Rear differential for 2012 M37

[jrecufan]

Hey folks. Wondering if I could get some general feedback / thoughts. First and foremost, I'm not mechaniclly inclined so other than being familiar with generalities about a car, I have to take a mechanic's word.

My 2012 M37 just went out from under warranty (typical). So my rear differential started with a small leak. Took it to a local, reputable repair shop (no Infiniti dealer within about 1.5 hours) and they said the rear differential housing was cracked. They ordered a part and told me the part was $225 but labor was $700 because the way Inifiniti builds the M, you have to disassemble the whole differential (?) - can't just easily replacing the housing.

Took it in today for the repair and they told me they had gotten the wrong part in. And upon further review, Infiniti doesn't just sell the housing, you have to buy the entire cross member (this is their language). And, instead of $225 the part itself is $1280 (actually runs more than $1300 but they said they could give me a little bit of a break).

So now, instead of a $1000 fix, I have a $2000 fix on my hands. I know second opinions are good but this shop has a really strong local reputation and was recommended by a friend who has used them for years. My thing is I just can't believe something this expensive has happened out of the blue and with the car literally only 2-3 months out from under warranty.

I'm going to call the Infiniti dealer in Raleigh where I bought it, but does any of this sound like a problem the M37 or Inifiniti's in general have (maybe for this model year)? Is someone blowing smoke up my rear end about the housing / cross member?

General thoughts / ideas appreciated.

[wideopn11]

Really wish I had an answer for you...

How is it out of warranty at 2 years old? Even buying it used, you should still be covered.

https://owners.infinitiusa.com/content/ ... y_2012.pdf

Every new Infiniti comes with the peace of mind of Standard Infiniti Limited Warranties:
4-year/60,000-mile Basic coverage
5-year/50,000-mile Emission Control coverage
6-year/70,000-mile Powertrain coverage
7-year/unlimited-mileage Corrosion coverage
10-year/unlimited-mileage Seat Belt Warranty
4-year/60,000-mile Genuine Infiniti Accessories Basic coverage (when purchased at time of vehicle sale)
Up to 7-year/100,000-mile Infiniti Extended Protection Plan (optional)
2-year/24,000-mile Federal Emission Performance Warranty
4-year/60,000-mile Federal Emission Defect Warranty
8-year/80,000-mile Federal Emission Long Term Defect Warranty
4-year/60,000-mile California Emission Performance and Defect Warranties
7-year/70,000-mile California Emission Long Term Defect Warranty

[AlphaSnacks]

That is a powertrain failure. It's supposed to be warranty covered.

If, somehow, you are above mileage, you can get a rear diff separately and take it to any shop that knows how to work on cars like 370Zs, G37s, etc. The Ms are extremely similar to all of their smaller siblings. In fact, since you have an M37, your 7-speed AT has the exact same rear diff as that of a 370Z and G37. Definitely go to the Z and G forums and find out what shops they're going to get work like this done in NC. A diff swap is a fairly quick and simple job for competent tuner techs.

[jrecufan]

Wideopn - you were precisely right. I thought my warranty was 3 years. It's 4 for basic but most importantly the powertrain is 7. I didn't read your reply closely enough. I'm all set to get this taken care of under warranty.

Thanks for the response from you and Alpha. I actually responded that night but the site was having issues and it never went through as a post. Anywho - thanks again!

[wideopn11]

Great, let us know how it turns out.

[AlphaSnacks]

Great to hear.

[seldomseen]

Took it to a local, reputable repair shop (no Infiniti dealer within about 1.5 hours) and they said the rear differential housing was cracked.

While you're still under warranty it behooves you to have your car serviced by Infiniti despite the 1.5hr drive. You will quickly learn that just because a mechanic is certified/experienced. Not all mechanics will be mechanically knowledgeable about Infiniti cars.

[Panzer Leader]

I find it interesting that the Dealer you took it to, did not realize it was still under warranty...... They had the VIN, the year, and obviously your odometer reading..... I wonder if they were going to double dip.... Hit you, and then file with Infiniti for reimbursement as well.

[SwissCheeseHead]

I find it interesting that the Dealer you took it to, did not realize it was still under warranty...... They had the VIN, the year, and obviously your odometer reading..... I wonder if they were going to double dip.... Hit you, and then file with Infiniti for reimbursement as well.

OP took the car to a local indie first, thinking his warranty was expired, but then realized that it wasn't, so then drove it to a dealership for repair.

I've never heard of a rear diff cracking unless it made impact with something like a stone or something else in the road. Either way, it's good that you're getting if fixed under warranty. Let us know the outcome.