rockytopper

Well it has been a year and almost 10k later sense I got my ls1 cutlass on the road. This morning the road was clear smooth and straight. I decided to push it and see what see would do. I have autometer gauges the speedo only goes to 120. I hit 120 quickly and started watching the tac. I reached 5000 rpms in 3rd when the loud explosion hit the floor pan and blew my coffee mug into the air. The drive shaft let go. According to the speed rpm calculator I was at 130 mph. The car was running smooth and pulling very hard. she had a lot more in her. I found the front half of the drive line. I'm not sure if it came loose at the axle or twisted in the middle. The entire thing was brand new. Luckily all appears to be ok except I need another custom drive line made.

pist0lpete

iTrader: (3)

Sounds like you dodged a bullet there. That would have scared me pretty good thats for sure. This was all on a closed course right? lol

NemeSS

iTrader: (127)

that sux
did u have ds loop?

rotor vs. piston

iTrader: (3)

That's scary that a new drive shaft would do that. I've been 130mph in my DD, I would have **** bricks if that happened at that speed.

Stu Cool

iTrader: (13)

Rocky, you need to read these about Drive Shaft Critical Speed before you shop for a new shaft.

http://carcraft.automotive.com/10487...ips/index.html

http://www.wallaceracing.com/driveshaftspeed.htm

Glad you and the car survived that

Pat

V8Rumble

iTrader: (9)

OK, Rocky, we're definitely glad to hear that you made it through that one basically OK. But now that you've had a bit of time to grab a drink (& change your shorts!) it's time to get out there & find the next-weakest link!

Actually though, I'm also wondering - did you have a driveshaft loop, or were you just a bit lucky?

the_merv

iTrader: (88)

Damn.. if I felt that I would think I got hit by an RPG..lol

rockytopper

Thanks guys. Stu that was very informative much appreciated. The drive line twisted into about 12 inches from the front yoke. Not sure if I had weakened it from the numeous hard launches or if it reached it's critical speed as discussed in the links STU provided. I am in the process of getting a new one built. The car does not have a ds loop. The original drive line had a step down very close to the rear yoke. I never figured out why. I am wandering now if it was not designed to fail at the rear so that the drive line would basically just exist the car with not enough left on the rear end to catch the ground and cause a major wreck. I am indeed lucky the drive line just sheared and bend the u bolts at the yoke and left the car with out incendent. The drive line I had built did not have a step as most drive lines do not.

deelong4002

iTrader: (8)

man my uncles buddy died in his 3rd gen cause his drive shaft let loose. Threw him off the road at about 130mph

holley505

iTrader: (1)

LOL. I hope you where going 130 mph with HOT COFFEE in the Car? You may have wrecked for sure.

BTW nice car.

Time for a shaft loop

rockytopper

It has been almost 3 months sense I had the driveline decide to exist my ride. I am just now getting it back today in working order. It damaged the rear end yoke and pinion gear. I sure have missed my baby. It took awhile to locate a good used pinion and ring gear set. They do not offer them in a 3.08 ratio anymore.

Any of you guys planning to attend GoodGuys this weekend at Texas Motorspeedway? Apparently you get to drive on the high banks from 5-8 pm at the track. I plan to be there on Saturday around 1 pm. Hope some of you locals can make it out should be fun.

ls1nova71

iTrader: (4)

I'm not local, but I plan on being there in my '33 Ford. Good to hear you got your car going again.
Oh, and one other thing, they won't let you do 130 on the track...... I got kicked off of the track at the Goodguy's show in Kansas several years ago for doing about 115 in my Nova, the little motorcycle cop guy on the track read me the riot act for going too fast on a racetrack! LOL

pist0lpete

iTrader: (3)

You gonna have your car out there? I plan to make the trek from Stillwater down on saturday. Hope to be there by noon if not sooner. I won't be bringing the chevelle unfortunately as the tranny appears to be going south.

rockytopper

Yes I plan to have the F-85 there, I wanna circle the highbank in it. I'll probably be in the you gotta drive them section plan to be there around 1 pm on Saturday. Hope to see you there Pete.
Rocky

pist0lpete

iTrader: (3)

I will keep my out out for ya man!

John McGraw

Rocky,

Glad you got it back going!
When I was playing with the suspension height on my Chevelle, I noticed that full compression (or in my case, deflated airbag), would result in interference between the driveshaft and the rear floor brace. My guess is that this was why they necked the driveshaft down. I ended up raising the tunnel for the entire length of the car. I had to cut on it anyway to shoehorn the 6L80 trans in, so i just went all the way back. I am considering installing safety loops front and rear on the tunnel.

Regards, John McGraw

pist0lpete

iTrader: (3)

That an interesting point you bring up John. Another member on the Chevelle forum had similar issues although his was static dropped not bagged. It appears that once you go low enough it is impossible to get a good driveshaft working angle without modifying the tunnel.