Mister Willie

So last night I was driving my 85 and had no problems. Smooth and easy. Well this afternoon when I got in and went to the store the truck had a hefty vibration at low speeds. I thought perhaps it was ice frozen to one side of the inside of a tire. Anyways, it didn't go away until I got on the highway.... hehe.

I got the truck up to 65 and the vibration was what I would call severe. I thought the truck was going to shake itself apart. Slowing down made it no better. Couple of seconds later.. WHAM. Sounded like someone hit my truck with a baseball bat.. really hard. But the vibration was gone and as I looked behind me, there were pieces of something sliding off of the highway.

I decided once I saw the pieces, for safety's sake, I better check it out. I pulled over and while I was waiting on traffic to clear, I put it in first and let out the clutch. No dice. It was not moving. No odd noises, no grinding. My instinct said driveshaft. So I looked. Sure enough, the entire driveshaft, from end to end, had made a rather rapid, somewhat violent, but thankfully benign departure from the transmission and differential.

I haven't had a real good look but I know the muffler has been hammered. It's got a huge dent in it and I'm sure it's got a sizable hole as well. Fortunately Fustercluck left me a spare driveshaft for another truck, so I'm not screwed. I just gotta get that new one in.

Anyways.... Any Ideas on what could have caused this? I'm thinking a seized Ujoint on the shaft. We've had several days of snowy weather and I had not greased the shaft at all since I've owned the truck. Any other guesses?

seaofnames

Some asshat loosened the bolts in the middle of the night?

Crackheads will steel anything!

drew303

I wouldnt say it was seized.. Probably just cracked, a cap fell off, and the ujoint failed... however, which one is a mystery. If it the upper fails, the shaft can act as a catapult... or of the lower fails.. it just drags... which wouldnt make the upper fail unless it was pretty weak too..and the the bouncing on the road caused it to spin around at some wacky angles causing the failure.. and the removeable of the whole shaft.

However.... you would of noticed a surge in rpm soon as the lower ujoint broke, did you?

I had the lower joint fail on the freeway but it didnt fall apart, a cap just came off.. nasty nasty vibration!

I think if the upper failed .. the shaft dropped, it could of grenaded the rear ujoint and you got lucky.. in that situation like i said, the shaft could act as a catupult.

what damage is done to the outputs of the tranny/3rd member? are the ujoin couplers still intact or gone/cracked?

Mister Willie

Like I said, fortunately the departure was benign. The outputs are still intact.

I know crackheads will steal anything. I had someone raise up my old Chevy lumina one night, pull off the tire and remove the banjo fitting from the friggin brake caliper, and lower my car onto the tire. That was a mystery cause I got a new banjo from the junkyard for... a dollar.