Every wrangler with more than 15,000 miles that I have driven, are finiky going into second and third. You have to shift slow and let the synchros work, or they like to grind a little bit. Just take it easy, and shift like it was a big truck transmission. Nice and slow, and you will be ok. Some different oils help, but it will always be there to an extent. Unless your transmission is griding no matter what, I would say its a normal Jeep trans. Wranglers are not known for the best transmissions in the world, but they should hold if you take it easy.