How do I check the tranny oil?
 

I have never owned a car that doesn't have a dipstick for the tranny oil, so I was reading some of the posts on here on how to check it, the "fill" hole on the side of the tranny some are saying is the only way?
I don't have a way of jacking up the car completely off the ground right now and I don't think I can check tranny oil if it's on ramps .

Any suggestions on other ways of doing this ?

The transmission has two plugs, the higher one is the fill hole the lower is the drain hole. To check it just remove the bolt for the fill hole and stick your finger in there to see the oil level.

When doing a fluid change, you drain it from the lower drain hole then fill it from the upper fill hole until oil starts coming out.

Its basically identical to changing the fluid for the rear differential.

^ essentially true. I don't have the shop manual in front of me, so I'm not sure of the exact level... Some cars call for the fluid to be level with the bottom of the top hole, while some manufacturers like it about 1/2" below the hole. The car must be level when doing this, so ramps won't work unless you also jack up the rear to match the height.

Level with the bottom of hole but the car must be "level" to get an accurate reading. This is intended to be done on a lift but if you're doing it in the garage then put the entire car in the air with 4 jack stands.

edit: advice is regarding 6MT.

With the automatic it's not quite so easy, there are three holes, two on the bottom and one on the side. One of the bottom ones is the drain hole and the other is a "Check" hole. To check the transmission fluid you have to start the car in park and then check the fluid using the check hole while the car is running. If fluid drips out slowly it's the right level, if it pours out then there was too much and replace the plug when it starts dripping, if there are no drips you need to add fluid. There may be some other steps in there, My Tacoma uses the same type of automatic transmission (albeit much larger) with the Toyota WorldSpec ATF (WS)/Subaru WS ATF fluid and the transmission fluid check is VERY complex, it requires jumping pins on the OBD port while the engine is cold, then starting the engine, shifting from park to neutral to drive a prescribed number of times which puts the transmission into "Fluid Check Mode" then you have to sit there for 15 minutes and wait while the transmission comes up to temperature, once the transmission comes to a very specific temp a light on the dash illuminates and THEN you can use the check hole to check fluid levels while the truck is in park. It's very complicated...I don't know if the BRZ requires that complex of a procedure...check the service manual it is posted in the stickies in the top of this section.

EDIT: I just checked the manual and yes he Automatic transmission has the same complex procedure as my Tacoma. Requires jumping pins on the OBD port and waiting for the proper temperature after shifting it into "Oil Temp Detection Mode." It's...a pain.

Drain plug
 

Does the brz plug have a magnetic insert? Has anyone know whether GL 3 or GL 5 is best?

GL 3 Is the recommended fluid, but it is an old spec, and not too easy to come by. GL 5 is (typically) more of a rear diff fluid, and may contain additives that aren't good for the synchros in the trans. Some GL 5s are ok, but I wouldn't chance it. GL 4 should be ok to use. I just picked up some Redline MT-90 (75W90, GL4 synthetic) yesterday, and plan on changing the trans lube this weekend. I'm not sure yet if the drain plug is magnetic or not. I'll be pleasantly surprised if it is.

try this

Back to roddy: what about MG gear oil special II?

Did your car come with an owners manuel?

I believe that is the recommended fluid. I remember someone posting that they went to the dealer, and they didn't have it, or could only get it by the pail. To be honest, I didn't even try. I like to run aftermarket full synthetics any time I can anyway. I'll be at the dealership today to pick up a TRD air filter. If I can remember to do so, I'll ask about the MG special II while I'm there.

I can confirm that both the transmission and the rear diff have magnetic drain plugs as stock. I used Redline's MT-90 GL4 manual trans lube in the transmission, and their 75W85 GL5 lightweight gear oil in the diff.

Sidenote: At 2000 miles the magnet on the rear diff drain plug was already kind of grungy... I'm not too concerned. That is pretty normal for rear gears while wearing in. The drain plug in the transmission was not bad at all.

Does anyone know if we can use a fumoto valve for the transmission drain bolt?

How does the transmission feel/shift with the Redline MT-90 GL4?