Is there some type of adapter joint to convert a round tube to a square tube?

[slickrock]

I am in the process of making a front driveline and need to convert a dana 18 output to a 40 series pinion flange. The dana 18 has a small 1 ¼” solid tube for a driveline. Because of space while mated to an SM420, I need to keep this small diameter driveline for at least half the length of the DL. I was thinking of making a simple square driveline from the end of the 40’s flange (front half round, lower half square slip). Otherwise I am going to need a section that has a bunch of tube adapter sections to go from the 1 ¼” to the larger stock 40 drive line front section.

I’m not worried about balance for the front DL since the only time it will spin is whenI am in 4 wheel drive at slow speeds.

Does anyone know of some type of adapter that adapts a round 1 ¼” tube to a square tube maybe 2” or a bit larger? I have looked online, but I don’t think I am using the right words in the search to find what I am looking for. Any help would be appreciated.

 

[77TPIFJ]

how are your fab skills? i got an idea that i will draw out and post a pic for you..

 

[e9999]

I do recall seeing some square cross section propeller shafts every so often on backyard trucks and buggies. Must be some info out there.

Or is that only in the South...?

 

[77TPIFJ]

something like this good luck ... have a piece of solid square stock and have it machined to fit over your 1 1/4 piece of dl

 

[77TPIFJ]

or try this
How to Build a Square Driveshaft | eHow.com

 

[wadeclinton]

I'd look into getting round tube with the right inside/outside diameter. Get one piece of tube that matches your transfer case flange/yoke diameter, and a larger piece that matches axle slip/flange/yoke diameter. This piece would most likely be fairly heavy walled. You might have to get the section where they join machined/turned a little so they fit tight. Then weld them at the joint. A machine shop would probably be the best place for this. Those shops normally have small lengths of tube/metal left over from jobs, and may be willing to sell you the pieces cheaper than the steel yard. I suggest this because I've never been a huge fan of the square tube drive lines. The just seem to scream gyppo to me. As well as the vibration aspect, for example if you need 4x4 high to evade zombies. That is no time for a front driveline to start shaking you u joints apart. Just my 2 cents.

 

[crushers]

why the fawk does anyone run square tubing driveshafts?

 

[Pin_Head]

why the fawk does anyone run square tubing driveshafts?

Because it is a cheap way to get a long travel shaft without buying a long slip yoke. One side is made of 2 inch OD tube and the other is made of 2 inch ID tube so they telescope together. If you use 1/4 inch wall tube like used for receiver hitches, it is very durable on rocks too.

 

[crushers]

hummm, okay then, understood...

 

[slickrock]

something like this good luck ... have a piece of solid square stock and have it machined to fit over your 1 1/4 piece of dl
View attachment 498696

That's a good idea. Thanks!

As these things go, plans change (late last night while having a few beers and sitting int he garage staring at all the different driveline parts I had laying around). I was looking at the slip section on the D18 and that of my stock DL. I noticed that with a little grinding and some time, I could mate the two sections together and have plenty of meat to get a good weld on. Only thing I need now is a sleeve for the Cruiser's front DL since I have to cut it down to abut half the size. It won't be pretty, but it will work and compared to the 3" slip or so on the stock DL, I will have about 5 with the Dana DL top section.

If this doesn't hold up to the abuse, I'll give the solid chuck with a hole drilled in it a try.