Alright, so I've gone through and reassembled the whole SMG hydraulic unit and bolted it all up to the car so here i'm going to post all my findings and info I found in the process. This is not really a DIY guide since it skips a ton of steps but I'm laying out steps which I found to be a bit of a gotcha.
As mentioned in the previous post I used an O-ring and seal kit I purchased from http://MLReng.com
. They normally only sell the SMG pump motor kit, but I emailed them and they also were able to provide the o-rings for the shifter hydraulic unit as well.
So first off I purchased a brand new parts washer from harbor freight for this job since my old one was really dirty and I was afraid i'd pump some junk into the parts while washing them.
I did a bunch of research regarding what soap would be good to use and ended up using Simple Green, looks like it's even recommended for washing airplanes and airplane parts so it's totally safe on aluminum, shouldn't etch it even if left on for a little while. But it shouldn't be anyhow, since after washing the parts in the washer with some tube brushes I immediately went over to my sink and rinsed them with hot (as hot as wouldn't burn my hands) water then I went over to my garage and blew the parts dry with shop air (filtered). Since I wasn't replacing the actual shifter piston seals I decided it's best not to wash or even touch the seals, so I simply removed and gently poured fresh chf-11s on them just to rinse off any dirt, and just washed the 2 chambers they slide into. When you remove the pistons keep in mind they are directional (or at least they aren't symmetrical). Take note of the shape when you remove them and reinstall in the same orientation.
Also I decided it's best not to wash the actual solenoids in case water got into it and I wasn't able to fully dry it out, in retrospect I maybe should've but I didn't.
At this point everything was reassembled using all new o-rings, I highly recommend using a plastic toothpick to remove the o-rings from the solenoids so as not to scratch the o-ring grooves! Also fully lubricate all the o-rings as you slip them on the solenoids and it's also a lot easier if you start from the smallest to largest o-ring, that way the larger o-ring won't get stuck in the small o-ring's groove. Then just before pushing the solenoids back in don't forget to reinstall the shifter position sensor before putting the 2 rear solenoids (it goes under them), here's what mine looked like after soldering on the new wiring harness, I used some raychem heatshrink on mine, also the wire insulation coming right out of the unit totally fell apart so the very base of the wire was still exposed so I slathered them in some conformal coating and then silicone RTV to make sure no water gets in there.
Just before installing the solenoids apply some of the grease provided and carefully pop them in by applying even force, mine went in with maybe 10-20lbs of pressure, then use some loctite blue 242 or similar threadlocker (I used this stuff from amazon
) on the little torx head screws before bolting them in.
Next step is to install the shift pistons, lube the inside of the pistons tubes and dip the pistons themselves in some fresh CHF-11S and carefully slide them in, then position all 12 o-rings labeled "Shift Cylinder" in my kit (4 larger ones for the shift position sensor and 8 small ones for the piston block) and reinstall the piston block in the same orientation as it came off.
Again use some of the blue loctite on the 12 torx bolts which secure down the piston block as you screw them down.
Before sliding the shift piston block onto the transmission don't forget to make sure all the pistons positioned such that the middle cutout is in between the 2 blocks and rotated around such that the notch is facing down like in the following picture:
Then put a coat of RTV on the sealing face following around the outside of the screw holes and inside of the alignment pins and press the block onto the transmission again using blue loctite on the bolts.