Gabtec

Bought a 2014 Sierra back in September. 6.5 box crew cab, Felt the vibration issue on the steering wheel when it hits 80kmh -100kmh. Did the forced tire balancing and did not help. Replace the whole set of wheels and still nothing. Put on brand new blizzaks now that we're in the snow and still no luck. Brought it back to the dealer a few times to replace a whistling sound in the exhaust and repair the vibration issue. Had their tech test drive it as well and he also felt the vibration at the said speed. Apparently they knew of this problem as being in the gear and pinion being off slightly in the rear differential. They apparently replaced it the first time to no avail. So they re-checked it again and apparently the new one was off too. Replaced it a second time and VOILA! Vibration is gone. Apparently GM Had a problem with the Mould casting they used to manufacture this gear and pinion. But all I know is now the vibration is gone. Nice truck, just too many visits to the shop for me. :-/