And yes im posting this is "Engine & Drivetrain" instead of "Maintainence" since most users who would be interested in this swap are most likely doing it for the added performance benefit. Also, this is tC specific so it seems to be a better fit here. Mods, move as you see fit but IMO, it should be in this section.
The tC trans is interesting since the "fill" plug is parallell to the ground and quite low on the car making filling very tricky. The best way around this is to use one of the other plugs on the tranny that just so happen to be on top of the case within easy reach. The reason I am starting the DIY with this step is that you want to make sure you can get fluid back into the trans BEFORE you drain it. Nothing is worse than draining the fluid only realizing you have just stranded yourself since you cant get any fluid back in. The easiet place to refill the tranny from is through the reverse sensor on the top of the trans case located here:
You will need a 1&1/16" socket and a 10" extension in order to get this out easily. I also found that removing the bracket located nearby made getting to everything a lot easier:
You can see how much more room there is with the bracket and wiring moved away:
Remove the plug and loosen the sensor but dont remove it completely yet. Go ahead and snug it back down for the time being. This step is just to make sure you will be able to refill the tranny with fluid.
Now comes time to drain the old fluid. I made the mistake of removing the reverse sensor first which let air flow easily into the tranny form above and was greeted with thick smelly and slimy trans fluid gushing out from the drain plug. By leaving the fill plugs closed, the fluid will come out much slower saving you many many paper towels and gallons of Simple Green. Im not kidding, this stuff REALLY makes a mess.
Unsrew and remove the drain plug circled in green to get the stock fluid out and into a drain pan:
After your fluid has drained, reinstall and tighten the drain plug.
While you are under the car, go ahead and remove the "fill" plug circled in red in the picture from above. We will be filling the fluid from the top of the car but by having the fill plug out, we can guarantee we wont be overfilling the trans. When fluid starts coming out of the fill plug, you know you are good to go.
Go back to the top of the car and remove the reverse sensor and put it somewhere safe. Use a long funnel and fill the tranny with the new fluid. I used just under 3 full bottles of Redline MT90 before I had fluid come out of the "fill" plug.
After the tranny is full of new synthetic fluid goodness, tighten everything back up and make sure your reverse sensor is plugged in. If not, your reverse lights wont come when you are in reverse.
As always, be sure to us jack stands when working under the car. Also I am not responsible if you screw your car up. Im happy to answer any questions so fire away
I felt the car ran smoother and was much easier to shift and get into gear. In combination with synthetic motor oil the car simply runs better and feels smoother in any circumstance. Definitely a must do for any tC, but especially one that is being driven hard and being pushed to eek out as much power as possible.