I'm only posting this here because it is 07+ related info that I wanted to share with another forum member. I figured others might be interested as well. I'm comaring our stock rear end with that of the 370Z since most aftermarket products are marketed towards the Z. Knowing what similarities we share with the Z means we know what LSD's, FD's, driveshafts, etc fit and what doesn't.

This is information I've gathered from the "Driveline" section in the FSM regarding the stock LSD and open diff in both 5AT and 6MT G35's. This info is for the RWD models ONLY. This info may be the same for the G37 sedan but I'm not sure. This is research based upon what I've collected from the FSM therefore it is solely based on that specific source and not real world experience or testing.

First of all, ALL G35's (RWD only) whether base, journey, sport, LSD, open diff come with a 3.692 final drive ratio. Unlike the 370Z which differs depending upon the transmission (3.692 for 6MT and 3.357 for 7AT).

The only difference between the LSD equipped models and non-LSD models for the G35 is the LSD itself. No other notable changes are made to the rear end. Meaning you should be able to swap a factory LSD on a non-LSD car without any other changes or modifications.

Since all RWD G35's come with the same FD ratio as the 6MT 370Z, any aftermarket LSD should theoretically fit without any other modifications (assuming the LSD is a direct fit into the 6MT 370Z).

The specifications below are for the RWD G35 with factory LSD




The specifications below are for the RWD G35 without factory LSD



Note that the LSD-equipped differential is called R200V while the open differential is R200.


The exploded views below compare the 5AT and 6MT G35's both equipped with factory LSD's. Note that the only apparent difference is the driveshaft flange circled in red.







That is it for now. I will update this thread with info regarding the 370Z and hopefully G37 sedan.

 

Thanks for the info. I wish I could do the final drive mod, but I have an 5AT and AWD...

 

In the general specs sections above what is meaning of "number of pinion gears" : 4 for LSD and 2 for non LSD?

Thanks.

 

Those are the small gears (also called spider gears) that are inside the diff/lsd itself.

2 pinion gears look like this (you only count the gears that have a shaft running through. The 2 other gears are not pinion gears)>>



This diff has 4 pinion gears>>



The addition of 2 more pinion gears is to increase durability of the LSD by allowing 4 gears rather than 2 to spin between the 2 main gears (the ones we are not counting)

 

ah! OK thanks for the expl. I thought those (2 and 4 gears) were referred to as "planetary" gears. I guess they are called "pinion" gears.

Anyway, my interest in in G35 6MT differentials is because I would like to make my final drive taller. Instead of 3.692 I would like something like 3.077. The reason is 1st gear is so short, it is not very useful (unless you are at the drag strip) and hard to engage smoothly because it is so short. I often launch in 2nd ( I have clutch pedal modified so I can feel clutch engagement point better, smoothly launching in 2nd is difficult with stock clutch pedal configuration). If I could re-gear to 3.077, 1st would be taller, making it more usable and in 6th, at 75-76mph, I would be at 2500rpm instead of 3000, like in G37 with 7spd auto. Of course all 6 gears would be taller but that would be fine for my daily driving usage, actually it would be an improvement not to mention improved fuel economy. In my opinion, it is not possible to get good fuel economy with a 3.5l v6 spinning at 3 grand while only going 75mph! When I step on the gas in this condition and the car takes off, no real need to down shift so that tells me I am burning excessive fuel producing power I am not even using while cruising on fwy at 75.

We used to have a Saab 93 6MT with a 2l turbo. When in 6th at 3000rpm, it was at 92mph. That car got 30mpg fwy too without even really trying too hard.

BTW, I have had no luck finding different differential gears for 2008 G35 6MT. There do not appear to be any gear options out there like there are for American cars and trucks. Does anyone know of any? I checked Jim Wolf Technologies and the website has no info on any diff options. Nice twin turbo option though! ... for 7 grand!

 

http://www.z1auto.com/prodmore.asp?m...ne&prodid=3234

There's a 3.3 FD listed for the Z33 and V35, you should contact them and see if it fits the V36/Z34 diffs. They know a lot about the G/Z.

