Failed U joint

[BigBlockMopars]

I have a 66 VIP w/ 727 383 4b and last year the ujoint failed and caused me a bent drive shaft and i believe a piece of the trans housing to snap (this was when i didnt know to much about the workings of cars). This happened quite some time ago however i am getting back into my Plymouth and ceasing my spending on my Acura. The day the ujoint broke was a Sunday in the morning time, I was cruising over to church around 730 got cut off on the on ramp by a scion TC and the irresponsible person inside me took over and i floored it. When i daily'd my fury i normally had it around 70 and hit 90 here and there so i never really thought much about catching up to this guy. Long story short i caught up to him and put him to shame (big win I know but i wasn't thinking) going upwards of 105, which is scary fast for me in that boat of a car. Then as i passed him up i was about to take my foot out of it and at that moment i hear this big thud and a hard vibration throughout my car. At first i thought i pushed her to hard and blew a gasket (since their was white smoke behind me) so i threw it in neutral and made my way over to the side of the freeway only to find my drive shaft on the foor. After telling my dad i have no idea why that happened, a couple grand out of pocket and the countless amount of "ive never seen this before" I had my plymouth fixed and i sat her in the back covered up. So my question is why did it fail, because of my speed or just because it was an original part, etc? Ive been thinking about gettin her back on the road or selling her for a 4 speed and wanted to know why this happened before i get back in it and make a decision.

 

[1978 NYB]

U-joints fail. I can't tell you the number of u-joints that I broke in the last 40 years....none recently. LOL! Your U-joint was probably original and probably worn pretty good. Massive torque on the u-joint while you were under acceleration probably helped it fail. I would say you have nothing to worry about. Obviously you have a new u-joint and drive shaft. I would replace both U-joints if you haven't already and get the driveshaft spin balanced. Chances are it'll never fail again.

 

[commando1]

Ah, I knew I was forgetting something to do........

 

[polara71]

When I was younger I broke dozens of those...

 

[70NPORT]

broke a few in my time as well.....nasty, drive shaft bouncing up and hitting the floor is not fun

 

[polara71]

It will scare the hell out of you

 

[70NPORT]

It sure as hell will

 

[1978 NYB]

I put a driveshaft loop on my Challenger after breaking a few.

 

[Supershafts]

It wasn't greased most likely and thats why it broke. In order to break a joint you have to exceed it's tq strength.

Which isn't going to happen in 2nd or 3rd gear with even a 440, figuring the joints spec is probably 1500 ft lbs for a 7260 it most definitely wasn't that.
Lack of grease intervals and or no grease intervals and or even mis-installed is more so what caused it, the shop that repaired or built you a new shaft should have been able to tell you why it happened when they seen it.
.

 

[commando1]

I'm looking at U-joints on RockAuto. 9-39 dollars WTF?

 

[1978 NYB]

Most of mine broke out of the hole with slicks and an adjustable pinion snubber. Always the rear joint.

 

[polara71]

Many engine mounts too. Those and U's every couple months

 

[1978 NYB]

Yep, left side motor mount.

 

[polara71]

Within a week I had both mounts broke plus the transmission mount

 

[1978 NYB]

After I broke the both motor mounts the first time, I checked the motor mounts and txsm mount EVERY time after taking her to Great Lakes Dragaway at Union Grove, Wisconsin. The track opened in 1955 and claims to be the oldest continuous operating dragstrip in the country.

http://greatlakesdragaway.com/

 

[commando1]

I broke trannies and rear ends. Damn u-joints never popped. Would have been cheaper.

 

[1978 NYB]

I broke a few yokes and grenaded a few 8.75's. My brother went with a Dana 60 in his 69 Dart GTS (originally a 383 car) 4 speed with a 440. I would of went with a Dana 60 also if I would of changed my mind about going in the Army in 1976.

 

[70NPORT]

I broke a few yokes and grenaded a few 8.75's. My brother went with a Dana 60 in his 69 Dart GTS (originally a 383 car) 4 speed with a 440. I would of went with a Dana 60 also if I would of changed my mind about going in the Army in 1976.

I've always wanted one of those.....69 Dart 383 or 440. That thing must have been a bear with that 4sp.

 

[1978 NYB]

I've always wanted one of those.....69 Dart 383 or 440. That thing must have been a bear with that 4sp.

I came home on furlough a couple years later and went for a ride with my brother. I was scared sh*tless!!!

 

[polara71]

Doing hole shots or "neutral drops" I destroyed many things in my car in my younger days. It got to the point I could pull and reinstall a 727 in less than 4 hours, by myself on my back with the car on ramps, in the driveway, or on the side of the road for that matter