4.6 reverse cut gears=EXPLODING diff?

[helix13]

When using the Pathfinder/xterra/qx4 front ring and pinion like everone is suggesting to do in order to swap in 4.6 ratios... Did anyone notice that they are reverse cut and aren't designed to be driven under power in this manner? I have front diff from a 99 QX4 and they are 100% reverse cut from stock. no one has ever made any comment on this issue, but shouldn't this setup simply explode after a short period of time???????

[G-E]

Did yours explode?

[helix13]

nope, I was waiting to find out what others have had for experiences prior to install.

[compactfean]

Nobody has done it....I guess you'll be the first.

[asoomal]

Ya, you're not supposed to do that, the contact pattern won't be right.

[helix13]

Thats why i stopped as soon as i saw that, my common sense was telling me that it was wrong. I just can't believe that nobody else has ever posted about it. So what is the highest numerical gear ratio that is possible for the r200? Is it the 4.375 from a R32 skyline diff like "Compactfean" suggested on another post?
Thanks for the info everyone...

[asoomal]

Nissan does make a 4.6 set.

http://www.frsport.com/Nissan-Final-Dri ... 16345.html

[helix13]

Ive seen that part from FRsport and have talked to them about it. Those definetly wont fit in a RWD application due to also being reverse cut. They removed the pricing from the web page for this reason. The reverse cut gears look identical to that image link with the teeth slanted towards the left if viewing the 12 O'clock area. ( top \\\ )
I do appreciate the help with the link though I found another link to some other custom sets from Japan, but they are listed for $1500+ not including shipping. YIKES!

[compactfean]

That is why when In search of a short ratio I settled for the 4.08 gears for my q45 setup. Otherwise from what I've found to be a realistic affordable diff. I would have done the 4.36 skyline diff but wanted the stronger axles from the q45/z32tt.

[MY1PATH]

It may only be certain years and models that are reverse cut.
Reverse cut was not always used in the front on 4wd vehicles because they do not see full time use.
AWD and FWD vehicles on the other hand should always be reverse cut up front.

[helix13]

Yes, you are correct...sort of, i will clarify for everyone. This answer took over a year from my first post to answer correctly.
After failing to find answers here or any other 240sx forum, I contacted a 4X4 shop in Utah that was able to shed a lot of light on the subject. The answer was there are actually two types of ring and pinions within the front diff of an Xterra. They are called a "high pinion" and a "low pinion". The low pinion is the older type of diff in which the pinion shaft makes contact on the lower side of the ring gear driving the vehicle forwards. In an upgrade from Nissan in model years 87 and newer the pinion was moved to the high side of the ring gear and then reverse cut to drive the vehicle forward. Otherwise, without the reverse cut on the high pinion, the front diff would drive opposite of the rear diff. This switch from low pinion to high pinion was made to result of gaining ground clearance in the 4X4 application. The LOW PINION (1987 and older)is the type we want to install in the rear diffs of our 240's. The low pinion installed in the rear diff will absolutely work. I have seen just about every spreadsheet that anyone has posted on here about the xterra gear sets and they are not 100% correct. They failed to mention ANYTHING about the high VS low pinion facts. I was able to put a 4.636 final drive on my 90 KA without new axles or carrier swap of any sort. It only required the proper shimming. Swapping to this ratio is simple and easy once the correct information is provided. I believe that is another other ratio available, (4.3 i think) in the same years of xterra. Looking at the vin plate in the engine bay of the passenger side it will tell you what the ratios are. The auto trans has the 4.636 that i used. the Manual trans has the 4.3