Drive Shaft Fell Off

I’ve got a 1997 Dodge Ram with 150k miles. I was driving down the Parkway today and the drive shaft fell out of the rear differential. Is this a major problem? Can this be easily bolted back on or is this the end of my truck? Or something in between? I have no clue where I stand.

You probably just need a new U-Joint…about $25 for the part.

But you will need as hydrolic press to press the old one out and the new one in.

A shop may press in the new joint and you can take it home to install.

Yosemite

It depends, it might be as @Yosemite says, a u-joint. It is possible the screws just came loose or the yoke that attaches it to the diff may have broken. Even a failed driveshaft is no reason to assume the death of your truck. Either way, it is a simple fix.

Look at the drive shaft to see if the rear U-joint failed taking out the yoke.

If the joint is good, then the pinion shaft broke inside the diff. Which will require a used diff from a local auto used auto parts provider.

Tester

Bouncing down the road might have done some damage to the drive shaft. Evn losing a weight can cause some big problems.

Usually there will be some heavy vibration for several miles before a u-joint drops totally out. I’m curious what let go.

You have no clue where you stand ?? Neither do we.
This is a ‘‘look and see’’ situation with many variables. ( and we can’t look and see’’ )
Can you post some pics of the rear axle yoke area and the end of the drive shaft ?

You’re just darn lucky the FRONT of the shaft wasn’t the first to fail. It would have been driven into the next crack in the road and gotten driven up through the back of your truck.

After it fell on the road and bounced around, I would make sure it’s still in balance and not damaged, Other then that, everything could be pretty straight forward. As long truck diff did not suffer internal damage (v Tester). I would also use the opportunity to service the transfer case if you have one and the rear differential. Have the entire drive line serviced and looked at including all bolts and other joints, If there was weakqess there with age, there may be elsewhere. Be prepared to do a little preventative maintenance to the rest of the train.

I was driving. I noticed vibration when I let off the gas, but as long as I had my foot on the the pedal, it was fine. I was almost home, so I was hoping to avoid a tow. I did a quick inspection just now and I don’t see anything broken. The splines look fine. I can’t really figure out how it even came apart.

You will on a lift. I would have it done at a shop.

Did the driveshaft fall out of the truck, where you had to walk back and find it? The rear U-joint will be in sad shape… You will need a new joint and the special saddle-clamps that hold the joint in place on the rear-end pinion. 4 new special bolts too…Don’t use any of the old junk…

No. It was dragging.

“Can this be easily bolted back on…”

Are you saying that the nut holding the U-joint yoke to the pinion shaft came off?

If nothing else, new U joint time even if you can find the parts on the road. I’ve just used a large vice and a couple appropriate sized sockets to push out the old bearings and push in the new. So it doesn’t necessarily have to go to a shop with a press. But working outside in the cold is no fun.

If the rear axle s still in its proper place the only way the driveshaft can come out with the splines still attached is to break the rear u-joint or yoke. The splines are just a slip fit into the tailshaft of the transmission and it has to be free to slip forward and back a little as the rear axle moves up and down, so If a u-joint or yoke breaks the driveshaft then falls out of the transmission

If it has a 2 pc. shaft it would not necessarily fall out of the trans. The center bearing would hold it.

Got to look at it in daylight. I still don’t see anything broken. U-joint pivots back and forth in both directions. Nothing seems to be missing. It’s odd. It looks like the whole rear axle moved back a foot, the shaft dropped, and then everything moved back into position.

First you said, “… the drive shaft fell out of the rear differential.” Now you’re saying the drive shaft pulled out of the transmission? Which is it?

If something seems to have moved…you theorize the rear axle…check the motor/transmission mounts ! There’s a possible source of movement if you can’t get the rear axle to move. And you wouldn’t notice the bad mounts without it tourqueing under a load.

The rear U-joint is pressed into the driveshaft, then it is attached to the rear differential by 4 small bolts and two semi circular clamps. If the bolts backed out, broke off or were removed by a prankster, the driveshaft would simply drop to the ground at the rear. So my question, are the clamps and bolts at the yoke of the differential missing?

edit: I don’t know if this is possible or if it has ever happened before, but if the c-clips were mission from both sides of the driveshaft, maybe the caps for the U-joint backed out. If that happened, the U-joint could then come out of the driveshaft. So that begs the next question, it the U-joint still in the axle or is it in the yoke of the differential?

And lastly, what if the yoke on the driveshaft cracked where it goes around the U-joint bearing cap. This would make a little more sense as I believe that can happen. The cross section of the metal is pretty thin there.

This is starting to make little sense. Pictures would be nice.

There is a bolt that centers all the leaf springs and the leaf spring bracket fits over the head of this bolt. This is what keeps the rear end straight. This bolt can get sheared off, but I couldn’t see the rear end moving that far for the spline to get pulled out of the tranny, and then the rear diff moving back into place again. And you’d surely notice that the vehicle wants to drive sideways.

Yosemite