaft so don't skimp any where.

There's a formula that you can plug your driveshaft numbers in (length/tube thickness&diameter/ max rpm) that will Tell you if your d-shaft is up to the speed your car is capable of.

I build my driveshafts using northern drivetrains 1410 tube yokes to fit 2" .120 wall with the 1.375×16 splines. I sleeve the .120 wall with 1.75 .250 wall tube.

This has been great for me...keeps my shaft diameter small with lots of strength. Been holding up fine on my rocks and 54s with plenty of power.

I know this is as old thread but was close to what I was going to start so figured I'd bump this one.

Anyway, my question is basically how heavy is too heavy?

I had a 2.50 diameter .083 wall shaft that broke in the middle for no real reason. We had some 2.50 diameter .375 wall laying around work so I went that route. When it was all done and I picked it up, I about **** at how heavy it was. So now I am questioning if I should run it. I'm worried about the pinions carrying all that weight but maybe that is not a big deal. I didn't know if I'd start blowing seals or ruining pinion bearings or something. This is a front shaft if that matters.

Just a POS Jeep with 6cyl krawlers, dana 60 front, dana 300. So I don't NEED this heavy of tube but it was laying around so I used it. Do I retube it or run it?

I have run .250 wall without issue.

Re:

As long as it's straight you should be fine

Re:

I run .250 wall on the floor with no problems

Sent from my SCH-I545 using Tapatalk

It's definitely straight because despite me telling them not to, the shop balances every driveshaft they ever made me. I think they do it to annoy me.

Mathematically from what I can find, I think it equates out to 8.511 LBS PER FOOT OF TUBING and I'm 33.375" center yoke to center yoke in the closed position. I need to run the numbers against some .250 wall and see how much it varies even though .250 and .375 doesn't seem like a huge amount of difference.

Re:

Ok in that case I'd run it and not think twice.

2.5" 1/4 wall is super common in driveshafts. I run a pipe size that is slightly bigger than that on any Toyota shaft I've ever built.

Just think of it as having a piece of 2" 1/8 wall inside a "normal" driveshaft lol

I just made a 2.5 .25 driveshaft today for mine. Where are folks buying builder parts from?

94xjsport94 said:

I just made a 2.5 .25 driveshaft today for mine. Where are folks buying builder parts from?

Click to expand...

Ive bought most from Carolina Driveline and Northern Drivetrain.....For what its worth, i felt like the finish machining on the Northern parts was much better.

When I swapped to a different trans and t-case several years ago I rebuilt my front driveshaft out of 2" .375 wall. No problems to speak of since then.

I'm running 2" .250 wall driveshafts in my buggy with 44 inch tires and a ls with good luck so far. I used 05+ super duty 1350 slip yokes and splines with long slip th350 2wd yokes machined down for a press fit into the tube.

Mine are .188 chromoly and have had no problems at all

Here are the numbers I came up with off the Dana site in case anyone cares to know. I'm going to go ahead and run the .375 wall that is already built and quit worry about it.

2.50 OD X .375 WALL: WEIGHT FOR 24.00 INCHES IS 17.02 LBS (8.511 LBS PER FOOT)

2.50 OD X .250 WALL: WEIGHT FOR 24.00 INCHES IS 12.016 LBS ( 6.008 LBS PER FOOT)

2.50 OD X .188 WALL: WEIGHT FOR 24 INCHES IS 9.284 LBS (4.64 LBS PER FOOT)