DIY: G37 Automatic Transmission Fluid Change, Pan Drop/Clean
The torque convertor is a huge reserve of fluid in these systems. When the engine is not running, some of the ATF fluid will drain back from the torque convertor to the pan, and thus why you see 1.5 litres of "extra" fluid draining from your drain point.... So, the engine must be running, and ATF pumping around the full transmission + torque convertor for you to monitor the correct level in the transmission sump.
I just made my DIY video. I know that there are tons of videos and information here, but if anyone wants to look at as many videos as possible to make the process easier, here is the youtube link.
I just made my DIY video. I know that there are tons of videos and information here, but if anyone wants to look at as many videos as possible to make the process easier, here is the youtube link.
YouTube Video
YouTube Video
Thanks, you're 100% right on level thing, I'm sure I'll get a lot of disagreements. I consulted with a 40 year experience mechanic locally and he also told me that the way I "leveled" my car will be good enough. Also, with the "level" I done, ATF will be slightly over and not slightly under, better over than under. But I am ready to embrace disagreements 

Good afternoon. I have been obtaining great information on this site since '08 after the better half bought her 2008 g37s (currently 159,000 mi.) It has been a great car without any major problems.
Usually, a short 3 mi. round trip for her job and approx. 6 500 mi. trips/year. Oil has been changed at 3k intervals w/Mobil 1 and various filters (Bosch, M1, and Wix).
Local Infiniti dealer has performed most of the recommended services (the important ones) on the car.
At 60k mi, I asked them to replace all fluids. I didn't look over the service sheet when she brought it home and assumed coolant, diff, oil, ps, pb, and trans fluids had been replaced. Very disappointed to recently find out they only did the coolant, oil, and ps, as per service history lookup.
So, trans, diff, and pb are original.
I wanted to do what I thought would be a 2nd drain and fill and I'm worried that it might be an issue with the trans.
I am asking for opinions on a slightly different method to drain and refill the trans that I haven't seen mentioned on here yet.
In the interest of mitigating the "shock" to the trans by replacing all of the fluid at once, I wondered if this would work:
-Drop/clean the pan and magnets
-Replace all but one qt of the old fluid
-Add 1 qt of new fluid
-Drain another quart @500 mi
-Repeat 3 times @ 500 mi intervals
-Do another pan drop and clean
-Fill with new fluid
-Pray?
I'm aware that some here are not proponents of changing the trans fluid (as per Infiniti) and I understand why they would support that philosophy.
However I can't help but think slowly introduced new fluid would benefit the trans. to some extent.
Which type/brand would you suggest (Nissan, M1, Maxlife,..).
We would like to keep the car until it becomes too costly to repair. It's a fun car to drive and the motor still runs like it's new.
I could be asking for information, that for the most part, has already been discussed here.
The veeerry slow introduction method of new fluid is the main difference I guess. What do you think?
Thanks for your help.
Usually, a short 3 mi. round trip for her job and approx. 6 500 mi. trips/year. Oil has been changed at 3k intervals w/Mobil 1 and various filters (Bosch, M1, and Wix).
Local Infiniti dealer has performed most of the recommended services (the important ones) on the car.
At 60k mi, I asked them to replace all fluids. I didn't look over the service sheet when she brought it home and assumed coolant, diff, oil, ps, pb, and trans fluids had been replaced. Very disappointed to recently find out they only did the coolant, oil, and ps, as per service history lookup.
So, trans, diff, and pb are original.
I wanted to do what I thought would be a 2nd drain and fill and I'm worried that it might be an issue with the trans.
I am asking for opinions on a slightly different method to drain and refill the trans that I haven't seen mentioned on here yet.
In the interest of mitigating the "shock" to the trans by replacing all of the fluid at once, I wondered if this would work:
-Drop/clean the pan and magnets
-Replace all but one qt of the old fluid
-Add 1 qt of new fluid
-Drain another quart @500 mi
-Repeat 3 times @ 500 mi intervals
-Do another pan drop and clean
-Fill with new fluid
-Pray?
I'm aware that some here are not proponents of changing the trans fluid (as per Infiniti) and I understand why they would support that philosophy.
However I can't help but think slowly introduced new fluid would benefit the trans. to some extent.
Which type/brand would you suggest (Nissan, M1, Maxlife,..).
