pawel2009

Recently purchased G37x (automatic) with 105k miles.. might have transmission issue I already had transfer case replaced which fixed some of the issues. Seems like previous single owner drove the car hard (and maybe used the "manual" sport mode constantly).

Here's what I hear/feel:

1. Grinding when slowing down/stopping - especially if I used more acceleration before having to stop at next intersection / stop sign...
2. Feels like engine is braking, instead of brakes...
3. Seems like gravity is holding car "down" in lower gears
4. Accelerates slowly from stop... just sluggish, unless I hit the pedal hard, but that drives RPM's high needlessly; I think it should accelerate with less effort from stop.
5. Cannot drive hard at all (and don't plan to, just testing car) - but when I test, lower gears lag a lot, and grinding noise when going through gears 1-3 when starting to drive hard, and grinding when slowing down and stopping.
6. Vibration under brake pedal when braking (no vibration from steering wheel)

The big issue is grinding (the imperfect shifting between lower gears isn't that bad for a car with this mileage, and if driven hard, it's bound to hiccup). But it shouldn't hiccup when I'm driving gently, and it does occasionally; but it shouldn't grind/kind of feel like it's being slowed needlessly.

* Two mechanics told me that brake system is fine, and not causing the issue, so thus I'm thinking transmission.

I had the transfer case replaced at Infiniti dealer, and the grinding issue got much better than before, plus, the problem with steering wheel being more difficult to turn went away, and the car also stopped making noise while turning left/right at low speeds. But it seems like transmission still not working fine, despite Infiniti mechanic saying everything is fine (I have no warranty, and I asked them to let me know if anything else needs fixing, and that I'd like to get it fixed, but they didn't bring this up).

Thanks for your feedback!