One wheel burn out problem

I have been told clutch packs but does anyone else have an opinion on it. My right wheels leaves a nice mark but no left mark at all...The left spins I've been told but doesn't as much as the other at least not enough to make a mark. I have a 4r70w too, so maybe something else is wrong, I dunno. some one help, it never used to do this! I saw an add in MM&FF for heavy duty clutch packs, should i get these and put them in?
~thanks
Tony