About my car- completely stock 2002 Zo6 with 95,000 miles. Only problem (before today) was it had a bad 1-2 synchro. 5% of the time it would it would grind on a 3 to 2 downshift, and would always grind when trying to shift it into 1st above 5 mph.

Today I was headed to work and driving like a grandma. 5 mins away from home I got up to 60 on the freeway cruising in 6th gear and BAM! What sounded like (really bad) constant gear grinding slowed me down to a stop. After towing her home I found my differential cracked through badly, and no signs from the outside of a cracked tranny case.

I could move move through the gears with the car off and when it was hand pushed it would thud (grind, etc) every 3 inches UNLESS the clutch was pushed in, then it would be smooth. I started the car in neutral, and when I let the clutch out and it moved and stalled as if it had been in first.

My thought was the tranny locked up which in turn broke the diff, but when I got home and drained tranny oil, it was clean with absolutely no metal shavings in the oil?

Obviously my diff is toast, but what would've caused this? Could it still be tranny even though it has clean oil? Maybe clutch? And why did it stall when I let the clutch out in neutral? I am stumped.

 

wow . i wounder if the spider shaft somehow let go in the differential.

 

Sure you weren't driving like the little old lady from Pasadena? ��

Mark.

 

I cracked my differential driving down the highway just like you. Although mines was not cracked as bad as your's. I was still able to drive it home. Everything was working fine on it besides the crack of course. Before it imploded like that there was some light grinding noise intermittently. My guess is something broke loose inside. Cost me $2500 to get it replaced with a new GM unit in case you were wondering.

 

I recommend a DTE, or ECS trans/diff brace.