Broke drive shaft from rear end. HELP

[mopar70]

Driving down the road and heard a loud snap and then the drive shaft broke off the rear end from the yoke and fell down. Lit up the wheels at the lights before :toothy12:. 1970 challenger with 383 and 727 trans was told it has a 8 3/4 rear but don't know why the u joint broke so easily. I did hear ticking noise the day before but it went away after a while. I think its the u joint not sure because I had to tow the car home and it got to dark. This car was originally small block and I want to know what suspension and drive train stuff I should upgrade. I know it has new leaf springs, torsion bars and shocks. I want to make sure the cars solid before I start driving it again because I was lucky I was turning and not driving fast. Thinking about doing the hotchkis tvs system and 4 way disc brakes and firm feel steering box. Also when I bought the car I was told it has a sure grip but only one wheel spins.

 

[mopar70]

Is this a good investment

http://www.ebay.com/itm/Metco-MDL19...Parts_Accessories&hash=item4844bdc525&vxp=mtr

 

[PST]

Driving down the road and heard a loud snap and then the drive shaft broke off the rear end from the yoke and fell down. Lit up the wheels at the lights before :toothy12:. 1970 challenger with 383 and 727 trans was told it has a 8 3/4 rear but don't know why the u joint broke so easily. I did hear ticking noise the day before but it went away after a while. I think its the u joint not sure because I had to tow the car home and it got to dark. This car was originally small block and I want to know what suspension and drive train stuff I should upgrade. I know it has new leaf springs, torsion bars and shocks. I want to make sure the cars solid before I start driving it again because I was lucky I was turning and not driving fast. Thinking about doing the hotchkis tvs system and 4 way disc brakes and firm feel steering box. Also when I bought the car I was told it has a sure grip but only one wheel spins.

We can help you with most of the suspension upgrades that you are looking at. I can put a kit together if you would like that would cater to your needs. We carry geometry correcting upper tubular control arms, adjustable struts rods, solid or tubular sway bars and frame connectors. As for a 4 wheel disc brake conversion we have our own brand for $1149 for manual or $1249 for power. We also carry SSBC line of conversions kits if that is more attractive to you. So if you have any questions or would like to discuss this further please let me know.

Thanks
James

James From
PST Marketing
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Ext 316
jfrom@p-s-t.com

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[Juan Veldez]

The weakest link on a chain is always the one that breaks first. Take a real close look at the damaged parts to try and determine what let loose first (avoid the marks created by the drive shaft hitting the pavement). Could be a bolt backed out and allowed the universal joint to release, the u-joint itself, drive shaft might not have been installed at the correct angle, something inside the rear bound up, etc. But sounds like lighting 'em up and having the tires "catch" pushed something to it's limit. Did the "ticking" noise come from the rear end? Let us know what you find.

 

[challenger6pak]

Put girdles on it instead of the u-joint straps. I was in a Road Runner that did the same thing a few weeks ago and everything was new in the car. It hooked up real well and broke the straps. You most likely had a damaged one that was doing the clicking. The safety loop is a good investment but you still will break the straps.

http://www.moroso.com/catalog/categorydisplay.asp?CatCode=44012

 

[Juan Veldez]

Agree with using the "girdles". Moroso had them made out of T6 aluminum when I was a kid, assume they still do, and other companies would also.

 

[mopar70]

How do I know what size u joint I need.

 

[moparleo]

What is your cars history as far as the driveshaft/u-joints are concerned ? Any work done recently ? This will help you make sure it doesn't happen again. Is this a real high torqueing engine or pretty much stock. New tires or wheels recently? Everyone is correct in recommending u-bolts instead of straps, but it is still unusual for the straps to fail. A drive shaft loop is an excellent recommendation for anyone out there. Parts do fail.

The 2 u-joint sizes are the "7260" 2 1/8" ID and the "7290" 2 5/8" ID .

 

[mopar70]

Bearing Cap Diameter (in):1.078 in so its the 7260.

 

[mopar70]

Well its a small block car with a big block and a rear end swap to 8 3/4. The big block has a lot of torque and the straps never failed one side the bearing cap exploded. I was at a light and just stomped on it in first after a couple blocks I heard a loud snap and when I took a left turn the drive shaft fell.

 

[mopar70]

So when I went under one cap was still in the strap and the other strap was missing a bearing cap and was bent.

 

[moparleo]

Yoke may be bent now. Good time to replace with a u-bolt type yoke and drive shaft loop.