Moses Ludel I hope this post finds you. I'm in the process of reassembling an NOS 1991 AX15 that was built as a 2wd unit and I'm converting it to 4wd using the output shaft and housing from a used AX15. Here's my problem. The 1/2 and 3/4 syncros that came in the new transmission sit ever so slightly higher on the gears than the ones out of my used transmission, which happen to sit just under flush. So, when I go to press the new gears and syncros onto the used output shaft, it puts a slight bind on the syncros and keeps the gear from spinning freely. The syncros on the used trans were replaced by someone before and that transmissions shifted great. The height of the actual syncros are the same old vs. new, but the taper seems to be off on the new trans syncros causing the bind. Is this normal when for an NOS unit to be this tight or should I seek out different syncros to replace these? Thanks for any and all input, it's driving me nuts on what to do here. My gut says just put all the new parts back in and let the trans break itself in, but my brain says not to listen to my gut lol. Please help!