Following my topic about differential applicability here, I finally bought a 2007 G35 S differential. I was not 100% sure it would fit but decided to try. Since I did make it fit, I wanted to share my findings .

Although it is really similar, it is not identical as told by some peoples here on the forum.

To make things clear, my G35 is a Canadian 2003 5AT model with the sport package so it cames with the 3.3FD and VLSD. The diff I bought is from a US 2007 G35S 5AT so it is a 3.7FD with VLSD.

The 2007 diff use a different drive pinion shaft and a different flange for the propeller shaft.

I did take a look in the service manuals for each years and noted the differences between shaft and flange. Different flanges and different pinion shaft lenght.
The 03 have short shaft and 4 bolts flange
The 07 have long shaft and 3 bolts flange



This picture shows real life difference between the two:
- the older diff on top (03), is now fitted with the 3 bolts flange from the 2007
- the newer diff on the bottom (07), is now fitted with the 4 bolts flange from the 2003
Note: sorry I did not take a picture before swapping the flanges



Here you can get a closer look at the 07 diff and see the longer drive pinion shaft


And here the 03 diff with shorter drive pinion shaft



So there is two things that you must change...

First:
While the flanges are removed, you must swap the disc shown in the pic (I call it a dust cover because I don't know the real name). You must swap the dust covers because they will not fit into the opposite differentials. One is like "male" (the 03) and the other one is like "female" (the 07). They will not fit because the pumpkins are molded a bit different in the front.



Second:
After taking measurement and made sure the flange would interchange, you must cut the shaft so it would fit with the 03 propeller shaft
Cut about 1 3/8"


So now you have a complete diff assembly from a 07 G35S ready to be installed under your car.




Everything else about the diff beeing the same, it will now fit under your car. ENJOY!

Now I can not wait for spring (because my car is stored during winter) to do a test drive to see how going from 3.3 FD to a 3.7 FD will improve the "go" in my car

Oh well, it gives me time to do all the other things like plenum spacer, z-tube etc.

 

Awesome info. Thanks

 

Nice. Glad someone did this. You need to get in the car and see how the driving is.

Did you have to completely remove the pinion...and if so, was it simply removing the pinion nut and pulling outward?

 

I'm glad too because a 3.7FD should really give my G35 more "punch" , unfortunately there is too much snow here for a test drive right now

I did not disassemble anything. I've simply cut the pinion shaft with an angle grinder and a zip disc. Actually the 03 flange and nut were installed during the cut to prevent any metal bits from going into the diff.

 

nice work!

 

Nice job! It's good to see more people using simple ingenuity to fit OEM parts on non-OEM models.

But HOLY CRAP rust. The roads must be like pretzels up there. How easy was it to remove the axle, driveshaft, and chassis bolts/nuts?

 

BTW, did you repaint the 3.7 pumpkin? I just picked up a 3.5 pumpkin today and it has the typical Midwest rust on it, especially the stubs. I was thinking about hitting it with some paint, take care not to hit certain areas.

 

LOL yeah rust... typical here in Quebec where they use lots of calcium/salt on the roads during winter.

Luckily, everything was easy to remove... axles, driveshaft and chassis bolts. In fact, the rest of the body is in pretty good shape.

If you look carrefully at the 2007 pumpkin, the paint is so thin that it's no wonder it could rust quite easily. In fact, the pumpkin I've bought had only 16 miles on it but it already showed signs of rust even if it cames from south of the border.

Yes I did repaint it. The first pictures are how I got it and the last pictures are after I've painted the pumpkin with some krylon spray paint. I did not took great care on masking anything... only the rear aluminum cover actually.

 

How much did you pay for the diff and from where? I have the 3.5 in my 5at and want to upgrade to the 3.7.

 

Dave did you ever try out that test with the smaller mazda wheels at the track?

 

+1^

 

I bought a 3.5FD diff from a member here and sold it shortly afterward bc it whined.

During the process I barely missed a 3.7FD for sale. Keep your eyes peeled in the market section. They pop up from time to time especially if someone upgrades the pumpkin and buys an aftermarket one.

Currently I'm on the hunt for a 3.3 VLSD diff for sale (that doesn't have gears that whine of course).... hopefully we both find what we want!

 

Well I think I was pretty lucky to find one with such low mileage (16 miles). I found it in local classifieds. The guy that sold it to me bought a second G35 to rebuild his own G35X after an accident. He also told me it took him 6 months to find that other 2007 G35S because they were rare even though he bought it in the US.

I paid 700$ for the complete pumpkin and I think it is a fair price because it is almost new

That same guy also have the complete 16 miles VQ35HR engine and auto tranny for sale. But since he is in Sherbrooke (40 miles north of Vermont border) I doubt it would be of any interest for any people here.

Like tiguy99 said, keep your eyes open in the forum or local ads or maybe over at my350z.com for a 2008+ from a Z.

 

Thanks for the info. I'll keep a look out for one.

 

2008+ Z's have the same diff? Same FD?

What is the reason for the long pinion shaft?