Had the Dreaded U-joint Failure Today...On the Freeway

[JAS]

Yes, so it finally happened.  I have heard horror story's on this my whole life and it finally happened to me.  Scary, but I'm alright.  In short, the driveshaft is toast and of course the u-joints and straps.  I figure this is a good time to do an upgrade to something beefier as well since I might eventually put more power under it.

What are all the suggestions for the 1970 Challenger I.E. driveshaft, u-joints and yolk that you guys recommend?

Thanks   

[brads70]

Well the bright side is that it was the rear that let go instead of the front. Did it do any damage to the floor?

[JAS]

Hi Brad, I didn't thoroughly inspect the floorboards yet as I just removed the bent driveshaft to get it pushed back in the garage, but I think everything is OK.  So looking more at this, I see Dr. Diff has a Strange Engineering driveshaft starting at $330 with forged yolk and options.

I assume that I have the 45.60" length now with the 7290 type yolk, but that is not verified.  It's a 383/727/489 combo, so that is what I am going off of.

Any thoughts on the 7290 as opposed to the 1350?  Benefits?

[Cudakiller70]

Have the "Strange" drive shaft from Dr diff.
 Strange will give you specific points to measure from for your new drive shaft. The previous owner of our car had the same thing happen. Turns out he had the wrong length drive shaft. Our new one is longer than previous. Upgraded u joints as per Dr diffs recommend.

[JAS]

Thanks for the reply.  I was looking at that one online and saw that it was $380 with the 7290 rear option.  Not bad really considering the quality there.

[Topcat]

Back in the 80's, I was driving north on I-5.

There was a big freight truck right on me when it broke loose.

Was really scary. Thought I was a goner.

[60K T/A]

Any reason why you think the u joint failed?

[shadango]

Have the "Strange" drive shaft from Dr diff.
 Strange will give you specific points to measure from for your new drive shaft. The previous owner of our car had the same thing happen. Turns out he had the wrong length drive shaft. Our new one is longer than previous. Upgraded u joints as per Dr diffs recommend.

Seconding this -- its what I did too...Dr Diif/Strange rocks.

I have from time to time thought about installing loops.....figured it was overkill for my car...but I can imagine this would be scary.

[blown motor]

So the drive shaft loops would contain the drive shaft if the U joint lets go? I assume there would be two, one just behind and one just ahead of the front and rear U joints respectively.

[Cudakiller70]

So the drive shaft loops would contain the drive shaft if the U joint lets go? I assume there would be two, one just behind and one just ahead of the front and rear U joints respectively.

Mounted in front, but some in multiple locations to contain the drive shaft. If your front u joint fails the drive shaft can act like a pole vault.
http://www.moparts.org/Tech/Archive/shaft/6.html
http://www.manciniracing.com/bofrdrlo.html

[JAS]

Got me a 3.91 chuck for now

[brads70]

That should be fun around town. It will feel like a different car! 
Order new rear tires now! 

[jimynick]

That should be fun around town. It will feel like a different car! 
Order new rear tires now! 

Yep, AND a trailer hitch for the tanker trailer you'll need, to go more than 100 miles. I had 3:91s in my Valiant and it ran about 37-3800 rpm at 60. Pass most everything but a gas station. Have fun. 

[JAS]

Mileage is of no concern to me but thanks for the concern.  I think I got a good deal on it.  Fully rebuilt with clutch Powr Lok and crush sleeve eliminator, new everything and powder coated for $975.  Most run in the  $1300 range with that type of equipment.  I also got a 12 month warranty too.

[dodj]

Mileage is of no concern to me but thanks for the concern.

These cars are about fun, not mileage.