Needing some help. I have the 3.69 vsld pumpkin already and my holdup is not being 100% on what to do about the driveshaft. My car is a 12' G37s coupe. At first I was all set to just buy a 6mt coupe complete driveshaft and have that installed. After talking with my mechanic he suggested that there may be a difference in size between the mating surface of the 6mt and 7at at the tranny. What exactly is my most convenient option outside dropping 600.00 on a one piece aluminum driveshaft? I've sent some pm's and hopefully I get the answers I need. Thanks for looking and if you can add please don't hesitate.

 

Hope this helps:
https://www.myg37.com/forums/engine-...hes-alive.html

SharpByCoop (great resource btw) suggested:

 

Thanks for the response Sam. I'm waiting on Coop to respond. I had read that but then I figured he had an 08' with the 4 bolt mid section on the driveshaft. Mine doesn't have that. I'm really hoping the spline on the two is the same. If not it looks like I may end up with a one piece shaft which will push my install back a couple weeks.

 

I just PM'd you, but there wasn't a mention of the non-sectional DS. So my response of only using the rear half won't work.

Does your 7AT NOT have a split mating? Or does the MT DS not have a split? Which one?

Place them side by side. Worst (Best?) case scenario you can press the universal joint bearings out and swap them that way. (Requires a good shop.)

Beyond that, this is new territory.

Coop

 

7at doesn't have the 4 bolt mating, 6mt does. If the forward spline of the 5AT tranny matches the 7AT I may still be in business. If the price stays below 400.00 for the package I'll piece one together, a penny over I'll bit the aluminum one piece bullet.

 

So this is becoming a PITA. Called PST and Mark is gone for 3 weeks. Waiting for Driveshaft Shop to call me back and I've been on the phone with local shops who probably think they're talking to someone with a tin foil hat and a dousing rod. Pretty amazing that NOBODY else has done this to a 12' 7AT.
Well........If you have a 7AT from 12' our problem is that the two piece driveshaft is linked by Universal joint instead of being a true two piece detachable by 4 bolts like in the early models. I also do not know for sure at this point but it's doubtful that the slip yoke on the front of the driveshaft is the same between the 7AT and 6MT . If it were the same it would be as simple as buying a 200.00 MT driveshaft and bolting up. I could also buy an 08' MT and an 08 AT for about 400.00 and swap the ends to come up with a
possible match, but then again I don't know if the 5AT slip yoke is the same as the 7AT.
Problem with that solution is that if I go to 400.00 I'll always know that for 250.00 more I could've had much better. I'm sure someone other than Sam or Coop has some interest in this c'mon folks help a brother out, even if it's just bouncing ideas around.

 

The length of the auto vs mt shafts might be diff. I think your best bet is to change the input pinion drive to the 3 flange to match your auto shafts. I saw this done on 350z forum.

 

THe reason I was confused is that I ASSumed you purchased a G37 5AT VLSD with the 3.69 gears. It's a bolt over. No driveshaft swapping.

Here's one at $350 delivered. http://www.ebay.com/itm/2008-08-INFINITI-G37S-COUPE-RWD-OEM-AUTO-LSD-REAR-DIFFERENTIAL-V36-VQ37-7049-/281325516248?pt=Motors_Car_Truck_Parts_Accessories&hash=item41804eb5d8&vxp=mtr
The 5AT auto versions are abundant and (seemingly) not so desirable, so they sell cheap. Dealing with the manual version is harder. MUCH harder.

Jim

 

Tell me about it..I've read your whole thread and I'm living it all over for you. I'm gonna go ahead and keep the pumpkin I bought and using your notes get the two 08' driveshafts and Frankenstein them together. I noted you used the rear half of a sedan 6mt and I was gonna ask why you didn't use a coupe. After I get it together I'll go with an aluminum solid unit just because I don't want to pay a 400.00 more for a 1 pound difference. Thanks for the help support Coop.
Anyone else considering this with a 7at would do well by choosing a 5AT pumpkin. You keep your own driveshaft and cut out at least one headache.
As my parts come in I'll update.

 

Could you link some pics or maybe ebay links of your current diff and what you are trying to upgrade to? I did a 09 g37x AT open diff to a vlsd without the need to replace the driveshaft. I may be able to help you.

 

Thanks for the reply. You really don't need a pic, I have a 7at but I bought a 6mt pumpkin for the upgrade to 3.69. The diff on my 7at has a three point flange. The 6mt has a round 4 bolt flange. When you upgraded to vsld you went with a 7at diff which gave you no change in gearing. Because you went automatic diff to automatic diff the driveshaft flange was a non issue. If you were to want to go with the more aggressive gears you would have to either switch to an 08 5AT vsld diff or endure my headache and go with a 6mt vsld. As it stands piecing together the 08 driveshafts will cost me just over 300.00 if it were more I'd simply sell the 13' diff I bought and just get an 08' vsld 5AT. That would void the driveshaft issue altogether.

 

That was not the case with me. Look at the picture below:


From the research i done when I was going this project the G comes with 3 different diff flanges for the 09. The 3 bolt, 4 bolt, and 6 bolt. I don't have experience with the 4 bolt unfortunately. However these flanges are interchangeable. The center nut need to be removed, but also measure how much torque it took to remove it. Then use a puller and extract the flange part. Swap the two flanges and torque the nut to your measurement.

Something to note:
Since your flange is 3 bolts, it uses the final drive shaft to center it to the drive shaft. The 4 bolt flange seems to use the center shaft for centering as well. If it uses the ball & socket type then you'll need a new drive shaft.

 

I'm on my phone so it's hard to post pics but the 6mt driveshaft uses a round lip on the flange to align. There is no centering pinion my guess would be the pinion is in support of the rubber coupling on the auto diff whereas the 6mt driveshaft uses the solid link with a u joint. Still the 5AT diffs available on eBay right now are a tempting proposal. The downside is it would seem that obtaining a one piece driveshaft down the road gets complicated with the 3 point flange.

 

A reminder that the three prong flange is for the rubber dampener on the AT's, and you NEED that pinion from the OEM Pinion gear to insert into the DS female bushing. If you don't, it will vibrate upon hard acceleration. Tell ME about it.

In Solidus' case, he needs to have the 4-bolt conversion, if possible.

Solidus: My prognosis: stop the bleeding. Don't order (2) driveshafts and labor for $800, without assurity. Order the solo unit above, and SELL the diff you already bought. Even at a loss it's a savings.

One piece DS is tempting but unnecessary. I never used one. reread my sig line. LOL!

Coop

 

Coop believe me when I say I read your entire thread. How about this........ The same place I purchased my 6mt pumpkin from has a 5AT vsld. I'm gonna try and see if I can drive over to Tampa and trade with them. If anything they come out on top getting a newer diff in exchange.