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RoadKiller2006's 2wd to 4wd Conversion - PBR

20087 Views 54 Replies 19 Participants Last post by  Old Navy
Hello! This is my 4wd Conversion Project Thread. I've wanted to convert to 4wd ever since I found TNX Website, and while buying another truck is easier, building it yourself is a lot more fun! I'm also lifting my truck from 2" to 3-4" at the same time.

This thread will follow many of the same steps as what @USMMA11NC, @germandude890, and x_mods from clubfrontier did to convert their 2wd to 4wd, but I figured, more is better.

(Update 01/13/18:) Unfortunately, 'x_mods' thread did not survive the "Photobucket Ransomware Disaster".

First Off - The Parts List: (Note: I included the prices that I paid for reference if anybody else wants to do this conversion.)

Mod Group | Part Nomenclature | MFR & Part Number | QTY | Total Price Front Differential |
|Wheel Bearings/Hubs | Timken SP450701 | 2 | $271.16
|Front Axle Nut (32mm)|Nissan 40262-2Y00A|2|$4.60
|CV Axles|Nissan 39100-EA000|2|$50
|Front Differential (3.36)|Nissan 33100-EA33A|1|$400
|LOKKA locker|Lokka NIS-FO-61|1|$0 Was already in diff
|Differential Bracket LH|Nissan 50333-7S031|1|$21.92
|Differential Bracket RH|Nissan 50332-7S031|1|$21.92
|Differential Bolts|Nissan 54726-7S000|3|$16.02
|Differential Nuts|Nissan 08918-3442A|2|$3.44
|80W-90 (1-3/4 Qts)|Valvoline 831|2|$17.98
Front Driveshaft |
|Driveshaft|Nissan 37200-ZP90A|1|$61
|U-joints|Spicer 5-1310X|2|$42.26
|Front Driveshaft Bolts|Nissan 37120-4P00A|8|$14
|Front Driveshaft Nuts|Nissan 37171-7S00A|8|$10.40
Transmission |
|Transmission Assembly 4x4|Jatco RE5R05A|1|$847.00
|Transmission Filter/Gasket|ATP B-372|1|$14.34
|Front Oil Pump Seal|Nissan 31375-4AX02|1|$5.60
|Matic S (10-7/8 Qts)|Nissan 999MP-MTS00P|11|$95.50
|Washer Seals Oil Cooler Lines|Nissan 21626-32U00|4|$2.96
|Charging Pipe O-ring|Nissan 31084-20301|1|$3.40
|Charging Pipe Gasket|Nissan 31397-90X01|1|$4.32
|Charging Pipe Self-sealing Bolt|Nissan 31377-JL01A|1|$2.41
Transfer Case |
|Transfer Case Assembly|Nissan 33100-EA33A|1|$95.97
|Rear Seal | Nissan 33140-7S110|1|$13.59
|Rear Dust Cover | Nissan 33141-7S11A|1|$11.34
|Transfer - Transmission Bolts|Nissan 08124-0451E|14|$15.13
|Rear Insulator Mount|Nissan 11320-9CA0A|1|$112.14
|Matic D (2-1/8 Qts)|Nissan 999MP-AA100P|3|$29.25
Rear DriveShaft |
|Rear Driveshaft|Nissan 37300-ZP71A|1|$100
|U-joint|Spicer 5-1330X|1|$11.25
|Rear Driveshaft Bolts|Nissan 37120-0P00A|6|$7.92
|Rear Driveshaft Nuts|Nissan 37171-7S00A|6|$7.80
Rear Axle |
|M226 (3.36 - Elocker)|Nissan 43003-9CL0C|1|$700
|U-bolts|Pro-Comp 13-90334A|4|$51.96
|75W-140 (4-1/4 Qts)|Mobil 1 102490|5|$89.75
|Ballistic Fab Cover|Ballistic Fabrication DIF-2018-2|1|$110.50
|E-brake Shoes|Monroe BX869|1|$19.20
|E-brake Spring/Hardware Kit|Carlson 17400|1|$10.34
|Breather Nipple|Nissan 38323-C601A|1|$5.29
Misc |Wiring, Arduino...|||$126.3
Shipping ||||$558.28
Discounts |Amazon Gift Cards, Discounts through NORSE..|||$-408.16
Total ||||$3,608.95

My Truck has 80k miles
The Front Diff has approximately 70k
The 4wd Transmission has 15k
The Transfer Case and Rear Axle have approximately 100k

I chose to replace the Transmission Filter and Front Seal because LKQ's Warranty will be void if not replaced.
I also chose to replace the Rear Seal and Dust Cover on the Transfer Case because it was Duct taped together and has been banged up during shipping.
All other Seals look good so far.

