How to Convert a 1985 Nissan 720 2wd to 4 wheel drive. 

I used only Nissan parts. 100% bolt on, no drilling, no welding. (Except for cutting a Shifter hole).

 The 720 truck is the first factory 4wd Nissan. 1980 to 1986. Reg cab, King Cab, Long Bed and Double Cab (Not sold in the US until D22 model). Prior to 1980 Nissan dealers had 3rd party company's convert new 620s (1972.5 to 1979) to 4wd and sold them as NEW 4wd trucks. For example Low Manufacturing now known as Spencer Low Racing.

Story: I wanted to lift my 85 2wd King Cab higher. I already had a 3inch suspension lift and a 2inch body lift with 30inch tires. The King Cab was now about the height of a stock 4wd. So I decided to just buy a used 4wd frame and swap everything over. I called a local Nissan Junk Yard and inquired about prices. The Junk Yard just received a drivable rolled 85 King Cab yesterday, already pulled motor, trans, radiator and tailgate. The body was destroyed. I bought the rolled 85 truck complete minus engine and trans and above items. I had it towed to a friends driveway. I stripped the cab and bed off the rolled truck. Minutes later a guy came buy looking for scrap metal and hauled the cab and bed away free. He did not speak English but the 2 of us threw the parts (old cab and bed) in his pickup and they where gone. That was easy. Now for the details. 2 weeks later is was done. I did not reinstall 2"BL due to cosmetics. I did buy another 2Inch triple shock UCA lift from Jim Conner. The last kit sold before he retired. 

This is the stripped done 4wd rolling chassis. I used everything shown except for rims and tires. My 2wd 5inch lifted 720 KC is behind. Click on picture for a closer look. You can see thrashed cab and bed on right side. 

The parts that are different THAT YOU NEED are as follows:

  • 3 of the 5 exhaust pieces. The muffler, manifold and cat are the same.

  • Oil pan and oil pickup tube.

  • Lower steering linkage, between box and ujoint.

  • 4 wd Transmission,  see note 5.

  • Gas tank, 4wd is bigger, might be able to use 2wd in a 4wd frame.

  • 4wd indicator light harness and indicator plastic piece for dash.

  • All suspension pieces front and rear.

  • All driveline pieces.

  • Front brake lines to calipers. see note 3

  • Clutch slave cylinder. see note 6. Funny

Tools needed: Engine hoist for Cab and engine. Basic sockets and wrenches all metric. 10, 12, 14, 17, 19mm. And Phillips screw drivers. Sawzall or jigsaw for hole cutting.

  1. Remove old cab from 4wd frame

  2. Remove old bed from 4wd frame.

  3. Remove 4wd shifter from Transfer case if not already off.

  4. Frame should only have the following systems in place. Gas tank, transfer case, suspension and exhaust system minus collector pipe.

  5. Bolt good cab onto 4wd frame. There are 4 big bolts on a King cab at the corners, and 2 smaller ones under the floor mats. There is a weird rubber mount.

  6. Connect clutch and brake lines and bleed, I used my 2wd calipers and drums.

  7. Bolt bed onto 4wd frame. 6 or 8 bolts,

  8. Connect filler neck to bed.

  9. Transfer engine onto 4wd frame.

  10. Connect all engine wires and hoses.

  11. Transfer trans onto 4wd frame. see note 5.

  12. Connect reverse light, neutral light and clutch line.

  13. Connect drive shaft to transfer case.

  14. Transfer bumpers, radiator and tires onto 4wd frame

  15. Cut a huge hole in floor for shifter. This is the hardest part. I used a lot of aftermarket boots, before I ended up buying a stock Nissan boot. The most expensive Hurst boot only lasted one year. The hole is long and skinny kind of like the goodyear blimp shape.

  16. Un bolt the lower section of the 4x4 steering column at in the cab. The lower sections are different (2wd or 4wd). This is very easy, 4 bolts in 5 minutes.

  17. The 4wd wiring harness will plug right into the main harness under the passenger seat. This is for the 4x4 indicator light and fuel pump.

I think that was it. I did this with basic hand tools in a friends driveway in 1994 in about 2 weeks. 

Note 1: I did not reinstall the 2 inch body lift. I did buy another UCA lift kit and install 32x11 Bridgestone Duelers and 4,88 gears.

Note 2 : All 720 2wds have Chrome trim and 4wds have black trim. This changed in 86.5 with the D21.

Note 3: Brakes are the same on 2wd and 4wd. Calipers, drums etc.

Note 4: 2wd came with 14inch rims and 4wd came with 15inch rims. All Nissan Trucks have the same 6 lug.

Note 5: 2wd have a longer trans, and 4wd have a short more rare and expensive. I had my drive shaft professionally shortened because I had a good 2wd trans. It is a little harder to get in though.

Note 6:  My 2wd slave cylinder hit the 4wd oil pan. But my buddies 280zx had the type of slave I needed. I traded my 2wd one for the Z one. The Z has plenty of clearance for either style. I did the conversion in his driveway.

Note 7: My only regret is that I did not take allot of pictures, I have some. I need to find and scan.