2003 G35 5at reverse slipping
 

Hi there, this is my first post since owning my car. This forum has been an invaluable research tool. My car just hit 100k ( I bought it with 85k).I figured the transmission was due for its 30k dump and fill. It came out pretty black, but not burnt smelling. Refilled and now reverse slips. You can "blip" it and it builds enough line pressure and will chirp the tires and grab. But if you slowly give it gas it shutters and slips. Forward, manual mode etc all work great. Thoughts? Valve body issue? Filter? Blown reverse clutches? Programming?
I already sourced a local low mile transmission, but before I go through the hassle of swapping I thought I'd get your guys input. Thanks again

Filter is just a large screen filter so I doubt that's the problem, you're probably just low on fluid. Get it up to temp, run it through all the gears, park, check fluid.

You did use Matic-J or Matic- S fluid yes? ACTUALLY NISSAN FLUID, not just a compatible fluid?

I'll check the level again. I used the valvoline matic compatible fluid.

The big reason it's not recommended to use anything other then Genuine Nissan Matic - S/J is because the friction modifiers are not the same with "compatible" fluids and you end up with problems exactly like you're experiencing. Since the fluid was pretty black anyways and the drain/fill only replace about 1/3 of the total volume I would plan on another drain/fill soon and use actual Nissan fluid the next time.

I still bet you're just a little low on fluid though.

Okay, I'll give that a shot. Thanks!