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Tech: Regearing Nissan R180A, M205, and M226 Differentials

Regearing Nissan R180A, M205, and M226 Differentials

Hey guys!

This will be a living document / brain dump and will grow as more content is added to it.  It'll initially start out as a parts list reference for master rebuild kits as these are becoming scarce from the big names and it's becoming necessary for users to piece them together individually.  The conversation is mostly oriented around the Nissan 4x4 midsize applications from 2005 to present (Frontier, Xterra, R51 Pathfinder) but some information is also applicable to the full size applications (Titan, Armada).

If you've chosen to run larger tires on your Nissan 4x4, you may have noticed that the vehicle is a little more sluggish "off the line", has a little less "get up and go", or frequently downshifts / gear hunts when using cruise control.  The reason for this is when you change tire size, you're affecting your "drive ratios".  Your drive ratios can effectively be though of as the transistions which occur from engine crankshaft -> transmission -> transfercase -> differentials -> tires.  Through these transisions power output from the engine crankshaft is modified so that a driver has useable power to get their vehicle moving; most often multiplied through ratio reductions: for instance, three turns of the engine crankshaft to one turn of the transmission output shaft in first gear (3:1).  The functional purpose is to increase torque, the result of which is higher required engine rpm's.  

A 4x4 vehicle generally has 4 different components which affect drive ratios - 

  1. Transmission
  2. Transfercase
  3. Front & Rear Differential Gearset
  4. Tires

1. Transmission:

In an 05-19 Nissan midsize 4x4 like the Frontier, 05-15 Xterra, 05-12 R51 Pathfinder and full size Nissan Titan and Armada sold in the USA, you'll commonly find the Jatco 5R05 five speed automatic transmission or the six speed manual transmission.  

  5 Speed Automatic 6 Speed Manual
1st 3.84:1 4.37:1
2nd 2.35:1 2.52:1
3rd 1.53:! 1.74:1
4th 1.00:1 1.28:1
5th .84:1 1.00:1
6th N/A 0.77:1
Reverse 2.77:1 3.54:1

Specific to the Nissan Frontier, in 2020+ models Nissan began using a new 9 speed transmission.  I believe the same applies to the 2020+ Nissan Titan

  9 Speed Automatic
1st 5.42:1
2nd 3.26:1
3rd 2.25:1
4th 1.65:1
5th 1.22:1
6th 1.00:1
7th 0.86:1
8th 0:71:1
9th 0:60:1
Reverse 4.80:1


2. Transfercase:

These vehicles were commonly equipped with a selectable two speed transfercase.  The High speed is 1:1 and is what a driver will normally use in 2wd or 4wd.  The Low speed is 2.63:1 and would be used for offroading for torque / power multiplication at the sacrafice of reduced speed.  

3. Front & Rear Differential Gearset:

A variety of ring and pinion ratios came on these vehicles from the factory.  Common automatic transmission ratios are 3:13:1 and 3:36:1.  Common ratios for manual transmission equipped vehicles are 3.54:1 and 3.692:1.  

4. Tires:

Most commonly, the Nissan midsize applications were equipped with a 265/70r16 in non-Pro-4x trims and 265/75r16 in Pro-4x trims or equivelant; depending on the wheel size equipped to the vehicle from factory. 


Modifiying any one of these four components will have an impact on the ability of your engine to adequately accelerate and power your vehicle.   The most common modification by far which affects drive ratios is an increase or decrease in tire size.  For offroading purposes, we run lift kits so that we can run larger tires - larger tires improve under-vehicle clearance, approach angles, and improves the ability of the tire to roll over larger cracks and crevices than a smaller tire.  For these benefits gained, there is a cost to adding larger tires: increased tire circumfrence and increased weight - both of which affect drive ratios and the felt power of the vehicle.  To correct a change in drive ratio by stepping up to larger tires, the easiest of the three remaining components to modify is your front and rear differential gearset.  Modifiying the ratio of your ring and pinion will allow you to restore your factory drive ratios or even slightly improve them.  Choosing the correct ring and pinion ratio is very easy to calculate using an online calculator.  I like the calculator found HERE.  It's easy to input and compare different tire sizes and ring and pinion gear ratios to see how it affects vehicle RPM at given speeds.  

