Q45 diff swap

[450Z]

Has anybody tried to do a direct diff swap from a 90-96 300ZX NA into a Q45?I can't help but think that someone has done this as there are some gearing advantages to doing so.I'm trying to see if the internal splines for the half shaft flanges are the same for both units.

[T45]

What's the difference in gear ratio's between the two diffs?

[db_autotek]

I believe the Q45 has a 3.87 rear ratio and the 300zx has a 4.10 ratio. This means your acceleration will be better but city driving and top end will suffer... and your gas milage will go down. But if you dont care, then yes they are compatable. A few people here have done it. I think the preffered method is to get open both diffs and remove the 300zx gears and install into your Q45 diff housing.

[cccpman]

pretty persuasive arguments that state you will not achieve a higher acceleration and it may actually slow down some of your times (due to shift points changing)

[db_autotek]

Yeah I wouldn't do it.. but it can be done. You're right, shift points would change, and hell for that matter you might need a custom programmed TCU to compensate for different final drives with each gear and shift points. Right now my shift point is about 60 mph at full throttle from stop with OEM transmission and rear. Uh, thats awesome for me. lol.

[Q45tech]

When you post number with decimal points important that you actually check facts and not post error numbers.

3.538 and 4.083

[db_autotek]

Sorry 'bout that. I was using my bad memory.