EDIT: I recommend changing every single Seal while everything is out. They're cheap and much easier to change while component is off the Truck. I've had to replace the Front Output Seal on the Transfer Case and the Front Driver-side Diff Seal was leaking slowly as well. The $50 for all Seals was well worth not having to spend hours under the Truck later on.

I chose to replace the U-joints since its easier to do it before installing them, and they will need to be done at some point so might as well do it now with new ones.

Now for the Lift:

Mod Group | Part Nomenclature | MFR & Part Number | QTY | Total Price Front Suspension |
|Front Adjustable Shocks (5100)|Bilstein 24-187053|2|$193.34
|Coil Springs|Moog 81280|2|$62.12
|Top Rubber Spring Isolators|Nisstec N-UBK|2|$54.14
|Top Mount Rubber Bushings|Included with above|2|$0
|Steel Top Mount Sleeve|Included with above|2|$0
|Top Coilover Washers|Included with above|2|$0
|Lower indented Coilover Washers|Included with above|2|$0
|Shock Top Bracket|Nissan 56115-EA001|2|$22.67
|2" Spacers + Bumpstops|PRG prg-2lk-x|2|$0 Already on truck
|SPC UCA|SPC 25540|2|$350
Rear Suspension |
|Single AAL|Deaver D10045L09|2|$99.00
|Rear Shocks (5100 3-4")|Bilstein BE5-6253-H5
|Shims 4 degrees *** |PRG Xterra shim|2|$44.00
|Rear Shackles|PRG prg-shkl-x|2|$0 Already on truck
Shipping ||||$22.19
Discounts ||||$-49.98
Total ||||$937.86

I bought new Springs because the 2WD Springs are 0.4" shorter at rest and may have a different Spring Rate.
I bought new Top Hats and such because I figured I might as well replace the Bushings and also for convenience since I can assemble the Struts before touching my Truck.
***I originally ordered 3 degree Shims, but PRG sent me 4 degree ones, so we'll see if they do the job.

Below are pictures of the parts. The Rear Axle / Driveshafts are not pictured yet. I'll post those pictures when I have them.

It's heavy...

The Plan
Since this is my Daily Driver, I can't afford many days of downtime at once. I will do this conversion step by step when possible.

My Plan Currently Is To Do:

1- Transmission - Transfer Case - Rear Axle
2- Front Differential
3- Wiring

Step 1 will be the biggest step. It will involve swapping the Transmission and Transfer Case in as well as the M226.
Since I'm 2wd currently, my C200k Flange only has 4 bolts. Since the M226 as well as the 4wd Rear Driveshaft have 6 bolts, I unfortunately can't run the new Transmission with my current Axle easily. This will also include installing the AAL in the Rear.

The second step will involve welding the Differential Brackets to the Frame.
I will then tear apart the Front Suspension to install: The new 4WD Hubs, the 5100s, the SPC UCAs and the CV Axles.
I can then fill the Front Diff with fluid and Drive the Truck like that. It will still be in 2wd since no Driveshaft will be connected to the Diff just yet.

This step will be the easiest since I already figured out how to control the Transfer Case without going trough any of the Factory Computers. I will post the Arduino Code once I test it in real life situations. So far I've only tested it with the Actuator out of the TC.
This will also include the wiring of various LED Indicators to ensure that everything is working properly.
I will also wire the Rear e-Locker in this step.

I won't have any progress for a few weeks since I'm going through finals and I'm still waiting on a few parts. I do have all the parts to complete Step 1 though.

If you see anything wrong / any part that I should have/replace that I don't have listed, feel free to let me know !

Thanks for reading
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Rear Axle

In this section we will talk about swapping the Rear Axle, installing the AALs, the new Shocks, as well as changing U-joints on the Rear Driveshaft. I've included the Driveshaft in this section because I feel like this is where it belongs even though it won't be put in until the Transmission/Transfer Case go in.

