Is there anyone out there that has had this done? I just did and have about 200 miles since the install. I was wondering if there have been any issues that anyone has come across that might have more milage on them than myself.

 

Not 3.9..
I'm going with a small bump... 3.3 to 3.5 with a Quaife.

There have been some posts about loosing cruise control.
Did you have any problem?

 

Yeah cruise doesn't work... yet. The set light just flashes but we think there is a trouble shoot for it and can be re-set. Everything else is well worth it, I never use the cruise anyways.

 

gxclusive maybe??

 

I've had my set in for more than 10,000 miles...questions???

Rick

 

I've noticed that there has been a bit of a difference in downshift relative to speed. While taking a right turn, on a slow down not a complete stop, it seems like it will stay in 3rd lets say instead of dropping in to 2nd. I noticed this right after the install but it has since corrected itself, kinda weird. I have also noticed that the cruise control will work in lower speeds, 30-40 MPH but when you get to the 5th gear it just flashes "set". I am assuming that the ECU is most likely reading the speed/gear/RPM levels. Have there been any other issues you've seen like this regarding the automatic transmission?

 

Other than the cruise control - nothing. I actually noticed shifting improved a bit. The ECU, for cruise, get about 4 different reading for cruise control, the gears will mess up 3 of them...I've been working on a fix - but not luck thus far.

I have a racing trans in my car now - so not much to say otherwise. I ran the gears with the stock trans for 8000 miles without issue. I also noticed that shifting patterns in general improve when you downshift with the trigger engaged - not much noticed on the upshift.

Rick

 

I have noticed that it will shift right at redline as before it would shift about 200 RPM short. Overall I love the gears, huge improvement in response and acceleration. Did you use your stock diff or did you have to get a 6MT diff (I'm assuming you used the 350 Evo gears)? I bought a 350z diff assembly from a junk yard, I was able to upgrade to a LSD & 3.91, it was a huge difference.

 

Anyone with an AT HAS to get a the MT diff...no choice. The gear set are designed for the MT offset - which is not the same as the AT gear set - bad design in my opinion.

I got a used diff form 350EVO when I got the gears - not I have a full 2.0 Quaife diff...

Rick

 

What's the cost on switching up the gears? And do you have to replace the center section, or just drop in the 3.9's?

 

For an AT - about $1,800 plus labor to install. Estimate $2,600. If you can do it yourself...less.

Here's why - Assume the worst:

Gears and diff are about $1,500 (with seals, bearings and fluid)

Then you need Shims - but you wont know which ones until install - and they are a b...h! to find, if you can at all. SO - you have to almost literally buy them all ($500 and you'll only need about $60 worth of them and may not be able to return the unneeded ones), if your not buying a fully pre-assembled pumpkin for $1,800 + core + diff ($2,300), which by the way is the only REAL way to go.

Then you have to have a trusted shop to not only do the swap, but know how to shim the the gear set properly and no total out the set you just paid for.

I'm not trying to scare ya...jsut being VERY honest.

Do it right and buy and EVO pre-assembled unit and have it swapped in your car in less than a day at pretty much any decent shop. go the other route and your car will likely be down for a week or longer, cost you more money, etc etc,. The only real reason you would go the other route, is that you would want another diff that is not what is offered in the pre-assembled packages.


If you do a search for my alias - and look back about 6 months or so - you'll see a few threads I posted on with EXTENSIVE info on this subject.

Rick

 

Who did the work for you?

 

Rick thanks for all the input. I deal with a lot of gear changing, diffs, axles, shafts, etc. Only in the off road realm.

I dont know how much different this would be though. I have quite a few friends that do extensive off road work dealing with gearing and axles. That might be of use to me, dont know yet though.

I want to get some 20's soon, and I know regearing would help with the lose of power due to the 20's. It's all down the road, but Im storing up all the info for when the time comes

I'll be doing some searching, thanks for the info!

 

No prob..anytime.

Rick

 

Damn it, I was thinking maybe of going this route for some added pep for cheap, but looks like its not as much of a bragain as swapping out the gears in my previous car was. Damn you Infiniti for making the offsets different!!