Has anyone here done their own install of the 4.08 FD gears? I would really like to do it myself, but don't have any experience with rear ends. I know I need a shim kit. Is that something I could get from a dealership? Anything else I'd need? I have searched quite a bit, and really cant find anything other than the fact we need to drop the entire rear end to get the diff cover off, which is pretty obvious just from looking under the car.

 

I would recommend taking it to the shop for this one. Final Drive / rear end gears are kind of tricky to set the backlash just right, and set incorrectly, it will either whine, pop during turns, or cause massive damage to the bearings, gears, and even axle housing.

Should only be a few hundred bucks for an install, if you supply the gears and lube. Depending on your miles, you may need a bearing/seal kit as well and could be same price to install all while they are in there.

Even though I usually try do everything to my cars (supercharge installs, clutch change, transmission change, drive shaft changes, brake rotor/line/pad changes, alternator/battery/starter/injector/fuel pump/etc changes, re-upholster all seats with Katzkins, total stereo systems, etc) there are three things I don't do myself and leave it to the pros:

Tint windows, Dyno tune, and gear changes.

4.08 is pretty low, let us know how you like it when you are done. Your highway RPMs are going to be pretty high, but you should come off the line pretty good. There are calculators online that will tell you what your new RPM at redline and new RPM and XX MPH is going to be in each gear.

 

Yeah, off the line will be pretty outstanding, but what kept me from doing it is the hwy rpms are ridiculous. It would basically be 1000rpm over what's happening now. 80mph would be resting around 4krpm. I drive too much to deal with that kinda gas. Haha

 

Yeah I read on my350z that 70mph was about 3600 rpm. Its a bit high, yes, but this isnt my daily driver, so it may be tolerable. I was really hoping to do the install myself, as I too do all my own wrenching. But, since I've never been in there before, perhaps I should take Hatchman's advice and let the pros do it.

 

If its not your daily, then do it. It would be awesome. Launch like a bat outta hell.