Step 1: Gather and Inspect all Replacement Parts

I cannot stress this enough, inspecting is the most important part of the job. The last thing you want to do is swap the Axle and learn that you have the wrong ratio, have a bent Axle Shaft, have destroyed Gears... I didn't do this, but you should replace all Seals no matter how good they look. (Ask me how I know lol.)

Back to inspecting, it's hard to see in the pictures, but the rear had a good amount of Rust on the housing. The cover was very crusty, the Backing Plates had a couple holes in them, and the Brake Lines had seen better days. The inside was in good condition however, which is the most important part.
This is what I checked when I opened it up:

- Correct ratio: Turn the Ring Gear until you see numbers engraved on its side. For a 3.36 Ratio the numbers should read 47-14. 47 is the number of Teeth on the Ring Gear, while 14 is the number of Teeth on the Pinion. So 47/14 is 3.357.

- Condition of said Gears: Cracks, chips and rust on the inside of the housing. I also removed the Breather and shined a light inside there to check for rust.

- Trueness of the Axles. You want to make sure you don't have bent Axle Shafts. Make sure they're good.

- Try the Locker: If your new Axle has a Factory Locker, take a 9V Battery and touch it to the Blue and Grey Wires coming out of the Axle. You should hear a pop and visually see a Flange move 1/4-1/2 inch on the inside.

- Generally inspect the outside: While doing this I found that the Hard Brake Lines had a little more rust than I was comfortable with, and that my e-Brakes were missing a Spring.

- Now also inspect the driveshaft: The major thing to look for here is the cleanliness of the Slip Yoke. This part has to be clean, smooth, and without rust because this is the part that moves in and out of your Transfer Case while also rotating. If this part isn't good, your Transfer Case will leak. My Yoke was fairly clean, I did use 3000 Grit Paper to make it 100% clean and smooth. As long as it doesn't have dings or rust pits you should be able to clean it up. Also look at the CV Joint at the back of the Driveshaft. It is serviceable contrary to what Nissan says, but it's expensive so look for tears in the Boot. You can also look at the U-joint, but you should replace that no matter what. They're less than $20 each and it's not worth having one explode, because it went dry and destroy a lot of expensive parts.

Now that we've made sure the parts we got are use-able, we need to correct anything that is not up to standards before installing them.

For me, this meant cleaning up and repainting the Axle. The pictures that follow are just that.

I cleaned up the Axle with a Wire Wheel and a Grinder before spraying Primer, and finished with a Black Enamel Paint. I also recommend using massive amounts of Brake Cleaner over the entire Axle. I also installed a Ballistic Fab Cover, since the old one was beyond saving, and their covers are great. I also tried my best to bend back the Backing Plates before painting.

As you can see, the old Brake Lines and e-Brake Cables are also gone. I will reuse my current lines since they were rust free.

Now is also a good time to prepare the Driveshaft. The paper towels wrapped in Electrical Tape in the pictures is to protect the Slip Yoke from scratches and dirt.

Step 1: Use a U-joint Press to press the old Bearing Caps out. Make sure you mark the Yoke and the Body before removing the U-joints to make sure they go back in the same direction. This will make sure it doesn't get put back together the wrong way and throw off balance.

Step 2: Press the new U-joint back in, making sure the Needles go in straight. Press the Caps far enough to see the retaining groove and insert the Clips.

Step 3: Inspect the 4 sides, and make sure the Clips are in place. If the U-joint is hard to move by hand, tap all 4 sides with a Hammer to relieve the pressure.

Now lets get to the fun part, which is getting the C200k out, and the newly painted M226 in: :)

Step 1: Disconnect the Battery. It may not be necessary, but since we will be disconnecting ABS Sensors for extended periods of time, and possibly splicing wires, I didn't want to take any chances. While you're up front, Chock the Wheels.

Step 2: Disconnect the Driveshaft. Mine was a 4 bolt, and the bolts were on there very tight. I decided to take the U-joint off instead and deal with the bolts when the Axle was removed. Remember that without a Driveshaft, the only thing holding your Truck in place is your e-Brakes.

Step 3: Get the Spare Tire out of the way so you have more space to work.

Step 4: Disconnect the ABS Connectors. There are a lot easier to disconnect than the Front ABS Sensors. Just stick a Flathead in there and push/twist in the plug. They'll come out easily without risking cutting wires.

Step 5: Jack up the Truck and secure it on Jack Stands. Make sure you Chock the Front Wheels since nothing will hold your Truck in place. Push on the Truck to make sure that the Stands are not moving. You will be spending a lot of time under the Truck.

