PreRunner to 4x4 Conversion Guide

I will do my best to present the parts, process and tools used.
My truck is a 2005 PreRunner Regular Cab.

***Gearing***​

2nd Gen Carrier Differentials come in 4.10 and 3.73

2TR-FE R155 PreRunners run 4.10
2TR-FE R155 5-lug run 3.307 ​

This is mostly a one person job, but a second hand is needed at times.

***Tools***​

Metric socket set
Metric hex set
Transmission Jack
Tie Rod Remover
Torque wrench
Jigsaw

 

***Component Collection***​

http://Car-Part.com​

MAJOR COMPONENTS
R155F [or R156F]
Transfer Case [FJ Cruiser AT]
Carrier Differential [4.10]
Front Driveshaft
Rear Driveshaft





MINOR COMPONENTS
These are the overlooked/associated components that may or may not come with the major components. After you've collected the major components, refer here to get the rest.
You can save a lot of money by requesting the Transfer Case includes the shifter & sensors and the Carrier Differential includes the mounting arms & attaching hardware.
The Transmission and Transfer Case share a breather line, the Carrier Diff has one too.

Carrier Differential [4.10]


Transfer Case [FJ Cruiser AT]


Drive Shaft, Front


Shifter, Transfer Case [FJ Cruiser AT]


Boot [FJ Cruiser MT]


58280-35320 is discontinued, possible to use 58280-04040 from 1st Gen

 

This is completely optional. If you wish to keep A.D.D., harnesses are available HERE or make your own HERE.

***A.D.D. Delete***​

I welded the Sleeve to the Hub, in the engaged position, and sealed the hole with a plate.

1. Unscrew and remove the A.D.D. Module; slide the Sleeve forward, in the "engaged" position, and note the position on the Hub.
2. Removed the Diff Tube by unscrewing the four star bolts.
3. Remove the Snap Ring and slide the Hub and Sleeve off the Shaft and out.
4. Place the Hub within the Sleeve, on a flat surface, and center; tack and weld in the "engaged" position.
5. Slide welded assembly back onto Shaft and reinstall Snap Ring.
6. Position Diff Tube and reinstall four star bolts.
7. Make plate and seal with RTV, Orange FIPG is recommended.

Clutch Sleeve welded to Hub in the "engaged" position- notice they are flush.


Another way, replacing the Tube assembly with one from a FJ Cruiser- $320.
http://www.tacomaworld.com/threads/427258/

 

***Disassembly***​

1. Park on flat ground.
2. Remove all trim between the seats.
3. Unscrew shift knob, remove shift boot and push/twist shifter to remove.
4. Jack and support with jack stands.
5. Unbolt the driveshaft from the 3rd member and slide it out of the R155.
6. Unbolt and move the clutch fork actuator out the way.
7. Unbolt the starter and move out the way.
8. Unbolt the bell housing from the engine.
9. Position and strap the R155 to the jack, supporting the weight.
10. Unbolt transmission mount isolator.
11. Unbolt and remove crossmember.
12. Unplug harness connections as they become visible.
13. Slide R155 out of clutch and lower jack as needed.

This is a GREAT time to change out the clutch and the rear engine seal.

$191 Aisin CKT-065 OE Matched Clutch Kit - Compatible with Select Toyota T100, Tacoma

Aisin CKT-065



It's also a great time to add an Eaton TruTrac LSD

 

You can buy a 4x4 Driveshaft or shorten your current one and replace the slip end with a Flanged Yoke; I shorten mine.

***Rear Driveshaft Shorten***​

When buying mounting hardware for the front driveshaft, buy four additional nuts and washers to mount the rear driveshaft.

