I have an 2005 Performance (6MT / VLSD) and thinking about future upgrades for the diff. I would like to build a spare pumpkin to allow me to collect all the parts over time and minimize install cost/downtime. The shopping list will include:

- Aftermarket LSD
- 4.08 gears
- Nismo diff cover
- Poly or solid bushings
- spare pumpkin

My main question is in regards to the pumpkin itself. Obviously I can seek out a pumpkin from an exact year/model as mine and build from there. But what about cross compatibility across years/6MT/5AT/ and Z/G? I know the different OEM FD gears in each, but I'm thinking that they don't matter since dumping those anyway.

Would a pumpkin from a 2003 G35 5AT (3.3 FD / non-VLSD) work for my build?

And I'm I missing anything else, besides shims etc? I will let a pro/shop hand the install. Any insight is appreciated.

 

If i remember right you need a 3.5 housing, they are different.

Contact Z1, they will know best and get you great prices on the parts.

 

3.3 auto diffs definetly different. Picking up a spare diff shouldn't cost more than $200 and relatively easy to find.

 

Thanks folks. I'll seek out a 3.5/MT Z diff to keep things simple.

 

Is there a way to identify the A/T differential since the pumpkin itself is different?

 

You can open up the cover and check the gear ratio stamped into the side of the ring gear, or you can mark the input shaft and the stub axle. If you rotate the input shaft 3.3 turns to get one rotation on the stub axles, it is an automatic. If it takes you 3.5 turns to get 1 complete rotation on the stub axle, then you have a manual. Not sure if you can tell if it is a base or VLSD without pulling the stub axles out, or cracking open the cover. Anyone else know differently?

 

CHANGE OF PLAN:

I acquired a pumpkin (VLSD w/4.08 gears), but no flanges/stub axles.



My rear diff bushing is blown, so I want to take the opportunity to upgrade. The plan is to:

1- drop/uninstall stock diff
2- removed stock diff flanges
3- install diff flanges on new/spare diff
4- remove stock bushings (3)
5- install new poly bushings (KDT911 kit)
6- install new/spare diff
7- fill spare diff with gear oil


I'm going to have a shop do the work, but I would like to make sure I understand what needs to be done. I'm concerned about removing and installing the flanges (stub axles?).

Do these slide out (and in - with force) without having to access the inside of the differential carrier/pumpkin? I have searched around and found one thread that suggests that this is the case (2 circle clips required?). So I guess I need confirmation and details. If it's true, I think I will also need a pair of side-oil seals and a breather (missing on spare diff).

2x [38342] DIFFERENTIAL SIDE OIL SEAL
1x [38225+A] CIRCLIP-SIDE GEAR
1x [38225] CIRCLIP-SIDE GEAR
1x [38351G] BREATHER


Any help/input appreciated. thanks.

 

Side flanges i just tap out with a mallet. Same with putting them back in.

 

I just swapped in a 2008 G37 vlsd into my 2003 350Z. Added bonus is the G37 diff has a 3.7 gear. A little extra ummmpphhh!