Most common to the applications we are currently covering, a person will choose to run a 33" equivelant tire like a 285/75r16 or a 285/70r17.  For demonstration purposes we will choose an 05-19 Nissan Frontier Pro-4x with an automatic transmission.  From factory this vehicle would be equipped with 265/75r16 tires and 3.36 gearsets.  I generally like to choose the top gear of a vehicle - this is normally an overdrive gear and will be a good representation of the engine working at it's hardest.  For the Pro-4x Frontier this would be "0.84".  

Here's a representation of different tire sizes and how they affect speed at given RPM's in overdrive with the 3.36:1 gearset:

  265/75r16 @ 3.36:1 (Factory Tire) 285/75r16 @ 3.36:1 (33" Tire) 315/75r16 @ 3.36:1 (35" Tire)
1000 RPM 33.36 MPH 34.61 MPH 36.47 MPH
1500 RPM 50.04 MPH 51.91 MPH 54.71 MPH
2000 RPM 66.72 MPH 69.21 MPH 72.95 MPH
2500 RPM 83.40 MPH 86.51 MPH 91.18 MPH
3000 RPM 100.08 MPH 103.82 MPH 109.42 MPH
3500 RPM 116.76 MPH 121.12 MPH 127.66 MPH

Here's a representation as above with 3.692:1 gearset:

  265/75r16 @ 3.692:1 (Factory Tire) 285/75r16 @ 3.692:1 (33" Tire) 315/75r16 @ 3.692:1 (35" Tire)
1000 RPM 30.36 MPH 31.49 MPH 33.19 MPH
1500 RPM 45.54 MPH 47.24 MPH 49.79 MPH
2000 RPM 60.72 MPH 62.99 MPH 66.39 MPH
2500 RPM 75.90 MPH 78.73 MPH 82.98 MPH
3000 RPM 91.08 MPH 94.48 MPH 99.58 MPH
3500 RPM 106.26 MPH 110.23 MPH 116.18 MPH

Here's a representation as above with 4.10:1 gearset:

  265/75r16 @ 4.10:1 (Factory Tire) 285/75r16 @ 4.10:1 (33" Tire) 315/75r16 @ 4.10:1 (35" Tire)
1000 RPM 27.34 MPH 28.36 MPH 29.89 MPH
1500 RPM 41.01 MPH 42.54 MPH 44.84 MPH
2000 RPM 54.68 MPH 56.72 MPH 59.78 MPH
2500 RPM 68.35 MPH 70.90 MPH 74.73 MPH
3000 RPM 82.02 MPH 85.08 MPH 89.67 MPH
3500 RPM 95.69 MPH 99.26 MPH 104.62 MPH


When choosing gearset ratios, I like to slightly underdrive from the factory numbers to account for added tire weight.  Most offroad tires are 10 ply and will be noticeably heavier than a factory 6 ply tire when sitting in the driver seat.  A heavier tire makes the engine work harder, as does a larger tire diameter.  A slight underdrive will also improve your crawl ratio when your transfercase is in 4Lo.  

My general recommendations are these when considering gears on an 05-19 Frontier, 05-15 Xterra, or 05-12 R51 Pathfinder with an automatic transmission and larger tires - 

33" - 3.692:1
35" - 4.10:1

For 05-19 Frontiers and 05-15 Xterras with a manual transmission, my recommendation would be as follows - 

33" - 4.10:1
35" - 4.56:1

When regearding a Nissan midsize 4x4 to a deeper (numerically higher) gearset - it would be ideal at the same time to swap out the R180A front differential for the M205 front differential found in the 03-15 Nissan Titan and Armada.  It is a stonger differential than the R180A with stronger corresponding CV axles and will better withstand the increased torque which is created with deeper gearing.  CV axles can be sourced from the V8 equipped Nissan R51 Pathfinder if you're not planning on a titanswap suspension.  The M205 is direct bolt-in upgrade for a user with an R180A axle, so long as the gear ratio is matched to the rear and corresponding CV axles are sourced.  