Step 6: This step is kinda optional, but I was going to remove the Cover, (to sell), so I drained the Fluid of the old Axle.

Step 7: Remove both Shocks. Start with the bottom bolt. Shocks gave me problems on the removal and install, so maybe there's a better time than now to remove them?

Step 8: Remove your Tires, and Wheel Spacers if you have them. Remove the Calipers, (as entire assemblies, there's two bolts) and also remove the Rotors. You can rest the Calipers on the Leaf Springs for now, but put the Rotors in a safe place since you will be reusing them. I also took the time to unbolt the old ABS Sensors and remove them completely so I wouldn't damage them, (I also did that on the new Axle before painting.)

Step 9: Remove the e-Brakes. I bought new Shoes and Springs, but if you didn't, make sure you don't bend the Springs. You will want to push and turn on the two pins with a Flathead Screwdriver to pop the old Shoes off. Since I was reusing the e-Brake Cables, I had to disconnect them here. On the Clip assembly that retains the Cable, push out the metal pin, (DON'T LOSE IT, IT'S SMALL), to release the Cable. The Cable can be unbolted from the other side of the Backing Plate. Take the time to remove the Cables from the rest of the Axle, and push them out of the way.

Step 10: Remove the U-bolts. Now your Axle will only be attached to the Truck by the Brake Lines.

Step 11: Remove the Brake Lines from where the Lines go from soft to hard on the Axle itself. You will want some way of catching the Fluid coming out, as Brake Fluid is a b!tch. You will want to unclip the Brake Lines along the entire Axle and pull them out, (while keeping them attached to the Calipers.)

Step 12: Pull the old Axle out. To make this easy, I unbolted the bottom of the Shackles on each side.

Step 13: Since I was adding AALs at the same time, I found it easier to do while the Axle wasn't in the way. Clamp the Leafs, and remove the Factory Centering Pin. Vice-grips help to remove the Pin, as it is completely round on top. You will want to play around with the Clamps while inserting the AAL in-between the Leaf Pack and the Overload Leaf. The short side of the AALs goes in towards the front. I used a 4 degree Shim, but YMMV. Insert the new Center Bolt in, and Torque it down to whatever the place you got your bolt from recommends. Cut the end of the bolt if it's sticking out a lot. Mine was barely long enough to thread the nut on, so I didn't have to cut.

Step 14: Wheel the new Axle over the Leaf Springs, and reattach the Shackle to the Leafs. Torque down to 77ft-lbs.

Step 15: Lower down the Axle onto the Leafs, making sure the ends of the Centering Bolts go into the holes in the Spring Perches. At this point you can install the new U-bolts. I used slightly larger diameter U-bolts than Stock, so I had to Torque them down to 100ft-lbs YMMV. You want to Torque these in steps and evenly. I did 30, 50, 75, 90, 100. You want to check the U-bolt Torque after a few miles, and then every couple Hundred Miles until you don't have to tighten them anymore. Your Suspension will move around a little and any play will make these bolts a little loose. They will eventually hold their Torque.

Step 16: You can now re-attach your Brake Lines. You can slide the Hard Lines back in place the same way you removed them earlier. The earlier you re-attach them, the less Fluid will leak.

Step 17: Reinstall the, (new), e-Brakes. The first thing you will want to do here is re-attach the Cable to the Clip. I don't have direct pictures of this, but you can see the "Clip" in question in the picture below on the right. You will want to put Grease were the Shoes contact the Backing Plate, and on the Adjustment Screw. The Springs are a pain to put in Plate, I recommend Locking Pliers. You will want to adjust the Shoes now as it is a lot easier than through the little Grommet on the Rotors.

Step 18: Reattach the ABS Lines. I had to splice the wires on the Driver-side because the Junkyard cut the wires before the plug. You could buy new Sensors, but M226 Sensors are $$$$. Put your Rotors back on, and your Calipers, (Torque to 76 ft-lbs), your Spacers, if applicable and your Wheels.

Step 19: Install the new Shocks. The Top Nut gets Torqued at 33 ft-lbs, and the Bottom at 155 ft-lbs.

Step 20: Fill up your Axle with 2.01L of Gear Oil. I used Mobil 1 75w140

Step 21: Lower the Truck, and Bleed the Brakes.