Regular Cab
Ø3.5 tube with .083 DOM wall

1330 Series
Flanged Yoke
Spicer 2-2-01904
Tube Shaft
Spicer 2-40-1531
Slip Yoke
Spicer 2-3-8041KX
U-Joint
Spicer 5-1330-1X

Pull 37-1/16" and cut



Weld Tube Shaft on and paint


Access Cab
Ø?? tube with ?? DOM wall

If your driveshaft is a different diameter, you can use the parts above but must find an alternate Tube Shaft; the Tube Shaft must match your tube's diameter/wall and have Ø1.375x16 splines to mate with the Slip Yoke above. Please take a measurement from the same place I did and post here, so we can gather the info for Access Cabs.

This is how you get the cut measurement:

1. Once the R155F is installed, bolt the driveshaft to the 3rd member.
2. Assemble the Spicer components and bolt to the transfer case.
3. With the slip joint at full droop travel (because you're on jack stands), align the driveshaft with the Spicer components and mark where the Tube Shaft's lip meets your driveshaft; this is where you should cut and weld the Tube Shaft on.

Tip:
I don't have a metal chop saw, so to get a square cut I wrapped a piece of paper tightly around the driveshaft and taped the paper end-to-end (circumference of 3.5 is 11); I cut shy of the paper with a band saw and filed to the paper.
I have zero vibrations

 

If you can not tackle this, RST offers a crossmember.

***Crossmember***​

The crossmember on a 4WD is an inch forward, relatively, so the Isolator mount holes must be moved an inch forward.
The R155F's Isolator also sits lower.




Cut, cap with 1/4" plate and weld in, layout/drill 4WD Isolator Mount holes.

***I offset plate 1/4" to driver side so that FJ J-shifter will not rub***​

If you don't have a large enough bit for the center hole, cut around the holes and weld it into the 1/4" plate.
You will still have to layout/drill the four small holes because the 4WD Isolator Mount is different.
12371-0C150 or BECK/ARNLEY 1042029

 

***Shifter***​

Cut the hole for the Transfer Case shifter.

Place the dual boot into position over the existing holes and mark for drilling the rear holes.
When cutting away the upper layer of sheet metal, cut away as little as possible so you don't loose the mount point for the bracket.
If I had to do it again, I'd get a 4" Hole Dozer and drill center of that square (7-1/4" back)

The FJ boot doesn’t just snap in.

1. Give an auto interior shop both boots and have them remove the wire from the FJ boot and sew the Tacoma wire in.
2. Have them transfer the jute of the Tacoma boot over too.

 

***Installation***​

Carrier Differential​

1. Replace seals on each end, where CV axles mate.
2. Install Mount Arms and Rear Mount Bracket onto Carrier Differential.
3. Remove engine pans.
4. Push Carrier Diff Rear Mount Bracket up and onto crossmember.
5. Lift Mount Arms and secure in place with washers and bolts.

Wheel Bearings and CV Axles
​

Remove PreRunner Bearing and Hub Assembly​

1. Remove the tire and wheel assembly.
2. Remove the front brake caliper and hang out of the way. Remove the rotor.
3. Remove the hub grease cap.
4. Remove the hub bolts.
5. Separate the hub from the steering knuckle.
6. Separate the stabilizer link from the steering knuckle.
7. Separate the tie rod end from the steering knuckle.
8. Separate the lower arm from the steering knuckle

Install CV Axle​

1. Install the oil seal at the back of the steering knuckle, where the grease cap was removed.
2. Insert CV axle inboard joint into Carrier Differential, ensuring c-clip is secure in place.
3. Insert CV axle outboard joint through steering knuckle.
4. Reinstall stabilizer link to steering knuckle.
5. Reinstall tie rod end to steering knuckle.
6. Reinstall lower arm to steering knuckle.

Install 4x4 Bearing and Hub Assembly​

1. Install 4x4 Hub to steering knuckle, with Dust Cover between the two.
2. Install hub bolts.
3. Install rotor.
4. Install brake caliper.
5. Install the tire and wheel assembly.
6. Install axle nut and adjust cap.
7. Fill Carrier Diff with oil.

