Where are you transferring to? where are you transferring from? What are your grades like?
Generally, I think that retaking the LSAT wouldn't help much, the LSAT measures how well you'll probably do in law school, based on your ability to reason.
Your grades measure how well you DID in law school, and I think those would tend to outweigh the new LSAT score.
But, retaking the LSAT couldn't hurt I guess. Especially if you nail it.