square driveshaft

frankenyoter

frankenyoter

No Rain, No Rainbow
Joined
Mar 17, 2009
Location
DARK CITY
I recently punished my nice round balanced rear driveshaft. Going to order full sticks of tube and make new ones. Does anyone roll with a square rear shaft on a rig that sees road time? My rig will not be going over 45mph and will only go short distances across town to get a gallon of milke or hit some private property to wheel. How much of a good/bad idea is the square rear in my situation?
 
dont think it such a great idea , cant line it properly to the ujoints, should shake like you got the flu, and my opinion round is stronger, but try it ya may like it! good luck, may need a back brace soon LOL
 
Had a square rear shaft on a Toyota axled Sammi. It somehow did not vibrate at speed, well as fast as it would go, anyway, which IIRC was about 50.. :lol:
 
I use bell shaped pto shafts for my driveshafts on my 4Runner with 38.5 XMLS. It seems to not vibrated too much I just cut down the toyota cardan joint to fit the tube to it and did the same for the 9" side. I have like 3 ft of smaller tube in the shaft. I drive 40 miles a day for the past 3 years sometimes on the interstate but usually take backroads 45-55 mph due to fuel consumption. Im guessing the longer the tube is sleeved the less vibration cause my front shaft doesnt have much slip and it vibrates worse than the rear.
I wouldnt recomend square cause the shaft typically turns out to be 2" and mine is much smaller diameter. Also I think the manufaturer of pto shafts harden the steel when they shape it into a bell shape.
 
Thanks for the input guys. I am not going to dump money into a real driveshaft so I can do it again and again. I like the pto idea but the square stuff seems like it would take a serious beating and might be less coin. Where is a good source for the pto shafts? I know Tractor Supply carries some of that stuff.

If I can get a set of trail shafts made soon I might be able to keep the original ones for driving around the mall!:lol:
 
i used a peice of 3.5" (iirc) schedule 40 pipe. i cut the beer can out from between the joints and welded it in. been using it for several years now.
 
i run square drive shafts front and rear but i see no road time. I have beat the heck out of them and never broke one. Just make sure you weld them up good to the yokes, double or triple pass all the welds. I use 2.5 with .25 wall thickness and 2 with .25 wall thickness. The only complaint i have is they are a little noise
 
I have used square tube, PTO shaft, and Schedule 40. For the rear, my choice would be the schedule 40.
PTO is on the high side$$ for a rear, where you don't need as much slip. I would NOT use it at all single layered. It's about .160 wall
Square is strong, heavy and single tubed(using a stock slip joint) it would do OK, but, lil harder to get straight when you fit it up.
Schedule 40 is awesome for a rear shaft where you will use the stock slip. It's cheap, strong, and much easier to get centered.
For a front, where more slip is needed, I recommend and use PTO shaft. I have bent it, but never twisted it or broke it. For some reason tractor supply doesn't stock it any more. Last I found was at a tractor place in Rutherford county. It ain't cheap, unless you factor in what you will save buying a long slip shaft.
 
I use square. The rear doesn't vibrate below 45. The front will clank around and I've had clearance issues with my headers and the shaft. I've heard of guys welding a bead on the 2" and then grinding it down so it fits snug inside the 2.5". This might fix the clanking problem. They are heavy and stout.
 
I use PTO shaft from AGRI-Supply. It is triangular that is rounded. It has six points of contact in the slip area, not 4 like a square shaft. It is made to a much tight tolerance than square shaft slipped inside another. There are over 12 different sizes and wall thicknesses, so i found the 2 sizes that would adapt to my yokes as easy as possible. Both my front and rear shafts are made with this, and both have over 12 inches of overlap at the slip joint, and the front has about 23 inches of overlap. I drilled and tapped the slip area with grease fittings. All the pieces I used are .250 wall, and the larger piece on the rear is .320 wall. There is some vibration, but nothing more that i notice from 42" SX2's on unbalance recenter H1 12-bolts.

The plus side of the setup i'm running is that i've landed on the shafts under power on a rock, and nothing happened. It like landing on a link bar (If i had those.....)

For me it was cheaper for and i lost less time in my build than having custom shafts built.

If i saw any more road time, I would get a balanced nice custom rear shaft, and I plan to do so, but i dont have the time or the funds right now.

I drive the jeep 10-15 miles, 55mph to school and back about once a week, and i've had it on the highway at 70 mph, for over 80 miles. Nothing changed, vibrated or came loose.

I do notice more rear shaft vibes on deceleration and its coming from the slip joint getting wear over time. I feel that under acceleration, the torque going through the shaft, tightens the slip joint and takes the vibes out. The vibes are not coming from pinion angle issues, my pinion angle is set to 1 degree below the t-case output with a tration bar that has no play in it.
 
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