Hey guys, I have noticed that after changing my trans fluid, used Nissan fluid, several times to flush out all of the old fluid my car will shift rough and the clutch sometimes slips. It is only when the fluid gets warm. Right now it's 20 degrees out and when I drive it after it has been sitting it shifts great. It's once the trans warms up that it starts to shift rough and slip. When I changed the fluid I always put in the same amount that I drained out. With the symptoms, I am thinking that once the fluid gets warm it expands and then there is too much fluid in the trans and that it was is causing my issues. Any help would be great. Thanks

 

Specifically, which Nissan fluid did you use?

Also, how many miles on the tranny and how frequently was its fluid serviced during its life prior to this?

 

I used Nissan Matic-S. The trans has 85k miles on it and I am not sure how many times it was serviced. I've had it for the past 20k miles and have drained and refilled 3 times to get rid of most of the old fluid.

 

Was the old fluid particularly dirty, cooked, have metal residue, and/or generally nasty looking? Or was it fairly normal with a distinct pinkish/red tint?

When a tranny is shifting ok before you change the fluid, but then awful afterwards, there is the possibility that the tranny was severely worn and the fluid was full of that worn away material. Essentially, it can act as a traction aid, and then when it is replaced with new clean fluid, that traction is lost and the tranny starts slipping.

If the tranny was not worn, and the fluid was in reasonable shape, the more likely conclusion is along the lines of what you've mentioned: that the fluid level is wrong and is causing the problem. Here's a copy of the FSM transmission section: http://www.nicoclub.com/FSM/G35/Seda...5_Sedan/tm.pdf
Fluid info starts around page TM-217
Troubleshooting starts around TM-77 and then then there is another section around TM-191

 

From what I remember it was fairly normal looking. Nothing that caught my attention. I'm having an alignment and coolant drain/refill done tomorrow at the dealer so I'll ask them to check the ATF level. It 's just way too cold here right now to go out and check it. Thanks for your help.

 

The dealer can readily tell exactly where the correct level is because they can get the exact temperature of the fluid through the diagnostic system and then look it up on a chart. The volume changes significantly with temperature, so knowing exactly what temp it is makes it fairly easy to get the proper level.

Please report back with the outcome.

 

They said that the level was fine and that the fluid wasn't a weird color or anything. Who knows what the problem is.

 

I meant the fluid you already flushed out, not the current fluid.

 

I meant to say that that was what the dealer told me about the fluid.

 

Did the dealer see the old fluid you flushed out?

 

No, I did it a while ago. The old fluid is long gone.

 

G 35X 2007 sedan needs nissan matic-J fluid

 

Partially right^^

Matic S replaced Matic J and they are both approved AT fluids for the first and second gen G's.