Got LS1?

Last few days I've gotten a vibration from the underside of my car that goes, as best as I can explain it...whap, whap, whap when the car is above 30 or so MPH. At first I thought it only happened in 5th and 6th, so I thought tranny$$$$$$$. More evaluating revealed it did it in 3rd and 4th too. Tells me it's the rearend. I 've had issues with the pinion nut coming loose about a year or so ago and finally lock-tited it.....no issues until now. I tightened the pinion nut to 50 ft lbs, no play back and forth, and still the sound is there. I also visually and hand checked the play of the u-joints, and they seemed good.

I had a similar incident before, but a more intense sound and vibration, when my last set of gears broke a few teeth off the pinion. So this morning I opened up the rear end, hoping to find a broken tooth or two and nothing was broken. No metal shavings or anything, and as far as I can tell even wear on the ring & pinion. I checked if the end cap bolts were loose, along with the bolts holding on the ring and none were loose. I did find the set pin/bolt for the pin that goes through the differential loose, wasnt backed out but I could turn it with my fingers. The pin wasnt falling out, it was just loose enough I could twist it back and forth ever so slightly with my finger tip. I tightened it back up.

Before I button the rear end up I want to make sure I covered all bases. Could that pin have caused the issue, or is there something else I should look at. Also I had both back tires off the ground to rotate the ring & pinion for inspection.

Thanks

wrencher

iTrader: (2)

Does the noise stay with vehicle speed? Then it's in drive shaft or the the rear end.

Got LS1?

I can shift gears while maintaining and it's always there. I also found my Tourque arm bolts weren't anywhere near as tight as they could be. I tightened 'em and am closing up the rear and take it for a test ride.