Now, since the 2wd Axle was a 4-bolt, and the new Axle is a 6-bolt, I had to do the Transmission Modifications at the same time, so I did not install the new Driveshaft yet. See the next section for that...
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Reserved 2
Transmission and Transfer case
Seriously, pretty much everything you do to your Xterra is magical.
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Honestly, with what you're doing, you might as well Titan Swap it. Get a M205 front diff instead of a R180. Most people end up doing that because of the off road advantages and the titan components are stronger. You'll be much happier. Looking forward to this project.
Honestly, with what you're doing, you might as well Titan Swap it. Get a M205 front diff instead of a R180. Most people end up doing that because of the off road advantages and the titan components are stronger. You'll be much happier. Looking forward to this project.
I thought about it, but it's too late now, I already have the R180 and the Suspension. In other news, I got my Transmission Delivered today.

Everything checks out OK. The Fluid Residue when I removed the Torque Converter looked almost as Red as new Fluid.

It does have 2 bolts missing on the back of the Adapter Case, but I can source that fairly easily.

Also, if anybody knows what bolts on the bottom of the Transfer Case Adapter Case, please let me know. It's threaded and didn't have anything there when I received the Unit. I should have taken a more detailed picture, but the hole is circled in Red in the last picture. I was thinking that it's for the Insulator Mount, but I didn't see a second hole. The second one may not be a through hole though ?
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Got the Rear Axle and Rear Driveshaft.

It's Heavy...

Gears look good, Locker works. There is some rust on the housing, but I will clean and paint before installing it. I need to get one of the Springs for the e-Brakes, because one was broken. EDIT: I ordered new Springs and e-Brake Pads. Also, do I need to remove the Axle Shafts to remove the Dust Shields? The right one is rusted through in some spots.
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Following this amazing transformation.
yeah, ya need to pull the axle to remove that dust shield. Slide hammer attached to the lugs & it'll pop right out.
Did some work today.

Cleaned up the Axle and sprayed some Rust Converted on parts of it, also painted the Backing Plates / Dust Shields on both sides. I will put Spare Wheels on it tomorrow and paint the rest of the Axle.

I don't have pictures, but I cleaned up the Slip Yoke on the new Rear Driveshaft, and removed the U-joint. Also started painting the first color of my M226 Cover.

I also decided to reuse my current e-Brake Cables since they're in better shape.

Got my Front Driveshaft. The U-joints had been replaced not too long ago from the looks of it, but I'm still going to change them to be on the safe side + I don't like Grease-able ones.

I should have every part to do the swap now, less a couple bolts I'm waiting on from Nissan.
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Did you already weld on the transfer case mounts? I thought I read somewhere you had to weld some mounts up...
Did you already weld on the transfer case mounts? I thought I read somewhere you had to weld some mounts up...
Edit: Read too quick. You don't need to weld anything for the TC
Did you already weld on the transfer case mounts? I thought I read somewhere you had to weld some mounts up...
I thought that you only had to weld on front diff mounts. Does the rear insulator mount not bolt in?
I thought that you only had to weld on front diff mounts. Does the rear insulator mount not bolt in?
Oops. I read his message too fast. I thought he said front diff :grin:. Pretty sure the TC bolts right in with the new insulator
Oops. I read his message too fast. I thought he said front diff :grin:. Pretty sure the TC bolts right in with the new insulator
Lol okay. That makes sense.
Don't take this the wrong way as it's awesome seeing someone do this but considering how much you've paid for this so far wouldn't it have been easier just to trade in your X for a 4x4 version? You could have stock-ified it and saved a lot of time and probably a decent amount of money.
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Don't take this the wrong way as it's awesome seeing someone do this but considering how much you've paid for this so far wouldn't it have been easier just to trade in your X for a 4x4 version? You could have stock-ified it and saved a lot of time and probably a decent amount of money.
Valid question that I've asked myself many times lol

Cheaper ? yes but not by a lot. If you take out the cost of the fluids / u joints / wheel bearings and Lokka. 3 of which being items that I would have had to change at some point either way.
So from the $3600 to do the swap (the second table is for additional lift only), you'd already drop to $2700. I'm sure 2wd Xterras sell for less than 4wd ones. And I can sell my transmission and axle to get some money back.

Aside from money, I'm not sure it'd actually take less time.. I'd have to swap a lot of stuff from my current X to the new one. Including the suspension.

And it's also a lot more fun >:)
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