Edit: tl/dr - looking for a transmission shop in NW Houston or Cypress that will do an aftermarket rebuild or salvage yard swap.

My beloved 2012 G37 automatic RWD has a bad transmission. 139k miles, P0500 and P0720. Won't shift beyond 3rd gear.

Took it to Yates Garage in Cypress on recommendation from a friend. Quote is $4200 for the speed sensor and valve body which is apparently a single unit and must come from Infiniti. If they get in and discover a rebuild is needed, then it escalates to $8k.

Called Circle D which was recommended by many FB people. Again, will only use Infiniti parts, rebuild would be $7-8k.

Any suggestions for a transmission shop in NW Houston or Cypress that is maybe a little shadier and will do an aftermarket rebuild... Or even swap a salvage yard trans?

The car is worth about 6500 last I checked. I can't sink 8k into it, as much as I love it. I was actually prepping to sell it to my son when this happened.

Cpe or Sdn? I would throw a used low mile jap import transmission in it. Should not be anymore than 2k total with install and transmission purchase together.

Coupe.

Do you have a shop to recommend?

If you were in College Station, I might would do it. I am not so familiar with Houston area shops, but you should have plenty of options

Update: sourced a used transmission with 65k from a 2012 G37. Found a guy in Tomball to install it.

I had never heard this, but a colleague at work told me that Japan incentivizes purchase of new cars by making registration fees super-high after vehicles hit a certain mileage. So you can find importers with engines and transmissions from relatively low mileage scrapped cars. Not very expensive.

The failed part is a TCM / valve body which is not a bad DIY job (it sits just inside the trans oil pan) but the part itself is $2k+ from Infiniti. Supposedly all aftermarket / reman versions of the part are garbage. So I opted for the straight swap. Fingers crossed.

Hopefully it works out for you. I still kick myself that I sold my beloved '03 G35 that was owned by a grandma, only had like 90k miles on it, engine looked perfect, no tears in the leather.... her son was a mechanic and replaced every piece of rubber in the car (I found this out while getting tires - her grandson worked at Discount). Loved that car.

I'm thinking about picking up a G37 as a third vehicle. I absolutely loved the highway driving in my Maxima but got rid of it in large part due to the CVT and risks associated with that (along with wanting/needing a pickup). Now, with a pickup and a small SUV (Rav4; wife's car) with limited power, neither are effective highway vehicles and I have no qualms in getting a model that's been discontinued as I'd probably drive it into the ground. Plus, I like the RWD and 30+ extra HP it has over the Max!

Anyway, are trans known problem areas of this model, or did your's just konk out?

91AggieLawyer said:

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I'm thinking about picking up a G37 as a third vehicle. I absolutely loved the highway driving in my Maxima but got rid of it in large part due to the CVT and risks associated with that (along with wanting/needing a pickup). Now, with a pickup and a small SUV (Rav4; wife's car) with limited power, neither are effective highway vehicles and I have no qualms in getting a model that's been discontinued as I'd probably drive it into the ground. Plus, I like the RWD and 30+ extra HP it has over the Max!

Anyway, are trans known problem areas of this model, or did your's just konk out?

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I endorse your opinion of the G37 - it's just a great, fun little car. The VQ engine is really nice.

The guys at the last transmission shop I took it to said the valve body / TCM fails at a high rate for all Nissan and Infiniti models. When you search for P0720 there are many links to reddit, YouTube, and owner message boards which says to me it's common.

Depending on how handy you are, swapping it out isn't bad. It's just the price of the part that gets you. Maybe bake that cost into what you're willing to pay for a decent used G37.

Or better yet, buy a damn manual. If I didn't have to swap cars with my wife on occasion (or if I'd just had the sense to ignore her) I would have done that.

I've considered the standard, but not only will she be driving it some, I HATE driving standards in traffic -- and I'd be doing that a fair amount to maybe a lot of the time. Not to mention potential problems with the clutch, though admittedly, that's probably a less expensive repair.

Got it back yesterday. Pleased to report that (fingers still crossed) it drives just like it used to. All-in it cost me just over $1500, a far cry from what the transmission shops were quoting.

... Also, I did not have to resort to scavenging a beat-up altima (with paper tags).

He'll yeah. Glad to hear.