I have a '02 S60 AWD, the transmission has "issues" delayed shift to drive. shift flares etc. I have read the TNNs with regard to the B4 cover, valve body replacement, TCM software upgrades etc. I am a skilled DIY'er, but pricing just the parts i.e. new valve body, wiring harness and seal kit is higher than what I can buy a later model transmission for. If I were to install a AW55-50SN from an '03-'07 what issues could I expect? will my current TCM and wiring harness work with a later model transmission? Would the transmission need to come from an AWD or can I bold my bevel gear box up to an AW55-50? I am attempting to save the existing transmission, did full fluid flush, added additional transmission cooler and inline filter, have it in the Volvo dealer today to upgrade the TCM and DEM software. I may also pull the B4 cover to see if that helps, but I realize that that may only fix some of the issues. There are around 92k miles on the transmission. I am looking for all options with in my budget.