just curious which final drive gears work with the 03 5at and what cars I can source them from. I am trying to get 3.5 gears and was wondering if I can get them from the 6mt g35 as well as 350z?

 

im interested to know as well!

 

Yes you can get them from the 6MT. But I would recommend 3.7's for the 5AT since they have weak gearing to begin with.

I wouldn't be able to justify the price of labor + the parts for just a very mild increase from 3.3 to 3.5
.

 

Just remember that MPG is a direct relationship with engine rpm, so a 10% increase in rpm will reduce MPG by a little less than same amount.

Whether 5% [3.5] or 10% [3.7] more fuel consumption is worth the change.

Don't be fooled by current ~~$2/gallon it will go higher as economy recovers and Federal/State Fuel Taxes are increased by democrats to pay for bailouts.

An extra $1 per gallon could pay for bail outs [$700 Billion] in 15 years.

 

I have 3.5 on my 03 AT. They are the gears for a 6mt. I put in a Quaife diff at the same time. You cannot use the 6 MT gears without changing the diff - they will be too small. The AT FD gear is thicker.

 

Slider, how much did all of that cost out the door?

 

Check around here see if you find what your looking for

http://www.z1auto.com/prodmore.asp?m...ne&prodid=1726

 

$1,295 for the Quaife, $400 for the 3.5 gears and about $300 for the install ~ $2K total. It's a different car after...

 

Slider, thanks in advance for the info. How long was the install process?

Do you guys think I'll need to upgrade my LSD as well? I'm new to this mod and aren't sure whether or not I need to swap out the LSD especially since I have a 5AT G35

That's good to know as well. What kind of MPGs are folks with upgraded FD gears seeing now?

 

Damn--- $2k. HOW MUCH DIFFERENT?

 

Seriously! I want to know too. If we can get away with the pumpkin itself, I think that would make the process MUCH easier. The jury's still out on whether or not I need the LSD or not. Do any experts want to chime in?

 

Hey Tiguy, I didn't have LSD, that's why I switched. The 03 5 AT Sedan, had an open diff. A real bi*ch in the snow - if one wheel started to spin, VDC stopped it, then the other would spin, VDC stopped it... until the gas pedal was on the floor, but RPM was 750. VDC off wasn't much better - the spinning wheel just spins faster.

Going FI is like driving in the snow all the time. The Quaife is better than LSD because there is no slip. The diff is gear driven - no limited slip and guaranteed for 25 years even if using on the track. Now, the only way to spin a wheel is for both of them to spin and I'm OK with that (through 1st, 2nd and half way through 3rd - if I want to). Most of the time VDC does not interfere if both wheels are spinning.

I hope this explains "how much different". If you wanted to drift a car, this would be the best way to go, but for traction and transfer of power to the ground, it can't be beat (without AWD).

 

going shorter than 3.692 (3.7) in an AT might not be advantageous since we only have 5 speed transmission (a 6 or 7 speed would be great for 3.9, 4.0, 4.1)...

3.5 from an MT is a direct swap of entire pumpkin and an economical choice for many – sometimes MT will sell or swap if they are FI and want 3.3...

3.7 will require LSD (the ring gear is thicker on AT 3.3 with open diff, so any shorter (3.5, 3.7) final drive will not fit.

If you ever intend to add a LSD, doing it when you install ring & pinion would be the logical thing (so you don’t pay twice)... 3.7 and Quaife is a great combo, I love mine… fun factor comes mostly form the FD – but the ATB Diff is good during hard cornering… there are cheaper LSD alternatives though.

 

I might be gettin a 3.5 pumpkin with lsd from a 6mt. I have a 04 AT Sedan with an open diff. I was thinking of going with 3.7, but i think that will be too aggressive for normal freeway driving, and it will be much more expensive. I found a person selling their 6mt pumpkin for 300 with lsd. another 300 for install. I am putting new seals in there as well. Oh and when u swap the pumpkin, you can also change the diff fluid at the same time. Im gona get amsoil put in there.

 

3.5 VLSD pumpkins normally go for $350-$450 shipped. I got mine for $375 shipped on here and did the install myself. It takes no more than 2 hours to do a driveway install, 4-6 hours if you've never done it before.