Over the July 4th weekend, I decided to finally do the first of a 3X automatic transmission drain and fill on my 08 G Coupe at 66K. I plan to only drain at the drain plug three times over two weeks so no dropping the pan or evacuating fluid from the cooler line.

Before the first drain, I checked the fluid level on the dipstick (after the car reached normal operating temp) and it showed 3/4 on the hash mark. After letting the AT drain overnight, I carefully measured the recovered fluid and it measured 5 quarts. I filled the AT with exactly 5 quarts using the same measuring cup. In other words, no chance that I refilled with the incorrect amount of fluid. Now the fluid level on the dipstick is showing over the limit on the hashed area.

Any idea why the fluid level is showing higher after the first drain and fill? Any potential damage to the AT driving with a high level of fluid?

I am the first and only owner of my G and this was my first ATF fluid drain. I'm frankly just puzzled. Your ideas would be appreciated. Thanks.

UCLAg37

 

Did you bring the car back up to running temp after the refill? If not maybe fluid was in the torque converter when you first checked but isn't after the overnight drain & refill. Just a guess, auto transmissions are not my area of expertise.

 

Yes, I checked the fluid level several times after the temperature was at a operating level.

I noticed that even after 11 hours of draining fluid, there was a continuous drip. I don't know much about torque converters (TC) in the G but I was wondering if there was a weep hole in the TC where the fluid was draining from. My guess is that it may take time for some of the new fluid to be circulated back into the TC, which I understand is primarily a self contained unit in many vehicles. Wondering if we have any experts in this area on this forum.

Thanks.

UCLAg37

 

How was your car lifted

 

On race ramps.

UCLAg37

 

You need it to be level if you can

 

I know w/ the 7AT you have to have it level (and the engine running) to get the proper fill.

 

just wondering how much more above the hash marks on the dipstick are we talking about? the new trans fluid would expand differently than the old fluid in your trans. since the new fluid is clean and without any solid particles and also being more viscous you may just be seeing normal fluid expansion.

 

It's been frustrating getting a consistent reading. I warm up the car to operating temperature by driving it, take it to park, shift through all the gears and park again. While the car is still running I check the dipstick several times after cleaning off the dipstick. I got a reading of slightly below the hashmark so I added 8 ounces. Today after the same process, it reads about 1/3 hashmark space over the top of hashmark. This happened twice so I removed some fluid the first time. The ground is level.

Compared to all the other cars I've owned, this is the first time, I've had such difficulty obtaining a fluid level reading on the AT. Am I doing something wrong? The new fluid is Nissan Matic S and the old fluid is Matic J.

UCLAg37

 

i wouldn't worry about the level you see on the hash marks so diligently. its not like you overfilled the trans by 10qts. it sounds like its just the fluid expansion of the new fluid you put in. being 1/3 hashmark space over the top fill line on the dipstick is not going to affect the performance or depreciate the performance of the trans. i believe matic j is the semi synthetic atf and matic s is the full synthetic atf so the viscousity and expansion of the fluid due to temp will vary.

 

Thanks gents.

I will say however, that the G feels so much smoother and responsive after the fluid change. I should have done this many miles ago. After two drains, the second drain the fluid was almost like new. I'm going to do the third drain a month or two later. I'm considering doing a drain and fill (1 cycle) every 12-15K miles for long term maintenance. Considering, I can only drain 5qts, at $11/quart for the Nissan Matic S, it is a small investment to keep the AT happy.

UCLAg37

 

Not a bad plan, especially if the car is going to be a long term keeper, and maybe even a hand me down to a family member many years from now.
I would drop the pan and get that cleaned up along w/ the pan magnets in the next drain & fill, or if you do another one 10-12k later.