My NSS is leaking pretty bad, enough to run down and drip. Last time I had it in the shop the mechanic replaced the o-ring with a generic one but I guess it's worse now. It's not the correct transmission for a 99. It's got an 01 46re with the square nss with torx screws holding it in. I only have a factory manual for a 99 so I don't know if there is any special instructions for installing the square type. I couldn't find any videos online either.