Ok, I've gone thru a ton of transmission threads and I'm still not completely sure. My 95 does do the slight shudder or more like a vibration when shifting from 3rd to 4th under light throttle sometimes. But when I accelerate under light throttle when it's in 3rd, it's more like a jerking/shudder but does not slip and the rpm's are steady. The more gas I give it when it does this, it quits doing it. It's not throwing any codes and the od light isn't flashing either so I know the engine isn't cutting out. The trans doesn't slip in any gear at all and shifts good. I had the trans serviced two months ago and was told everything looked good inside, no sludge or shavings in the pan, the fluid was not burned and was still red but the guy put dexron III back in it. It was fine up until a couple of weeks ago so I just drained it again, including the convertor and put Mercon V in it and it's still doing it. So do I need a convertor now?