Listen to this...what is causing that resonation?

I had the driveshaft balanced and straightened and they gave me new u-joints. I put it all in and it made the noise, so I did a 180 turn and no difference.

I have seen this happen in the past with u-joint straps too tight, but I doubt that is my problem here. I tighten the strap nuts until the lock washers just flatten, and no more. I have no way to actually measure it with the current tools. My torque wrench is 1/2 drive and too big to fit in there. But it is just barely snug with 2 fingers.

 

on the u-joint straps use blue lock tite on the nuts. i tighten the nuts down by holding the drive shaft with one hand and using a wrench. i tighten it till i cant hold the shaft from turning. this method should not damage the caps and will make sure the u-bolts dont back out.

spools and mini spools will not cause resonace. as stated the diff not being set back up can cause a noise.

usually an ossalating resonace is caused by drive shaft being out of phase. this can be caused by the pinion angle not being close or the same as the transmission out put shaft angle. idealy you want the pinion angle to be 2 degrees down from what the trans angle is. when the diff is under load the pinion has a tendency to point up. the theory is that it will match the trans angle under load. the angle can be effected by alot of things. leaf springs that have a different mounting angle than origanal. a colapsed trans mount, or bad motor mounts. caltracs bars may be able to cause this also if they are too tight on the leaf and pushing the pinion down.

 

I was wondering that too... I'm thinking it might.

 

45 the exhaust out the side instead of turned down. Mine exit under the car but facing out instead of down. I will be adding a down turn but mine will be facing backward instead of down if that makes sense. Exiting in front of the rear wheels and facing back.

 

I remember those Fox bodies. Good friend put a walker dynomax kit on his for one day. Then he went and bought factory parts. It was worse than our Mavs.
Interesting idea with the dumps. Mine are welded on though. Go figure.

 

Different car,different firing order,different harmonics.

 

How do you get a one piece driveshaft out of phase? The only thing you can mess up is the front yoke on a ujoint swap and thats minor. Out of phase is huge in 2 piece units but I think I'm missing what your getting at with our one piece.

 

a one pice can be built out of phase. thats where the ends are not lined up correctly with each other. i have seen it. the other thing is the u-joint operiating angles need to be the same or as close to each other as possible.

 

Off topic but an old school SBC and a ford 302 have the same firing order. Chevy just numbers the cylinders differently than Ford.

 

Since you got it off topic with chevy firing orders...I was reading an MSD writeup on the 6A box installation, and they said something about the 2 and 5 cylinders being next to each other, and I got a bit confused.

So how is the Chevy firing order? are 1 and 2 where our 1 and 5 are?

 

Look at this, maybe it will help.

http://www.joby.se/corvette/misc/firing_order.gif

I believe it would have said that 5 and 7 are beside each other, like 7 and 8 are beside each other on a Ford.

 

Wow! They even start on the wrong side!!!

Dumb chevy guys!

And you could be right about the MSD instructions. I don't recall exactly what the numbers were, but they didn't jive even close to how our motors would fire.

 

Not only that, they put the dizzy on the wrong end of the motor!

 

Scott!!! Ive figured it out!!! your Flux capacitor is out of phase with your douotronic inverter.Just readjust it to 1.21 gigawatts and you will be good to go!!!

NO NO dont thank me...Just tell me to get lost

 

But I just replaced the Flux Capacitor AND the douotronic inverter as a kit. They should have been calibrated at the shop! I guess I can check it with my multigigometer, if it still has a good radiation charge...