I found that a 10mm Allen key worked on my 1998 Camry. It fit perfectly. Unfortunately, after six years, the thing would not budge. Even my stronger friends could not get it off. So, I ended up taking it to Goodyear and spending $60 that I really did not want to spend. It is now clean as can be and running smooth. It was getting a little rough in the shifting, but hopefully I did no long term damage.