We would like to keep the car until it becomes too costly to repair. It's a fun car to drive and the motor still runs like it's new.
I could be asking for information, that for the most part, has already been discussed here.
The veeerry slow introduction method of new fluid is the main difference I guess. What do you think?
Thanks for your help.
You should have them change the brake fluid, or do it yourself every 2 years.
I am not a proponent of mixing even though this is generally the power steering fluid exchange process, you don't get it all flushed. If you are going to go to the trouble just change it all but first drop the pan and clean the magnets first. Can use Amsoil atf, Motul ATF-1A, Mobile 1 Synthetic ATF, Castrol Transmax J (JASO 1A), or Pennzoil plat LV multi vehicle full synthetic. I used Nissan to flush and then switched to Amsoil on the last. Being totally level is not a big problem, just get close.
Also get this unit:
https://a.co/d/1pCC569
I am not a proponent of mixing even though this is generally the power steering fluid exchange process, you don't get it all flushed. If you are going to go to the trouble just change it all but first drop the pan and clean the magnets first. Can use Amsoil atf, Motul ATF-1A, Mobile 1 Synthetic ATF, Castrol Transmax J (JASO 1A), or Pennzoil plat LV multi vehicle full synthetic. I used Nissan to flush and then switched to Amsoil on the last. Being totally level is not a big problem, just get close.
Also get this unit:
https://a.co/d/1pCC569
Agreed.
I plan to do all of the fluid changes that are possible with the exception of the trans. Have you heard of the 1 new quart every 500 mi or so method, to slowly ease the trans back to a clean condition?
- Drain trans fluid into a container
-Drop/clean the pan and magnets-
-Replace all but one qt of the old fluid
-Add 1 qt of new fluid
-Drain another quart @500 mi
-Repeat 3 times @ 500 mi intervals
-Do another pan drop and clean
-Fill with new fluid
-Pray?
If I'm not mistaken, isn't that fitting for the 09+ transmissions?
I believe the '08 5 speed AT had a dipstick?
I plan to do all of the fluid changes that are possible with the exception of the trans. Have you heard of the 1 new quart every 500 mi or so method, to slowly ease the trans back to a clean condition?
- Drain trans fluid into a container
-Drop/clean the pan and magnets-
-Replace all but one qt of the old fluid
-Add 1 qt of new fluid
-Drain another quart @500 mi
-Repeat 3 times @ 500 mi intervals
-Do another pan drop and clean
-Fill with new fluid
-Pray?
If I'm not mistaken, isn't that fitting for the 09+ transmissions?
I believe the '08 5 speed AT had a dipstick?
I have looked at that and I'm pretty well aware of the procedure for the fluid changes on the 08 37s. My main question was regarding the quantity of, and how soon to introduce, new fluid into a transmission that has not been serviced for 159,000 mi.
I've been servicing my vehicles (trucks and cars) since I can remember. So none of the regular maintenance is daunting.
What do you think of the slow method by which to replace the old fluid without harming an old transmission.
New fluid all at once, seems to be not a very good idea.
New fluid over a long period of time and miles might be more beneficial than not servicing the transmission at all.
Thoughts?
You have a dipstick.... what is the condition of the fluid? Is it bright, cherry red, or is black/ burnt. This is the key to the whole debate.
A 15-year-old car, with ≈160K miles, if the fluid is good, I would be more inclined to leave it alone assuming the car shifts normally. If the fluid is black/ burnt then I'd change it.
For reference, my last ATF flush/ fill was 10 years ago at 69,500 miles. I am currently at 116k and my fluid looks brand new. I know I probably should change it, but for this I prefer to leave well enough alone especially at the rate I drive these days... This is just my 10¢.
A 15-year-old car, with ≈160K miles, if the fluid is good, I would be more inclined to leave it alone assuming the car shifts normally. If the fluid is black/ burnt then I'd change it.
For reference, my last ATF flush/ fill was 10 years ago at 69,500 miles. I am currently at 116k and my fluid looks brand new. I know I probably should change it, but for this I prefer to leave well enough alone especially at the rate I drive these days... This is just my 10¢.
If new fluid is introduced a little bit at a time, as opposed to a complete fluid exchange, the idea is to mitigate high amounts of debris dislodged by the new fluid and therefore possibly causing an issue with the transmission.
It would be a gradual cleaning.



