I had a severe shimy in my 3500 while towing a 3000 lb. trailer downhill and braking on sharp turns. It was so bad that I almost couldn't control it after braking 2-3 times in those conditions. Replaced with regular pads and installed slotted dimpled rotors (I think they were EBC) and it almost totally fixed the problem. Now I only get a slight shimy when going down steep twisting roads with many sharp turns where I have to apply the brakes in sucessions of 10-12 times in a short distance without a cool down period (like coming down hwy 36 from Chester to Red Bluff). And yes I do shift down to second and sometimes first gear but sometimes the road is just too steep and twisting to hold without braking a lot. I normally push the brakes fairly hard long enough to slow down way beyond the gear I am using and then let them cool while the engine speeds up to about 3000 rpm and then brake again. My engine can hold a 5% grade in third gear without braking. Anything more than a 7% grade I use 2nd gear and anything more than a 9-10% grade I use 1st gear. I also have brakes on my trailer.