Here's their full driveline parts

http://www.z1auto.com/submodel.asp?m...&cat=driveline

 

Thank you Q8y. I learned something from your post.
This should give people idea of going fast not only depends on massive power.

 

Q8y,

Thanks for this link and info. This is more info than I have been able to find so far. I spoke with them and they stated differential is different for my car 2008 G35 6MT sedan) so I would also have to change whole differential assy. Then I would have to add limited slip, which I already have in my car. So... I will think about this. I guess if I find a clean used 3.3 diff, then have Z1 install some aftermarket limited slip setup, I could partially get what I want. Seems like a lot of trouble to go from 3.692 to 3.3. On the plus side, my stock diff would remain intact and could be reinstalled if I needed to switch back. I wanted to go to more of a 3.1 ratio but I don't think that is an option.

 

If you changed your gears the the 3.3, your car would become very slow.

 

I'm not sure if you really have to change the entire diff case. That may be true for the previous models since the 5AT and 6MT models had different setups but for the V36, they are identical with the exception of the drive shaft flange (circled in red in the original post). But then again I'm only assuming based on what I've read and seen. You can get a clean diff case from the junk yard and try it out I guess

 

Q8y,
That was the direction I was given by guys at Z1Auto. I will look it up when I have time, check part numbers and service manuals etc... see what I can find. If I come up with anything conclusive I will post it on this thread. I just happened to be under a G37 IPL today and looked at diff installation. It doesn't look like it would be too difficult to swap out. looking at it and doing it are two different things though!

07-G35-MT/S
We are talking a gearing change of about 11%. I doubt car will be slow. I pretty much just drive around in it normally. What it will mean to me is it will space the gearing out some so I am not always having to shift so often and make it more relaxing to drive. I have had other cars with 6mt, and none were geared as short as G35. This is one of the first things I noticed about the car when I got it. Good for quick 1/4mile times i suppose.

If I want to go fast, I just ride my motorbike

 

good to know. thanks for the information Q8y. a buddy of mine and i are going to attempt swapping rear differentials today. his being an 08Z (HR) and my G37 sedan. Both 6mt. alittle concerned about fitment. From what I've read, it seems that it'll be a direct swap, but more of less, I'm concerned about some sort of ABS sensors that go into the rear differentials. We'll find out...

 

Including axles but not including suspension components correct?

 

You're going to need to either purchase a wooden shipping box or, and this would be preferred to save money, make your own. Just be sure to use 4x4 brackets under it so it can be forked or pallet jacked up into the shipping truck (EDIT: Standard pallet jack is 27" wide so make sure to give at LEAST that much room, ideally you would just have 4x4 on the outer edges and two in the middle that are about 8-10" apart). 2x4 for the frame of it (add a couple cross pieces on the top so it can be walked on, and wrap it in OSB but leave a few inspection window slits otherwise they're going to be prying your container apart somewhere during delivery.

Probably going to need 8' 4x4, 32' 2x4 just use cheap douglas fir for that. 1 sheet of 7/16 OSB and a box of screws. Total cost to make the box will be like $30. Secure the assembly to the bottom of the shipping skid with a cheap pack of ratcheting tie downs, you can get those cheapo 500# orange ones for like $10, if you have access to a banding tool then just use that instead. Might be able to get away with some lag bolts down through the subframe bolt holes (with big washers) but the differential would still be detached so I would just strap it down to the bottom of the shipping container with cheap ratchet straps.

As for the weight, get a couple bathroom scales and set the subframe across them (use wood to protect the scales). The shipping company will need an EXACT weight, you will need to drain the diff as well to avoid the hazardous delivery surcharge a lot of them will tack on for stuff like that. Call around to local outfits (you can call your local port to get a list of recommended LTL shippers, they're usually friendly enough to tell you who they would recommend). Then just arrange the skid so they can forklift it off the bed of your truck and you will save shipping cost by driving it to your shipping port rather than them sending out a residential delivery truck with a lift gate and a pallet jack.

Shipping cost will probably be around $150, that's about what I spent last time I shipped a 300# assembly It's going to be a class 85 package because of the odd shape / weight / and being auto components on a pallet. Same as shipping a transmission, axle, engine. You can verify that once it's all crated up and weighed though.