So which gearing would you remcomend swaping to ? And what other parts would be need other then the gearing ? Would I need a new pumpkin or ? Links to parts would be very helpful. Also another thing does anyone have personal experience with this ? Is it a mod worth doing ?

 

I'm irritating the gf right now on the phone so I can't dig up anything but there are a few threads here and the majority of the best ones are on 370z forum. I posed the question of the 7AT swap and got a lot of guidance from Coop. In his thread he believes that 3.69 is best for the 7AT and equivalent to 6MT going with 4.08 but even more aggressive.
All the parts I had to get were : 6MT pumpkin w/ vsld ( 400.00 ) , Whiteline bushings ( not necessary but I wanted them 90.00 ) and 2008 6MT driveshaft and 2008 5AT driveshaft. ( because I have a 2012 and the driveshaft doesn't unbolt in the middle. If yours bolts in the middle you just need the 6MT rear half and will probably need to buy a whole driveshaft. I paid under 300.00 for both ). I'm more likely than not going to get a PST carbon shaft around November. I spoke with Mark there last week and wasn't too reassured when he told me I needed to re - measure with the 6MT diff installed. Kinda defeats my purpose and I'm tempted to just give him the measurement of my hybrid shaft and go from there. Just stay tuned for the 17th unless someone beats me to it. Oh!! All my stuff I got on ebay and I worked out the install for 300.00 including my RHFC'S. I plan to toss in an extra hundred because I didn't mention the bushings. I'll do the carbon driveshaft on my own later.

 

I've done this to a different car. I had a 72 SS chevelle with a built motor. It turned a fast car into a beast. I went from the stock ratio 3.07 to 3.90's in a 12 bolt with posi. When ever I put my foot into it, you were slammed into the seat. Fastest most powerful car I ever built. Put the gears into the G and it will be well worth it. It's the BEST investment to make the car very quick. here's another thread to read...

https://www.myg37.com/forums/engine-...oh-my-god.html

If you buy the pumpkin in classifeds, you're ahead of the game. Good gears and good VLSD unit. You'll want new bushings for the pumpkin, and a driveshaft(s), yoke that will bolt up. This'll depend on what year your car is... here is another thread regarding yokes and fitment...

https://www.myg37.com/forums/engine-...-on-awd-g.html

good luck and have a blast. My VLSD and 3.692 gears are going on soon...

Doug

 

I'm wondering if the 08 g37 3.69 auto rear diff is a direct bolt in unit for the 7at. Anyone know if this would work?

 

Ya, was considering that pumpkin but I also have a 3.69 from an 08 g37 I'm looking at also. I think the 08 g37 3.69 is a direct swap, might be easier and a little less aggressive than the 3.9.

 

The 08 5AT is a direct swap. I got scared off when I found the thread where G37Sam pulled his and counted the teeth and it wasn't 3.69. I don't believe his car was U.S. spec but it still spec'd that it should've been 3.69 and it wasn't. Did'nt want to buy one and then be mad as hell later on so I opted for the sure bet. I can't wait for the 17th to get this thing done. The only thing I don't have on hand right this second is the diff fluid and I'll probably go Redline or Motul.

 

I just filled mine with the Mobil 1 75-90. Has the friction modifier added already for LSD's. Meets OEM & is available locally.

 

My USA based 2008 G37 had OEM VLSD, 3.69:1 gears and included the NECESSARY three gear flange and the nose pinion which is what the 7AT needs. I suggested this as a CHEAP alternative. 4.08's would be almost too much, and this ^^^ would be a real noticable gain.

Salvage yards all over the US have them sitting for around $350. I propose it's the most bang for your buck for $350 you will get. And.... you can always switch it back.

Coop

 

For reference, which cars had 3.69 as OEM? 370z auto and manual? G37 coupe and sedan sport?

Please educate us

Thank you!!

 

Thanks for showing up Coop!!

 

here's a link to some tech specs

Infiniti G37 coupe, sedan and convertible technical information

scroll down to locate the info...

 

The 08 g37 5at had the 3.69 rear on it before they switched to the 7 at in the 09 model year. Should be a direct swap for a 7at g.

 

^^^ Yes. I believe the '08 is the ONLY three flange auto diff, and the only year that the auto came with 3.69 gears with this combination. Before that, the G35's had the four bolt flange.



This is a photo lifted from an http://www.ebay.com/itm/08-Infiniti-G37-AT-RWD-Differential-Assembly-R17628-/290967399077?pt=Motors_Car_Truck_Parts_Accessories&hash=item43bf022aa5&vxp=mtr for the same. It's $400 delivered.

I paid almost $2000 for the same gear ratio change (from 3.69 to 4.08 is the same as 3.35 to 3.69) and a lot more work (driveshaft swaps, etc.) I'd have LOVED to do this as inexpensively.

Who's going to be first?

Coop

 

I'm on it Coop, I'm guessing that it's a tight race between myself and dgey1 . I don't know if his driveshaft came in yet but I have everything I need sitting and waiting. I'm just waiting on the 17th to roll around.

 

I have purchased 3.9 diff for my 7at,should be on the car by the end of the month.