Driveshaft phasing spec
Driveshaft phasing spec After a several year battle with vibrations, I'm getting a new 3.5" aluminum shaft to replace my 3" chromoly Strange DS. I gutted the diff, leaving only the pinion gear. I also lowered the rear end with a jack to line up the driveline to have almost zero degree angles at the front and rear u-joints, eliminating any possible pinion angle vibrations. When running it on jackstands to 130MPH I still get a vibration at the frequency of the driveshaft spinning. I had it rebalanced years ago by Denny's and it was tolerable. Just recently I had a local shop put a 31 spline yoke on it for my T56 Magnum and I asked them to check the balance. It came back to me with 2 extra washers on the rear, he told me it was out of balance. They also told me the balance the DS without the slip yoke attached.... so it's probably out of balance now. I didn't go back there, as they don't seem competent in dealing with racing applications.
Anyways, upon examining the Strange DS here are the measurements I found:
Front runout: 5 thou
Center runout: 12 thou
Rear runout: 9 thou
These don't seem terrible, but the one I don't know about is there is a 1 degree difference between the front and rear yokes.
What is an acceptable spec for yoke phasing?
I'm hoping to report good news in a few weeks when I get the new DS installed. I'm using Driveshaft Specialist Inc from Texas to build the new one. Craig was very knowledgeable and friendly on the phone so they won my business. Also Denny's and the other big names are 8+ weeks now and I don't want to wait that long.
Anyways, upon examining the Strange DS here are the measurements I found:
Front runout: 5 thou
Center runout: 12 thou
Rear runout: 9 thou
These don't seem terrible, but the one I don't know about is there is a 1 degree difference between the front and rear yokes.
What is an acceptable spec for yoke phasing?
I'm hoping to report good news in a few weeks when I get the new DS installed. I'm using Driveshaft Specialist Inc from Texas to build the new one. Craig was very knowledgeable and friendly on the phone so they won my business. Also Denny's and the other big names are 8+ weeks now and I don't want to wait that long.
