DIY: Transmission Oil Change

JARblue · 10-20-2014, 10:23 AM

Quote:

Originally Posted by dkmura

Most likely explanation is your car is not perfectly level. Whether it's how you jacked it up and supported it on four jackstands, or the floor or driveway you're using slants sideways slightly, it can throw the fill line off. In any case, you don't want to overfill your tranny, so three quarts should be plenty.

I jack my car up perfectly level (within 0.01% slope, checked with a properly calibrated 4' digital level - I have to use different size jack stands to get it perfect in my garage) and refilling the transmission with exactly 3 quarts of fluid never causes overflow. You can't overfill it because the fluid will just pour out the fill plug when it's full. IMO it is better to pump enough fluid in there to make it overflow than to leave it short. However, if you can feel the fluid level when you stick your finger in the fill hole, it should be fine even if you only used 3 quarts.

onzedge · 10-20-2014, 10:26 AM

Quote:

Originally Posted by JARblue

I jack my car up perfectly level (within 0.01% slope, checked with a properly calibrated 4' digital level - I have to use different size jack stands to get it perfect in my garage) and refilling the transmission with exactly 3 quarts of fluid never causes overflow. You can't overfill it because the fluid will just pour out the fill plug when it's full. IMO it is better to pump enough fluid in there to make it overflow than to leave it short. However, if you can feel the fluid level when you stick your finger in the fill hole, it should be fine even if you only used 3 quarts.

Skyscraper · 10-20-2014, 06:31 PM

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.

JARblue · 10-20-2014, 07:31 PM

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

Skyscraper · 10-20-2014, 07:34 PM

Quote:

Originally Posted by 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

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

JARblue · 10-20-2014, 07:46 PM

Quote:

Originally Posted by Skyscraper

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

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

Skyscraper · 10-20-2014, 10:19 PM

Quote:

Originally Posted by 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

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.

dkmura · 10-21-2014, 09:00 AM

Quote:

Originally Posted by 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.

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 · 10-21-2014, 10:53 AM

Quote:

Originally Posted by 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.

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 · 10-21-2014, 11:26 AM

Quote:

Originally Posted by 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.

you sure about that?

sizziano · 10-21-2014, 01:28 PM

Well diff fluid is the same but its usually nasty looking

dkmura · 10-22-2014, 10:43 AM

Quote:

Originally Posted by sizziano

Well diff fluid is the same but its usually nasty looking

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 · 10-22-2014, 02:03 PM

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

dkmura · 10-23-2014, 10:34 AM

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 · 10-23-2014, 01:49 PM

Quote:

Originally Posted by 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.

I see, makes sense.

10-20-2014, 07:31 PM	#169 (permalink)
JARblue A True Z Fanatic Join Date: Mar 2011 Location: Austin, TX Age: 43 Posts: 36,450 Drives: 11 Z34, 98 E36 M3 Rep Power: 2684440	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 __________________ 2011 370Z 6MT Sport Gun Metallic \| ARC \| CJM \| Ecutek \| FI \| Fujimura \| R2C \| SPL \| Stillen \| TWM \| Z1 \| ZSpeed \|

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10-20-2014, 06:31 PM	#168 (permalink)
Skyscraper Base Member Join Date: Jun 2014 Location: The skies above NorCal Posts: 72 Drives: 09 Touring Sport 6mt Rep Power: 11	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.

10-21-2014, 01:28 PM	#176 (permalink)
sizziano Base Member Join Date: Sep 2014 Location: CAE, SC Posts: 68 Drives: '18 Sport TECH Rep Power: 11	Well diff fluid is the same but its usually nasty looking

10-22-2014, 02:03 PM	#178 (permalink)
sizziano Base Member Join Date: Sep 2014 Location: CAE, SC Posts: 68 Drives: '18 Sport TECH Rep Power: 11	Of course but I'm talking about the way it looks not smells.

10-23-2014, 10:34 AM	#179 (permalink)
dkmura Base Member Join Date: Feb 2009 Location: Aurora, CO Posts: 108 Drives: SCCA T1/3 and GT3 Z Rep Power: 16	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.