QuinnC30
Junior Member
Hi everyone, forgive me as this is my first post, so for some time i've been having some shifting trouble on my 2016 1500, she's a 5.7 4x4 zf8 , basically i would have the 3 to 4 gear neutral shift/shift flare, but if i would shift to reverse before i do a 3/4 shift it slammed into reverse, but if i hit reverse before a 3/4 shift it wouldn't shift flare, looking at the adaption values in my scan tool, i was getting 0 for fill pressure on the E clutch im not a transmission guy by nature but i did go to school for Auto tech, and not afraid to dig into this sort of project, so i figured i would try and see if i could find anything wrong in the valve body, before i just open up the whole trans, so i got specs from Sonnax, bought the vaccum testing equipment, and the Main Pressure Regulator valve, actually only held -8InHg can see visible scoring in the bore, so i got the mounting fixture for the valve body, and the Sonnax reamer, pin, and guide and reamed out the hole, the centering pin made it very easy to line up the reamer, but mind you this is my first go at this and i think i could have gotten a better surface finish, i used a constant stream of A9 cutting fluid, after hearing many mixed reviews i opted to install a Zip kit as well, after vaccum testing post install the Main PR valve measured -20inHg at the center port, and -23 at the other two ports, and everywhere that was installed with new o-ringed end plugs tested just as well as the factory plugs, the rest of the valve body had some variation in vacuum numbers from valve to valve but everything else is well within spec, i have videos but can't seem to figure out how to get them to post haha, i have the truck back together and installed a PPE deep pan, shifting was immediately better, E clutch is measuring 300 mbar now, and more importantly no more shift flare, and no more slamming into reverse, i'm not an expert on these transmissions or reaming but if anyone sees something i could have done different please speak up!
