I have a 2005 manual Z51 coupe with 10,000 miles. In the last 200 hundred miles it has developed a grind when upshifting hard or any downshift to 2nd gear. I suspect a worn or broken syncronizer. I will be contacting the dealer for service tomorrow. Anyone else experiencing this problem?

If it ONLY grinds on a hard/quick upshift, the synchro ring may well be worn, or the synchro assy. may have other issues.
If you had a problem with every 1-2 shift(or 2-1 downshift), there may be a broken ring.

I have to assume the fluid has not been changed, with that mileage, so it's probably not that, but the wrong fluid can cause this problem.

I haven't heard of any abnormal wear/trouble with these trannys yet...

The dealership confirmed there was a problem. they ordered parts to replace the synchro and the second drive and driven gear. Upon disassembly they couldn't remove the mainshaft. GM authorized a complete transmision replacement. I still am curious as to the fault, maybe a seized bearing. I pick it up tomorrow. A major winter storm predicted for the midwest.

Thanx for the update! Let us know how the new one werks!

I have only logged 200 miles on the new unit, but spring is near. BRRRR

|UPDATED|2/5/2007 11:07:50 PM (AZT)|/UPDATED|