redass02gt

my 4r70w makes a weird clunking noise when I use the sct xcal2 tune. When I am cruising in o/d around 30-40 mph and I give it some gas, it sounds like it "clunks" or grinds. stock tune has no problems. I think it has something to do with the torque converter, because it doesn't do this in non-o/d mode as well.

DIVER8374

I know what you all are talking about with the clunk when in o/d and goian around 30-4- mph. From the conclusion that I have come to is that it is normal, it is just the trans being in to high of a gear when going that speed, so when you give it some gas the trans has to get up to speed with the resto fo the dirve line. What I always do is shut off the o/d when I am cruseing anything lower than 40-45 and have no problems. Now that I have the 4.10's in I don't have to shut off the o/d because it is a a highter rpm at thoes speed and I do not have that clunk anymore. Hope this helps, I would just shut off your o/d when going that slow.