Thanks for the VIN
@Cossack . Here's what I can tell you:
- Parts.nissanusa.com and vindecoderz.com both show it as an LE, though not too relevant here. Main thing to know was engine, cab configuration, drivetrain, and transmission to determine axle and gear ratio.
- NissanPartsDeal.com lists the axle as being the C200, but you should be able to confirm by comparing pics of the bolt pattern of the diff cover.
- The 2008 FSM indicates that your truck has 3.357 gears, which is p/n 38100-0F36A (replaces 38100-2C360, 38100-1C360, 38100-0B36A) and appears to still be available new from Nissan for $700. These links below will show you all Nissan and Infiniti vehicles that had those gears:
- Notably, all of those Nissan and Infiniti vehicles listed, all but the Frontier use the R200 differential, which is a stand-alone differential with detachable CV axles. There's plenty of them on eBay, and they would also have the spider gears and probably several other parts that could be used in your truck, and would be far easier to ship.
- The spider gears, p/n 38425-21W0A (replaces 38425-21W00) listed previously, appear available from Nissan for $41/ea
Did the mechanic indicate if the R&P gears were scored from the damage/debris, or just in general? How many miles does your truck have? Unless a chunk of material actually got crushed in the teeth (and carnage ensued), or if a smaller piece produced a sizable pit or chip on ring or pinion teeth, I wouldn't bother with them. The side gears may be another story since they're in direct contact with the spider gears, so those should be closely inspected.
Again, if
actual damage is just limited to a busted spider gear, this repair is simple. If the mechanic continues to push a more complicated route without physical or visual proof, I'd be cautious.
In hopes of further demystifying this issue (i.e., presuming damage is limited to spider gear), this is basically what you're up against...
Busted spiders gears might look something like this (this is a Nissan H190 3rd member that came from one of my trucks):
Beyond the initial 'bang' that causes the teeth to sheer off, additional bangs are usually from the side gears trying to engage into the remnants of the side gears, which may or may not be turning (depending if your truck is turning or going straight, respectively).
To remove the carrier, you pull the axle shafts out about 2", undo the carrier cap bolts, and pull/pry the carrier out (holding the carrier stationary and rotating the pinion also helps). Shims (hidden by the caps) will come out, too; keep everything on the correct sides (i.e., left side vs. right side).
With ring gear removed, your carrier will look similar to this (this is a pre-MY05 R200/C200 2-pinion open carrier):
The spider gears shown on the pinion/cross-shaft, side gears at top and bottom. The side gears shown are the exact ones you'd need.
The ring gear gets removed because it'll likely obstruct removal of the cross-shaft, spiders, and side gears. A long nose punch through this hole on the ring gear bolt side will push the roll pin (p/n
38428-U1500, should be replaced with a new one) out of the cross-shaft.
Push the cross-shaft out of the carrier, then rotate a side gear and the spider gears will just roll towards the opening along with some thrust washers. Clean everything, apply some gear oil to all friction surfaces, and reassemble. The
2008 FSM has all the torque specs in the Driveline chapter, C200 section (ring gear bolts: 58 ft-lbs then 31°-36° extra rotation; bearing cap bolts: 69 ft-lbs).
Again, no gear setup is required because nothing relating to the gears should have changed. Of course, if the R&P do need replacement, then it'll need to be setup correctly. The FSM has those instructions.