After some tuning of my C3 yesterday I took the car out for a quick spin and the left half shaft decided to disintegrate with the rest of the car. Apparently the outer U-joint broke first, letting the half shaft rotate freely and finally locked between the shock absorber and the trailing arm. As a result, ripping the inner eyes open and broke the shock in two pieces. It happened during a power shift from 1. To 2. and a few meters of wheel spin. It seems like my 400” liked getting the 20 degrees of mechanical advance back again and was pulling quite strong until the mishap.

My question is, where do I find some stronger U-joints to go with my new 3” half shafts and stronger yokes?


A few pictures:








Thanks in advance and regards from Denmark

Karsten Horn

 

HOLY COW!!!! I think that shock absorber saved you even more damage. We would be interested in hearing what happened....speed, etc???

 

Have a look at the scuffing on the battery compartment. I think that you're lucky that the damage was so minimal. Shocks ar relatively cheap.

Looks to me like the half shaft let go first, not the u-joint, not that this makes much difference. Sounds like your 400 is running well!

By the way, I love the grass on the last pic. Nice touch.

 

Same story- get it running good, then the weakest part shows up. Fix that, then the next one, then the next one, then.......


Glad you got away without more damage. Others have had the same thing break and been many times worse

 

This is a pic posted by another forum member last year.....maybe he will jump in and comment...
spicers are a good choice for u-joints...

 

Tom's differentials is the place to find heavier duty components.

http://www.tomsdifferentials.com/

I think I'd sandblast that piece up, repaint it, mount it on a nice hardwood backplate and hang it on the wall like a trophy.

 

Had that happen on the drivers side also. Mine was aided by the use of drag radials though.

 

You had a U-joint failure to begin with. It appears as though the joints were the kind with a zerk grease fitting. They also are a weaker joint, because of the drilled out grease passages. Buy good brand name, greaseless joints [Spicer, Dana, etc.]. After the U-joint failed, the shaft got itself bound up to the point that the yoke broke at the cap. That was secondary damage, and you just need to replace that yoke end. You probably should replace that half shaft, unless you can get it checked out for possible cracks, straightness and balance.

 

What is that!? Is your frame busted?

 

looks like a bend brakeline

 

My question is, where do I find some stronger U-joints to go with my new 3” half shafts and stronger yokes?

Karsten, talk to Steve at Drag Vette and you should be able to get what you need. He will sell you half shafts with Spicer u-joints already installed if you like. http://www.dragvette.com/

 

WOW! The forces involved on either end for that to have happened are amazing. That's like something of off Myth Busters

I had a similar accident on my old '82 only my drive shaft let loose at the dif due to human error while installing new u-joints...don't ask. Nice chunk out of the battery box. Lucky it happened in my driveway.

 

Fort wayne clutch
Look halfway down this thread.
http://forums.corvetteforum.com/show...ght=fort+wayne

 

No - This:

 

That's the edge of the frame at the trailing arm pocket.
Mike

 

Thanks for all the good advice, in the short run, the car will go back on the street with some 3” half shafts from a CBB together with Spicer U-joints. In the long run I will purchase some parts from Toms in order to make the driveline bullet proff. At the moment I have no more than 400 hp if I have that much but the engine is going to get stoked this upcoming winter with new heads, cam, AEM fuel injection so in the long run I need stronger parts.

As people have mentioned, I have been very lucky that I did not break more parts but still, the worst part is keeping the car on the road when it happens. As it happened, shifting from 1. to 2., I was only going about 50 miles an hour so the rear wheel steering could be dealt with. To illustrate how much, I was compensating about 180 degrees on the steering wheel just to keep the car at a strait line until I got it stopped. The wheel went all the way up in the wheel well and the inner side of the tire was rubbing the outer part of the main frame.

Everybody with 35 years old drivelines should inspect/replace all their U-joints simply as a safety measure – Going the Spicer route with all the 6 U-joints would set you back no more than 150 bucks. It is a cheap insurance and the consequences of a broken half shaft is literally a car out of control due to rear wheel steering when the tire disappears all the way up in the wheel well.

Yet again thanks for all the good replies and now onto breaking the next in line weak link


Regards
Karsten Horn

 

This is where I and others have bought the 3" half shafts with the spicers with flanges, you can't beat their price...

 

Hi Rich,
Yup that was mine, and now fitted with a pair of Denny's Nitros Ready shafts.

Safrs3, Although its still sitting in a corner of the garage it will eventually be mounted like you say.

2Tone82 I was popping the clutch to get a bit of wheelspin when the drivers side rear went over a smooth metal manhole cover on a garage forecourt, I think the sudden loss of friction and sudden reload had a lot to do with it. That was a 3" big block halfshaft BTW!

Graeme

 

Your pic is famous with gearheads out here...

Rich