I have a 2006 G35X. For some reason, it does not seem to shift into OD. RPM's are around 2600 at 40 mph. Any suggestions?

Try throwing the gear selector into manual mode to see what gear shows up on the dash. Or try manually shifting from 0mph and count the gears to ensure when you select for 5th (Drive) it really is shifting.

There's a possibility it's not going from 4th to 5th, but that should happen above 40mph anyway.

Should I have the trany fluid changed? It has 98K. It shifts from Gears 1-3 just fine. Depending on how much pedal, usually conservative, it will shift into 4th. But you can hear and feel that its not going into OD.

Robert L.

I'm always a proponent of fresh fluid changes. If you don't mind spending a bit more, let a shop do a full flush and filter. At 100k, it's due. Keep us posted!

Thank you! Should I not pay attention to what some mechanics say about changing transmission fluid and filter...that it may actually cause problems?

If your trans is in bad enough condition at 96k that a trans fluid change would send it over the edge, it'll happen soon anyway.

Clean fluid is ALWAYS better. Period.

thank you. One other thing, I will be replacing a Bank 2 catalytic converter soon. Is there any way with this code, it could possibly affect the status of the shifting problem? Also, I did what you said. After about 45 mph I put into DS mode and it showed that the car was still in 4th gear. I placed into 5th and the RPM's dropped a little. Does that mean it is not shifting into OD as it normally would?

That sounds like it is not shifting as designed, yes.

The cat would not have any effect on shifting to my knowledge.