Nissan R180A Front Differential 

  • Applications -
    • 2005-2023 Nissan Frontier (2005-2019 27 spline inner CV; 2020-2023 30 spline inner CV)
    • 2005-2015 Nissan Xterra
    • 2005-2012 Nissan R51 Pathfinder (v6 models)
    • 2018-2019 Nissan Armada (30 spline inner CV)
  • Carrier Break - 3.54 Down / 3.692 Up
  • Notes -
Item Qty Required Nissan OE P# Aftermarket P#
Carrier Bearing / Race 2 38440-EA000 Timken 30208;
Carrier Shims 1 N/A Yukon SK-D35JL-CARRIER-RH
Pinion Front Bearing / Race 1 38140-EA000 Timken 32207
Pinion Rear Bearing / Race 1 38120-EA000 NSK R32-39; Koyo 332/32JR; NTN 332/32
Pinion Shims 1 N/A SKT8
Pinion Nut 1 38216-U301A  
Pinion Crush Sleeve 1 38166-EA000  
Ring Gear Bolt   38102-12S00  
Pinion Seal 1 38189-AR00A  
Drivers Side Seal 1 38342-EA000  
Passenger Side Seal 1 40227-EA000  



Nissan M205 Front Differential 

  • Applications -
    • 2003-2015 Nissan Titan
    • 2004-2015 Nissan Armada
    • 2008-2008 Nissan R51 Pathfinder (v8 models)
  • Carrier Break - N/A
  • Notes - Not a lot of traction device options - ARB airlockers are available and TJM recently started manufacturing an elocker.  
Item Qty Required Nissan OE P# Aftermarket P#
Carrier Bearing / Race 2 38440-8S110 LM603049 / LM603011
Carrier Shims 1 N/A N/A
Pinion Front Bearing / Race 1   M88048 / M88010
Pinion Rear Bearing / Race 1   M802048 / M802011
Pinion Shims 1   SKT8
Pinion Nut 1 38216-8S11A  
Pinion Crush Sleeve 1 38165-8S110  
Ring Gear Bolt   38102-8S110  
Pinion Seal 1 38189-8S110 710920
Drivers Side Seal 1 38342-8S110 710919 
Passenger Side Seal 1 38342-8S110 710919 


Nissan M226 Rear Differential, Gen 1 (2005-2019)

  • Applications -
    • 2005-2019 Nissan Frontier (Nismo, Pro4x trims)
    • 2005-2015 Nissan Xterra (Offroad, Pro4x trims)
    • 2003-2015 Nissan Titan
  • Carrier Break - N/A
  • Notes - This diff uses the same ring and pinion as a corresponding 07-18 JK Jeep Wrangler Rubicon.  The Rubicon factory 4.10 gears for elocker are thick-cut like Nissan M226 gears for elocker and should bolt in without the need for a ring gear spacer.  This applies to aftermarket gearsets, only if they are labeled as "thick cut".  


Item Qty Required Nissan OE P# Aftermarket P#
Carrier Bearing / Race 2   JLM704610 / JLM704649
Carrier Shims 1 N/A N/A
Pinion Front Bearing / Race 1   HM803146 / HM803110
Pinion Rear Bearing / Race 1   M88010 / M88048
Pinion Shims 1   55009
Pinion Nut 1 38216-8S10A 30271
Pinion Crush Sleeve 1   Dana 46925
Ring Gear Bolt     Yukon YSPBLT-006 / Dana 2003431
Pinion Seal 1 38189-ZJ00A DANA 2004101


Nissan M226 Rear Differential, Gen 2 (2020-Present)

  • Applications -
    • 2020-2023 Nissan Frontier (All trims)
  • Carrier Break - N/A
  • Notes - Starting in 2020 it appears Nissan has made changes to the head and tail pinion bearings used in this differential.  Master rebuild kits for the previous generation of M226 are not compatible.  There may also be carrier bearing changes, which will be verified shortly.  Axle shafts, wheel speed sensors, wheel bearings, and seals all appear to have carried over.  


Item Qty Required Nissan OE P# Aftermarket P#
Carrier Bearing / Race 2   NP775796 & NP792716 (proprietary Timken p#, not currently available)
Carrier Shims 1 N/A N/A
Pinion Front Bearing / Race 1   NP227266 / xxxxxxxxx (still researching)
Pinion Rear Bearing / Race 1   NP966883 / NP759177
Pinion Shims 1   55009
Pinion Nut 1 38216-8S10A 30271
Pinion Crush Sleeve 1   Dana 46925
Ring Gear Bolt     Yukon YSPBLT-006 / Dana 2003431
Pinion Seal 1 38189-ZJ00A DANA 2004101


Last updated - 8/30/2023

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1/11/2023 6:57 PM
For the M226 rear diff applications it might be pertinent to add manual transmission vehicles for the Xterra and Frontier; regardless of trim model. Otherwise - super detailed and informative guide. Thanks guys!