pfregeolle

iTrader: (15)

Can someone real quick just confirm whether the actual iron diff carrier between the MT and AT 350Z are the same or different?

I bought a used AT carrier so that I could plop a Tomei diff into it (assuming that it was the same dimensions in every way), and I'm kind of worried that the actual housing is different than a MT housing which the Tomei is made for. . . .

I don't know, it looks like from these diagrams between the open diff and the VLSD, that the cases are identical:

http://www.nissanpartsdeal.com/parts/nissan-final-drive

dboyzalter

iTrader: (3)

Im pretty sure they all have the same housing, just different stub axles and gears... Between base auto 6 speed etc... Could put the tomei in your rear end and keep the auto with its sweet gearing as your spare.

Did you get base model stub axles? Or is your doner from a base auto? The rear axle info is a bit scattered around.

Could call nissan and see if the part number is the same.

pfregeolle

iTrader: (15)

I bought all new OEM Nissan parts for a stock VLSD, which is what the Tomei diff is made to fit.

I have a 2006 MT Base that came with the open diff.

I bought a 2005 AT Differential that came with an open diff and the stubs and all the guts. Cracked open this diff and removed everything. Replaced all pinion bearings, seals, and installed a 3.9 FD pinion gear. Installed 3.9 FD Ring gear on the Tomei and used all new OEM Nissan bolts. Jammed the new diff into the AT housing with brand new side bearings, assuming that the diff housings are identical between base/enthusiast/touring/grand touring/track and MT/AT. Popped in OEM Nissan half shafts that are made to fit the OEM VLSD, as that's what the Tomei was made for.

The Open Diffs have identical half shafts side to side; the VLSD has a longer half shaft on one side. The half shafts I bought are not identical, because they should be for the VLSD.

Also to clarify, the Tomei diff I have is the HA model which is made for the VLSD; not the HXA model which is made for the open diff.

Yes, all my pinion and ring gear contact patch, backlash, preload is good.

Something just seems fishy and I'm now starting to wonder if the actual diff housings are slightly different. I don't think they are at all, but it could be possible I suppose.

dboyzalter

iTrader: (3)

It could be possible... According to their description its not for the automatic... But I dont know why Nissan would go through the hassle of changing the housing on the same model cars... Wish I knew 100% for you. But if you have it all opened up your ahead of me.
https://www.z1motorsports.com/transm...sd-p-2813.html

I got a base 6 speed differential as my spare but haven't done anything with either of them yet.

The want is high for the 3.9

pfregeolle

iTrader: (15)

To be honest, I might suggest going 4.08 depending on what you want to do with the car (like if you're interested in drifting).

guitman32

iTrader: (15)

What about it seems fishy to you? If you installed everything and are getting a good pattern what is the problem? Just the half shaft situation?

pfregeolle

iTrader: (15)

I'll try and get a photo by the end of the week; the driver's side stub doesn't seem to want to pop all the way in. The stubs have some what of a cup and lip, where the cup seats itself into the carrier and the lip rests around the edge of the hole the shaft goes into. It's definitely in there, because I can feel the circlip snapped into place. But the shafts still have some slight visible movement.

I broke the diff in with figure 8's and slow driving. Once I got up to speed a little bit, I felt a bit of vibration. Changed the oil, seemed to go away a little bit; vibration comes and goes now depending on speed. I may just change the fluid again since it seems like everything is still breaking in.

guitman32

iTrader: (15)

I have only rebuilt carriers from mt 350s and 370s, never rebuilt an auto housing specifically so cant comment there. But i will say some movement of the shaft is completely normal.

pfregeolle

iTrader: (15)

That makes me feel a little better about it then. I think I'm just not used to the harshness of the Tomei and new gears, let alone all those new metal moving parts still breaking in.

dboyzalter

iTrader: (3)

Its basically just for the fun of it. I was thinking 4.08 but its a semi daily driver when the weather is nice and the go too car for day trips etc... Maybe I should just leave well enough alone and just spend the money on some light weight wheels and some tires.

guitman32

iTrader: (15)

A steel plate clutch type diff is definitely an eye opener..