DIY: Transmission Oil Change

Skyscraper

Not as much of a shifting feel improvement as I had hoped, did this for my 60k service (first service since owning the car). The fluid that came out still looked pretty clean and smelled good as well so I'm not sure it needed it that badly. Still, good to know exactly when it was done last.

dkmura

Tranny fluid is not exposed to any combustion and gets worn out through the constant meshing of gears. It will usually look clean and not have much of an odor, but it needs to be changed periodically.

Skyscraper

You are correct, I suppose it's just a habit of mine to smell oils and I mean that it looked clean as in an absence of synchro shavings, not a color change like with crank case oil.

kenchan

you sure about that?

JARblue

I didn't run the stock mt oil very long, and it was my wife's DD for the first year. But I admit I did not notice much of a shifting improvement when I made the switch over to Redline around 10K miles. My heavy TWM DE shift knob and short shifter were much more noticeable improvements

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Skyscraper

Being under warranty and not being able to do any mods is killing me!

JARblue

I don't want to derail a tech thread such as this much further, but don't let the warranty stop you. I have 100K mile aftermarket warranty, and I've got a few mods including a tune. Almost everything that's actually broken on my Z hasn't been covered by Nissan (CMC, rear diff bushing, idle issues). None of that stuff was related to mods, and multiple dealers never said a word about any of the mods except as a compliment. I DIY most everything that's gone wrong and even replaced my CSC as a preventative measure when my CMC failed. The dealer did a headliner replacement for me under warranty, but that's it. If you really think it will be a problem, then your compromise is to put the OEM stuff back on before you take it in for warranty service

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Skyscraper

Yeah, keeping the oem parts is a good call. I'm still new with the car, only had her for 5 months, so I'm gonna chip away at the mods after making sure I know what I want. Getting ready to have the CSC replaced since I'm getting clutch pedal stickiness, different engage point when cold and a rattling vibration in the pedal Luckily my warranty covers it, oddly enough, not the headliner. Definitely, gonna swap out my pedal assembly as well after that's done.

sizziano

Well diff fluid is the same but its usually nasty looking

dkmura

Diff lubricants are completely different. That sulfur odor comes from high-pressure additives needed there, but DON'T use diff lubricants in your gearbox, those same additives will damage the tranny and shorten its lifespan!

sizziano

Of course but I'm talking about the way it looks not smells.

dkmura

My point is, there have been Z owners who've refilled both their tranny and diff with the SAME lubricant. Your comment, "diff fluid is the same" could be misconstrued and I wanted to be accurate. Visually speaking, I've found Redline MT85 (my gearbox lube of choice) is quite a bit lighter, almost honey colored, than the darker hues of synthetic diff fluids from Valvoline or Motul.

sizziano

I see, makes sense.

Akurei

Are you able to reuse the drain and fill plug washers? I done other transmission fluid changes on other cars and they were fine reusing the washers and never leaked even though the manual says to replace them. However, i heard some manufacturers use crush washers on theirs. Is the 370z one of them?

N8GTOL

The washers on the transmission are not the same type of crush washers that are found on the oil pan so you might be able to reuse them without issue but why risk an oil leak and a new tranny for a couple bucks worth of washers