Appears straight. Based on the sound, I guess its not.

driveshaftnoise.MOV

 

Holy crap are the u-joints bone dry?

 

Rear U joint probably not more than 500 miles since new LS1 drive shaft put in.

Front probably not more than 200 since the tremec was installed. And both still had good grease then.
It was perfectly silent with the 7.5"

 

Unbolt the driveshaft and turn the wheels to see if it's still making the noise. Maybe turn the driveshaft while it's still stuck in the tranny but not attached to the rear to see if it's coming from up that end. Anything rubbing anywhere? Never heard anything like that before.

 

Do you have drum brakes out back? It might be dragging a bit and may need a little adjustment. Pull off the drums and turn it without the drums. My Tahoe's rear drums sounded something like that when I had them adjusted too close.

 

This pic of the right Ujoint saddle shows the tang getting crunched down where the middle of the Ujoint is too wide.

The ujoint measures 3.691" and I was told it was a

yoke.JPG

Rear disk from a 4thgen.

edit
I just touched it with a diegrinder and managed to get it to set down there pretty good. So far no noise after putting the DS back in but that just rolling the wheel. I will probably go for a drive later as the acid test. If it is still noisy I will probably take the yoke and the ds to a local shop

PS, thanks
Keep an eye out for some tire smoke vids soon.. (and this will have an engine audio track, not some lame new age music).

baaawwwaaa..

 

So you didn't get the combo u-joint? I had to get one that was a combo 1310 series for the Ford side then 3R for the stock driveshaft. Yours is probably different on the driveshaft side though.

 

Maybe get the car up in the air, stick it in drive, and then get under the car and see if you can isolate the noise. Definately wierd though, never heard a noise like that. When the U-Joints in my truck went out, they made a squeeling noise like bad brakes do. The rollers in those were ground to a fine rusty powder though...

 

The front U joint had to be a combo (for the tremec C4 output shaft to the ls1 ds). But I figured the back would be a 1330 ujoint.

My logic was "why would someone go to the trouble to build a 9" with 2" wheel studs and then put the smallest u joint on it.?"

But, so much for that. Someone on chevytalk.com said it was probably a 1310 ujoint.