Info in changing gears in front differential

[Rob T]

Thanks for reading. I bought a front diff with 55,000 miles from a titan. I called the nissan dealer and she told me it had the 3.36 ratio from the vin #. After buying it and getting it home I checked the ratio and it's the 2.94 ratio. With nothing else locally I bought one off ebay. The first one that I bought had more slop than mine so after complaining about it the company sent me another one. It was nice and tight and no signs of past oil leaks. I installed it yesterday and as I went to bolt up the axles I noticed the housing was cracked by the passengers side axle tube bolts. I emailed him again and he told me he would refund my money. So I really want my car so I can use it and got to thinking that maybe I could change the main gears from the broken diff to the good one. Anyone know if this would be a good idea, and how hard is it to do it? Does it require a degree in bearing load and $1000.00 in special tools? Should I just have the nissan dealer do it? I don't have an infinity dealer withing 200 miles, so Nissan is my only choice.
Thanks for any help.

 

[primov8]

Not sure what specific tools would be needed but if swapping out to a completely different gear ratio, the ecu has to be reflashed. The ecu reflash is needed to change shift points to accommodate the different gearing and read the correct MPH. I remember years ago on one of the Titan forums, someone had mentioned a new speed sensor would be needed too.

 

[Rob T]

I'm looking to keep the same ratio in car but need to swap the gears into another housing.

 

[primov8]

It can be done but there are specific tools for the ring and pinion gears. Those tools are needed in order to set them up correctly inside the differential housing.

______________________________

 

[Rob T]

I figuired that that would be the case. I'll see if Nissan will do it, and how much.
Thanks.

 

[primov8]

I’d look around for a shop that specializes in drivetrain work. Considering you’re not doing anything custom, swapping out the internals from one housing to another shouldn’t be a problem for drivetrain specific shops.

 

[Rob T]

We don't really have anyone around like that. Don't even have a transmission shop.