4x4 Wheel Bearing & Hub Assemblies
http://www.tacomaworld.com/threads/537080/​

​

R155F/Transfer Case​

1. Mate the Transfer Case and R155F, using Orange FIPG
   $34 00295-01281 Formed-in-Place Transmission Gasket - 3.5 oz. Tube
   00295-01281 and 90080-11414 bolts (8).
2. Install the breather line.
3. Swap the Speedometer sensor from the transmission with the cover at the rear output of the transfer case.
4. If necessary, transfer the clutch fork and boot; I installed the new throw-out bearing from my clutch kit.
5. If you choose to make one, route the 4WD and 4Lo sensor harness before you install the transmission because there is very little room in the well once installed.
6. Position the R155F/T-case on the transmission jack so that it will not be in the way of the crossmember.
7. Position the R155F/T-case directly behind/below the clutch and raise/slide the assembly forward until it is mated. Connect the harness connections as it becomes possible.
8. Install transmission isolator mount onto R155F.
9. Install crossmember.
10. Install bell housing bolts.
11. Install Starter.
12. Install clutch fork actuator.
13. Install rear driveshaft.
14. Install front driveshaft.
15. Remove jack stands, lower to deck.

Shifters​

1. Before installing Shifters, add oil into the R155F and T-case from the shifter holes.
2. Install R155F Shifter by pressing in and turning.
3. Position the rubber base boot.
4. Install Transfer Case Shifter with large C-clip.
5. Position the rubber base boot.
6. Slide Dual Rubber Boot over the shifters and secure with screws.
7. Reinstall trim between seats, to include new Dual Shifter Boot.
8. Screw on Shift Knobs.
9. Reinstall trim between seats.

 

***4WD and 4Lo Illumination***​

1. Make a connection between the 4WD sensor and 4WD light (C10 Pin 15).
2. Make a connection between the 4Lo sensor and 4Lo light (C10 Pin 16).
3. Ground the second sensor wire.

I accomplished this by making a harness from the sensors to F12 (behind glove box)

 

***Final Thoughts & Links***​

Thanks @awsumdc for your pioneering work with the FJ Transfer Case.

Immediately after starting the truck and driving it around I noticed a coolant leak. Toyota made the Water Bypass Pipe out of PLASTIC on early year 2nd Gens; the moving around of the engine must have cracked this during the install.

Water Bypass Pipe No. 1

16268-75130​

Gasket

16258-75021
​

***Twin Stick Mod***​

The Twin Stick Mod is popular with the FJ T-case for 2Lo.
I would only need 2Lo for backing a trailer. I get 2Lo by shifting into 4Lo, because if I'm on pavement my hubs are unlocked

​

Here is a great write-up by @SMKYTXN

​

***Manual Hubs***
http://www.tacomaworld.com/threads/511528/
​

While researching which parts I needed for the conversion, I realized it was possible to install manual hubs if I had a custom CV outer joint made. After months of research, I had it manufactured; unfortunately no one would make a one-off so I was forced into ordering dozens. After a successful trial, I now offer this as a kit. Folks doing a 4x4 conversion have the most value to gain from this kit because you have to buy new bearings/hubs and CV axles anyway, and it affords you the choice to delete the failure prone A.D.D. Actuator.

 

Very interesting looking forward to the final product. When you get a chance could you go deeper into the manual hub conversion

 

Great write up and love those shifters, everything looks super clean

 

Awesome! Wish I had the guts to attempt this on my 2012. Haha

 

It’s really not too bad, it’s plug and play for the majority of it. The only time I was nervous was when cutting the hole for the shifter, but only because I had to trust my own measurements lol; the drawing above is what I WISH I had done.
The two hurdles for me were the driveshaft and crossmember. A guy told me RST now sells the crossmember. I would have got the rear driveshaft off of car-part.com if I had know of it then.

 

just awesome

 

Well done..!

 

Great work. I really want to do this on my 2004. I cant get myself to do it yet.

Sourcing all the right parts seems like the hardest part.

 

Nice Job man!!

 

Thanks brah

 

I'm going to have to re read this thread soon, thanks for the write up!