have an 08 g37 journey I've recently noticed as I was driving to work the car starts to shake/ vibrate the seats and steering wheel at 50 mph. And the out of nowhere yesterday I started loosing 5th gear and I have two codes pop up (p1757 and p0735) what can I do to fix this till I'm able to get a new transmission

 

P1757 - Front Brake Solenoid Circuit: The Transmission Control Module (TCM) has detected an electrical fault, short, or open circuit in the front brake (or band) solenoid, which regulates hydraulic pressure inside the transmission.
P0735 - Gear 5 Incorrect Ratio: The TCM has detected that the transmission is failing to achieve the correct gear ratio for 5th gear. This happens when the transmission either fails to physically shift into 5th gear or slips out of it.

Call Justin at Nexenzo in Los Angeles and see if these codes could be linked back to the TCM (PCB/Electronics inside the transmission, degrades from excessive heat over time) as it's the primary source of failures within the transmission as these cars.

He sells a couple thousand rebuilt TCMs annually, so he's pretty knowledgeable.