Cool!!! That's what I'd hope for too, at least to see some real world conditions. DS usually see some serious RPM's too.

 

If I had to describe it, it'd be just that. It hummed like a *****. Yea, it's puts a load on it, not just a free spin.

As far as an update... I finally got my truck up to 105mph w/o vibration (open interstate, of course)! I can't wait to get to the track with the tune worked out, but I gotta get rid of the shuddering converter I have. That's the next thing to get done, then and Eaton and new gears. Seems like the GM POSI & 4.10 gears (used) grind while turning at low speeds.

Hey, Kev... Trailer that truck down here, and get Jim to hook you up. Then, you can run that truck down to NPR for some cool weather runs. I'm hoping the weather will be favorable on the 5th of Jan. Today sure is a great day.

 

They didnt spin it up like that on mine. Perhaps thats the problem. He just put it on a Lathe and at low speeds, he put a bunch of dial indicators on it and never changed the speed....This is starting to make me think.

 

when mine was done (two piece) it was on a long lathe. There was a brace for a center section, and mounts at both end. It was spun to 7K and there were flashing numbers at both ends, kind of like a timing light. It would flash the sized weight that it needed, at both ends. He taped the weight on with masking tape, and spun it up again. If it was off by a hair, then he'd slide the weight side to side and then run it up again. If that still didn't work, then he had smaller weights to add. When the shaft was balanced at "0" they were spot welded back on . . . and rebalanced again. I had 1350 yokes/ears/u-joints and 1 ton rated splines added for the slip yoke (2 piece shaft). All of that with sealed Spicer u--joints. There's a considerable difference in size.

 

That's what the guy did with mine. Showed me the dial indicator. If it showed a steady indication, it needed weight for balancing. If numbers jumped all over, it was good.