I know, I know. Why on earth would I want to do that? I have my reasons, new 135 mile commute with less pay (laid off last year) = want better mileage. I can get a really cheap 350Z pumpkin (3.35 LSD) from a friend and I can put it in myself so cost isn't really a factor.

I have a 2008 5AT. I've already put over sized tires on and as soon as I get a job closer to where I live I'm putting the original back in because I love the car, but this will have do for now.

I've been reading a lot about how people lose cruise when going from 3.3 to 3.5 and definitely 3.3 to 3.7; however, does it happen the other way? I've read conflicting accounts.

What other issues might I need to look into?

 

I will trade you for my 3.3 and I will do all the labor...if you are in Socal.

PM me if you are!

 

I'm near Atlanta, sorry.

 

The issue for losing cruise control shouldn't apply to you since you have a newer TCM. However, if the stub axles don't read the same way as the stock FD then you might have issues with speedometer like some that went with a 3.69 FD from a G37 6MT. I wouldn't anticipate any issues with that though

 

So to verify. I have read where a 350Z or G35 has trouble because the drive shaft/transmission sensor has to be within tolerance the axle shaft sensors. Since my car apparently has a different TCM it calculates cruise control differently?

If you're sure about that you just may be my favorite person of the week.

 

I have 3.3 ring & pinion gears (out of pumpkin) - will sell/ship if interested

 

I can tell you that you have a different TCM and VB. All the people that I have seen have issues were 2003-2004 aside from the previously mentioned G37 pumpkin swappers. I believe the stub axles on the G37 to be different from the G35 models and that is causing them speedometer issues.

Nothing is 100%, but If it were my car I wouldn't be scared to give it a shot. Also, the 3.3 FD are easy to come by but most wont come with VLSD which you should have stock if you have JOURNEY w/ premium.

This is a good option, but i believe the 3.3 that Mike has is designed for the OPEN diff and not the same size as the 3.69 you are currently running if you have VLSD. If you don't have VLSD then this is a good option - aside from install costs.

 

good point - you're right 3.3 won't fit the vlsd in first gen... not sure about 2nd gen, but I doubt it's any different.

I have original open diff as well (mid 20K miles) out of pumkin... since OP is more concerned about mileage and not so much performance, it could be an option... but at that point the stub axles will probably be an issue.

 

I appreciate the information and for the cost, your right, I might as well give it a shot.

I'm really looking for the entire pumpkin as I'm going to keep the original in hopes of getting a job closer to where I live so I can put it back in. Also, swapping the gears instead of the pumpkin is a bit more than I want to bite off. I've tried dealing with backlash and all that and it never works out right.

I have a base w/Nav so no VLSD.

 

since you have no vlsd, the 3.3 will fit... if you change your mind about gears only let me know - I'll sell cheaper than full pumpkin and cheaper than buying gears new... you can always reinstall the 3.692 later...

Just an option ~

FWIW, the reason I have them is I installed 3.692 and Quaife - I kept the OEM in case I ever part out the car... at this point, when it comes time to sell the car I'm sure it will go with all mods (doubtful it will sell parted out)...

 

You should also have no problems finding a used 3.3 pumpkin with VLSD in the ATL area from car-part.com if you're wanting to pick something up locally. That's how I bought mine. Shipping on a 80lb pumpkin could be pricey.

As for MPGs, you really should do a cost benefit analysis to see if it's really worth it. Assuming you get 24mpg now and the 3.3 gear gave you 26mpg and gas was $3 gallon, you're only looking at saving maybe $1 a day. I honestly don't think the 3.3 gear will net you 2mpg either. I went from a 3.3 to 3.5 and it didn't even make a 1mpg difference in highway cruising. Around town, there was no change at all.

 

I have a 3.3 vlsd diff in my G35 05 sedan with sports package. im buying a 3.5 vlsd in two days. So i will be selling my stock unit. Im in NC