Twisted Frt. Drive Shaft--How'd that Happen??--Any Ideas??

[ROVERP6B]

My son brought my GW back with a vibration. I discovered it was MUCH worse in 4WD. Just took off the Front Driveshaft and found it was bent. I was wondering what he did to bend it. After sliding my hand up and down the shaft(driveshaft!), it felt like a twist in the shaft. After closer examination, looking at the extruded 'seam' on the tubing, I could see that the tube had been twisted. So, I believe that the tube twisted under torsional stress. But how common is this? Was he pulling a dump truck or something? Has anyone done this on the trail? I can't whip him anymore(he's too tough,and I'm too old) but I sure would like to know how to keep this from happening again. If you guys have seen this before, let me know. I'd like to hear your ideas. Thanks! Mike.

[Crazy_Jeepman]

Possible it was spinning hard and grabbed traction. Not really common that would happen, I would not worry about just replacing it. Keep the wheel speed down when spinning. Strange that you are seeing a Seam......I thought driveshafts were seamless. Maybe a bad driveshaft in the first place.

[Wagillac]

I dont think that most drive shafts are made out od seamless tubing. They are usualy DOM tubing which has a seam.
Seamless tubing is mainly used in high pressure applications.

[J20 project]

High torque, grabbed traction, nice twist. Simple as that. Oh and DOM stands for drawn over mandrel, meaning it is squirted out through a tube with a center section, just like your playdoh toy when you were a kid. Most driveshafts are seamed type tubing, balancing is a must. I can make a vibration free driveshaft with nothing more than a lathe to spin it true using DOm tube. J20

[carrotman]

In the early 80's, I was driving a Dodge Ramcharger near Moab, UT in granny gear, low range. Tried to get over a large boulder. Too much torque twisted the rear drive shaft into a pretzel, about 10 inches shorter than normal. Had to limp back using front wheel drive and winch.

[ROVERP6B]

OK...we have had a lot of ice/snow. So I suspect the theory of spinning and grabbing traction is plausible...but man...I would think it would take a lot of umph! Perhaps it was in low range when it happened. Maybe BF Goodrich can use this. You know, "You want driveshaft twist'n traction, pick up some BFG All Terrain Tires". Gear Head, I think the 'seam' I see is in fact an extrusion mark where the tubing was squirted out through a form. It is not a welded seam. So, I have the choice of a junkyard shaft with a questionable double cardon joint, or the drive line shop for a new tube.

[carrotman]

Rover, you can still get kits to rebuild the cardon. It's just two U-joints and a center roller, bushing and seal.

[ROVERP6B]

OK, Carrotman. That's good to know. I had an old Dbl Cardon that was not greased by the PO. It had a ball and socket in the center that was worn and sloppy due to wear and rust. Looked like it would be an expensive repair.

[Bob Barry]

There was a thread a few days back about entire replacement driveshafts through Autozone or the like.

In any case, climbing a rock wall full-throttle with the fronts catching air, then landing without lifting, can cause the driveshaft to twist until it sardine-cans itself open at the weakest point:

http://home.off-road.com/~wagoneer/cherokee/carn01.jpg

You can be sure your son was having fun!

Still, the newer GW's use a much larger tube than the earlier FSJ's did (like the original tube shown above from my '78 Cherokee), so he must have been having a LOT of fun... smile.gif

[ROVERP6B]

Thanks Bob!! I'll look for the driveshaft thread. And what a picture you have there!! I guess I just didn't realize the power involved here. This one is maybe 1/2"-3/4" out of line, but I can see from your pic what happens if you keep going. This tube is 1 3/4" in diameter...off of an '85. Looks about the same as the one in your picture. I'd put one in here if I knew how. FAQ said you can't attach files. Thanks!! Good Info!! I'll just smack him and run!

[Wagillac]

Originally posted by J20 project:
High torque, grabbed traction, nice twist. Simple as that. Oh and DOM stands for drawn over mandrel, meaning it is squirted out through a tube with a center section, just like your playdoh toy when you were a kid. Most driveshafts are seamed type tubing, balancing is a must. I can make a vibration free driveshaft with nothing more than a lathe to spin it true using DOm tube. J20DOM is drawn over mandrel but that just shapes the tube to the exact size and smothes the seam. DOM mechanical tubing still has a seam it starts out as a flat stock just like HREW. It is rolled welded then drawn over mandrel. Seamless tubing is extruded.
You shuld read this thread. Look for posts by BillaVista.
http://www.pirate4x4.com/forum/showthread.php?s=&threadid=212269&perpage=25&pagenumber=2

[mdill]

I would immagion that if you were really into this
stuff, you could use some 4130 seamless tubing to
make your drive line, would not add that much to the
total cost smile.gif Would make for one nice driveline,
but you would have to be careful with the welding
and be sure to aneal the heat effected areas.

Mike D.