Nissan 370Z Forum - VHR + FD Gear Ratio upgrades

Nissan 370Z Forum (http://www.the370z.com/)

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- - VHR + FD Gear Ratio upgrades - 3.9 and 4.08 (http://www.the370z.com/engine-drivetrain/3658-vhr-fd-gear-ratio-upgrades-3-9-4-08-a.html)

Quote:

Originally Posted by Zat_Zuma (Post 926276)

No matter what they say about gear whine being within specs, its bogus.
The backlash (pinion gear) is out and needs to be redone. The amount of different shims available for the diff makes the excuse given; bogus. The adjustments are time consuming and require very meticulous measurements. My diff had zero issues and no whine at all until I broke it.
The clearances were done to my specifications and the backlash was perfect. It took the master technician a full day to rebuild it and to get it right.

With the 4.083 gears the clearances and backlash must be better than factory specs or you will get a small amount of gear whine. Compare the factory specs on a frontier with 4.083 gears, 350Z with 3.5 gears and our 370Z's with 3.7 gears and look at the differences.

But since you trust your shop and seem to be happy with their work, I really don't see why you are complaining if your leaving out imortant info and are satisfied with what you have.

"until I broke it" You need 600h.p + wide low air pressure slicks & come out of a standing start at over 6,000 rpm to maybe break a well installed ring & pinion set. What I'm saying is obvious, so I'll leave it there.

What is this?

Better late than never at all

Sorry, but I've been trapped in a time warp

That was written in 2011, Feb

Where the frick have you been???

Quote:

Originally Posted by Zat_Zuma (Post 2549720)

What is this?

Better late than never at all

Sorry, but I've been trapped in a time warp

That was written in 2011, Feb

Where the frick have you been???

I went from last back :)

Hi,

Does anyone know what the correct space between the gears should be? Without this info, I won't know how much I should shim.

Please advise.

Thanks.

Quote:

Originally Posted by blumango (Post 2566739)

Hi,

Does anyone know what the correct space between the gears should be? Without this info, I won't know how much I should shim.

Please advise.

Thanks.

I have no clue but if I were you I would take it to someone who knows what they are doing. I know if you don't have the backlash set right you will have catastrophic failure. Just my $0.02

Sent from my iPhone using Tapatalk

I'm well aware. But I can't find some one in Singapore who has done this mod. If I can have these info, I can advise them and they can measure and shim accordingly

Got the Quaife on order. Can someone verify this is the OEM ring and pinion gear set I need to order from my local dealer? It is going into a 6M Diff.

M/T w/15" wheels = 4.083 = part number 38100-0C760

Quote:

Originally Posted by wstar (Post 59365)

Yeah that's a concern for me too. In the 7AT our rear end is even worse ratio than you 6MT guys (7AT is 3.357, 6MT is 3.692). However, at the speeds I like to cruise at on the highway (when possible), I don't want the revs going any higher in 7th than they are now. 7AT really could use an 8th gear (or just taller transmission gearing in 6 and 7 both) for us high-speed cruisers :p

i'm a new member & have been looking over a lot of pages,,,,i am wanting to swap the 3.36 diff from my base/auto 370 for a 3.69 manual diff..
top end would still be the same-just closer to the 7500 redline in 5th.
currently limits out at 7k in 5th-showing 158mph on speedo.
dont drive like that a bunch/but it's an adrenaline rush!
has anyone done this and does it affect the traction control or cruise.
thanx for any imfo.

Quote:

Originally Posted by jchammond (Post 3098402)

I swapped the whole pumpkin from a manual 3.69 VLSD on my 7AT with the Z1 rear diff kit and my car runs much better and torquier! This swap did not affect anything on my car and everything works normal.

This is one of the best Mods you can do :tup:

What is the main difference in the gears?

Did any one else who did this swap have the ABS and Traction slip lights come on after install? I've had it checked by Nissan and they said they found the lights and codes but couldn't find anything wrong. I did the gear swap and switched from open to the VLSD at the same time. The only thing I didn't replace was the drivers side output shaft, I had the passengers side ground down.