AutobahnRacer

For those of you frustrated by the constant repairs and maintenance required to enjoy this sport 'at the limit', here's another story for the record books:

On October 29th I had my car delivered to Autobahn CC. It was in the shop for repairs due to an engine bay fire during my October 1st GT RACE - see video and story on previous post:

http://forums.corvetteforum.com/auto...tober-1st.html

Black Dog Speed Shop came out for support for nearly the full day, and the car was running great. Nearing the end of the day, my buddies from Black Dog called it a day, and headed home. I had 2-sessions left, and decided this might be it for the season, so I pushed ahead. Next session was much like the earlier sessions . . . no problems, just a grin from ear to ear, and having to watch the clock until the next and final session.

A couple laps in, and I'm tearing it up (literally in hindsight) down the back straight. As I shift from 3rd to 4th, I'm guessing around 100mph, the shifter EXPLODES in my hand, and the drivers cockpit fills with white smoke. TWO FEET IN, and I turn the motor off, coasting to a stop half on the track, half off (I avoid the grass to lessen the chance of another fire). My assumptions were either a MOTOR, TRANS or DIFF. None of those were good, but some better than others.

TRY DRIVE-SHAFT and TORQUE TUBE:

The Drive-Shaft is SEVERED - never seen anything like this before!


The Torque-Tube was blasted: The donut seems to be the cause of smoke in the cockpit:


I'm certainly open to a discussion, and thoughts on how to prevent this in the future!

0Randy@DRM

Replace them often.

Randy

sperkins

Jason

Warm fuzzy huh?

96CollectorSport

We see the damage to the torque tube was that the only piece that failed?
The input shaft still seems to be attached to the driveshaft so the doughnut was still holding things together right?
What kind of shape is the rest of the driveshaft in?

What it looks like to me is that the torque tube broke at the weld, we've seen torque tubes crack in the past but I haven't seen one come apart so suddenly and completly like this one. Usually it's an issue with the doughnuts or the driveshaft, but in this case those pieces seem to be intact. Glad you weren't hurt!

96CollectorSport

Randy replace which part? Torque tubes, driveshafts or couplers?

varkwso

The whole assembly...I have parts and pieces of 5 or 6 in my barn.

0Randy@DRM

All of the above.

Rubbers start to go and it starts the process of destruction.

The tube it self has a few welds on them, over time they do "work harden" and fail. The tubes themselves seem to do well until something like this happens.

Randy

L98Terror

That is the exact same way I ended 2010 season at Autobahn with a rubber coupler failing and ballooning my torque tube it was just shy of coming appart like yours did.

You can buy solid aluminum piece to replace the rubber ones, mine had one medal and one rubber, it will get two aluminum ones.

96CollectorSport

I guess I can see the reasoning behind replacing the couplers from time to time as well as the driveshaft. But I wouldn't think that the torque tube would get brittle and fail. I can see if there was more force on the torque tube, but I never thought that the torque from the engine would cause it to spilt in half.
So would solid couples be better or worse for this? The solid couplers would keep the driveshaft from "whipping", but again is that better or worse for the driveshaft?
It's not like you have these things out all the time so it's tough to know when it's time to replace.

Short-Throw

Motor upgrade = driveshaft upgrade = Run Forest Run.

On the plus side, your car will be stocked with fresh components on the big ticket items.

Should be a fun 2011 for you Don!


Mike

0Randy@DRM

Ask 10 people and get 10 different answers

Everything fails, work over time

Randy

sperkins

I have to pull mine this week due to a bad vibration. I've been considering solid in the rear and poly/alum hybrid in the front.
I figured that it needed at least one side with a little flex to absorb any harmonic vibrations. There's a lot of rotating stuff inside there. Is my thinking right?

Pumba

Are you really surprised that your driveshaft coupler failed? By the looks of it in the picture, it had been failing for some time. The disintegration of the coupler is what sawed the torque tube in half.

Is that a stock aluminum driveshaft in the photo?

There have been many posts on this forum about the problems of the stock rubber couplers and the stock aluminum drivehsaft. What made you think you could run those components in a serious road race Corvette?

If you want to avoid those types of failures in the future save your money and purchase a Pfadt Racing carbon-fiber driveshaft with its solid couplers. End of problem!


Oh yes, change the title of your post. Your shifter did not explode!

-

dvandentop

damn bet that was a hell of a racket for sure!

glad you are ok and no major injuries besides the car again.

makes me want to tear mine apart over the winter to check it out

Racer-38

Was your experience something like this?:

http://www.youtube.com/watch?v=YRcydiI7k1E

Everything in my car is solidly mounted. I'm on my 4th torque tube and I expect it to go anytime now.

varkwso

The TT housing gets "peened" where the driveshaft bearings ride. Vibration gets motion going. Hard bearing and softer aluminum.

I no longer use solid couplers since I think harmonics will happen and something has to absorb it.

OKsweetrides

Sorry to hear about your DS.

How many miles did you have on yours?

@Randy@DRM,
How often should a carbon fiber driveshaft with a single aluminum coupler be replaced? It's mostly just the guibo(sp?) joints that crap out right?

I only went with a solid engine mount on the passenger side, so theres still some damping action to reduce the vibrations.

AutobahnRacer

Are you sure you're not the LION KING himself? Wow!

Change the title of your post? Really? Do you have a sense of humor?

FYI:

1.) No, I'm not surprised the coupler failed. This is only the 2nd time in 4-years, but it did fail in such a way that my race shop (Black Dog Speed Shop) hadn't seen in the past.

2.) What made me think I could run those components in a serious road race car? My car has been an evolution from street to race for several years. I didn't plunk down $ 50,000 to convert it overnight, and MOST of the components have been upgraded. Unfortunately I upgrade on an 'as needed' basis.

3.) Buy a Pfadt drive shaft, solid couplers, problem solved? My drive shaft had been converted in April 2010 to a solid (billet) coupler on one end. The part was in very good condition at that time. I have several Pfadt parts on my car, and Aaron has been helpful, most recently with his Competition Sway Bars. Those were added as I was getting excessive roll-over, and tire wear using T-1 bars. My shop has suggested solid couplers on both sides, and my Thread Post was intended to either confirm that or solicit other options.

Pumba, read all of the replies above and below yours. The tone is alot different than yours. Regardless of your knowledge and/or experience, you sound like an a-hole.

Best of luck!

L98Terror

What happens is when that coupler gives it expands and the pieces of medal and rubber beat on the inside of the torque tube causing the torque tube to balloon(it is actually cutting through the torque tube), depending on how fast you shut her down and how fast she was spinning will determine how much damage to the torque tube.