New Sierra Transmission Clunk

[ze3bar]

I have been having issue with mine since the day that I bought it. Terrible up-shifts up to 4th gear, harsh 3-2 downshift. It has been the worst experience. I bought the truck with 14 km on it. I drive very nicely. It has about 35k on it now, and I read somewhere that adding Lucas transmission fix to the 6L80 seems to smooth it out so I tried it and it seems to be working. My issues have been worse when cold, and this morning when I drove my truck it was much smoother than before. 1-2, 2-3, and 3-4 were smoothed out and 3-2 didn't throw me forward as usual. I don't know if this would help anyone else but I thought I would mention it to see if someone else is willing to try it and confirm my result.