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Building 4wd 620. How difficult?


What can/should I do to get 4wd?  

5 members have voted

  1. 1. What can/should I do to get 4wd?

    • Balljoint method w/ aftermarket lift
      0
    • Custom solid-axle front end
      10
    • Front-clip or full-frame swap
      3
    • You're nuts, not worth it.
      3


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Hi everyone,

 

I'm interested in converting my '75 reg cab 620 to 4wd.

 

I was wondering if anyone was aware how similar 2wd and 4wd Nissan Hardbody frames were. What I'm getting at is that I was thinking I could do a balljoint conversion using 4wd nissan parts rather than 2wd and get a local offroad shop to do the fabrication for the front diff and transfer case mounting. I would also use an aftermarket nissan lift kit for the front and get custom leafs to lift the rear and put a generic 3" body lift on.

 

Does anyone know if this is possible? I'd assume if the only difference between 2wd and 4wd Nissans is in the suspension and not the frame mounts, then the 4wd suspension would bolt up just the same as a typical 2wd balljoint conversion with a custom upper arm.

 

Option 2 is going with a solid axle front end, a pretty standard custom job for most fab shops specializing in 4x4s. Much more lift is also possible with this option, maybe too much :D

 

Other options include front-clip or full frame swaps from 4x4 vehicles, but I'd rather not go this route due to increased cost and complexity, and the need for a donor vehicle

 

I would much prefer to go the balljoint way and keep the IFS for its sheer simplicity and relative low cost (and to keep the nissan blood). Otherwise I'd probably go solid axle.

 

What are your opinions on these various methods? Or am I just crazy?

 

Thanks guys.

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You have a '75, the D21 is two generations removed from your 620. Not good.

 

The 720 and D21 4X4 body mounts sit a few inches higher on the frame than the 2wd. From '83 on the 720 and D21, 2wd and 4wd LCAs are totally different. 2wd uses tension rods the 4wd do not. Torsion bars are not interchangeable between 2 and 4 wheel. The transfer case front and rear drive shafts will not clear a 2wd cross frames. The list is endless...

 

Converting a king pin 620 to IFS is... well I'll sugar coat it a bit... it's a crazy amount of work. If you absolutely have to have a 720 or D21 IFS 4X4, buy one and put your '75 body on it. If you decide on a 720 you can swap in your motor and tranny, so find one that has a pooooched motor and is cheap but runs good. If you choose a D21 forget your motor and go with the KA or VG that's in it.

Edited by datzenmike
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if you want to do it on the cheap, get a jeep wrangler dana 35, you can score these for less than 100 bucks try to get the stock leaf springs and go spring over, get a suzuki divorsed t-case also less than 100 bucks, and do the fab work yourself. You will need to have some custom drive shafts made and you are good to wheel. the stock suzuki t case can handle a lot of abuse from a built four cylinder engine.

 

we are getting ready to do this swap on my neighbors 76 620 which he already off road's on one wheel drive. a lot of jeep guys

 

if you are planning crazy lift and over 35 inch tires, then the waggy front diff which is a dana 44, is the ticket. but if your plan is to keep the lift moderate and tires under 35, and you are going to stick with your L20b engine, the jeep dana 35 will survive. The yota axle is good compromise between the dana 35 and dana 44, but finding one complete will set you back at the least 250 or more. factor in also that whatever solid front axle you get will have to get the gears changed to match the front.

Edited by b210in
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Too bad the dana 35 won't handle a lot of abuse from a built four cylinder engine. The stock rear in that 620 is prolly 3 to 4 times stronger than a 35. Why downgrade? I'd be looking for a Ford 8.8 out of an exploder if you wanna run that 5 on 4.5 lug pattern. and keep the YJ/TJ width.

 

Of course, I'd be looking to keep the 6-lug pattern and in my neck of the woods, waggy axles are alot easier to find than wrangler axles...added benefit is they are about as strong as the stock H190.

 

If you wanna be cheap that's cool, but installing weaker parts is weak...

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low datsun, we can help you more if you can establish what the intended use of the 620 is going to be. do you want a full on wheeling machine? or more of a cruiser 4x4 that occasionally sees some wheeling.

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+1 on what redeye said. my friend also built one using dodge powerwagon axles. it may not look the greatest but that truck is unstoppable in any terrain.

 

Are you kidding, that thing does look the greatest. Love it.

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Thanks for the tips guys.

 

To clarify, this project is going to be used for getting as deep into the backcountry as possible with a road-capable vehicle. I live in British Columbia, Canada, so that means primarily mountainous forests and river crossings, but it will be used for travel as well.

 

The plan is to build a supremely agile trail-rig, as a base for outdoor adventure including mountain-biking, kayaking, hiking, and just plain camping.

 

I know there are far better, far more aftermarket supported vehicles out there that would be cheaper/easier to get parts to fit this niche, but I have the Datsun, and love it to death. It's anything but common, and undeniably the sexiest pre-mid-90s mini-truck made. It's small enough for tight trails, and big enough to meet my needs. I'd hate to build it with anything else.

 

I think I'm going to go with the SAS for many reasons, but mainly it's probably easiest to find a shop to do the work, and its pretty straight forward, and the most versatile off-road.

 

The next question is leaf's or 4-links with coil-overs. Leafs would obviously be cheaper and easier to source, with less fab work, but coil-overs, well, no justification necessary, except that price tag...

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  • 3 weeks later...
2eDeYe;150135']Too bad the dana 35 won't handle a lot of abuse from a built four cylinder engine. The stock rear in that 620 is prolly 3 to 4 times stronger than a 35. Why downgrade? I'd be looking for a Ford 8.8 out of an exploder if you wanna run that 5 on 4.5 lug pattern. and keep the YJ/TJ width.

 

Of course' date=' I'd be looking to keep the 6-lug pattern and in my neck of the woods, waggy axles are alot easier to find than wrangler axles...added benefit is they are about as strong as the stock H190.

 

If you wanna be cheap that's cool, but installing weaker parts is weak...[/quote']

 

you betcha!! i changed out the pos chrys 8.25 in my cherokee(yes i know not a d35 but they both suck) with an 8.8 and did the same with my buddys cj and it rocks!! yeah not 6-5.5 bolt pattern but worth the cheap strength

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  • 7 years later...

If I could jump in with a question of my own. Is the 78' 620 considered a kingpin having the discs upfront. And if kingpin could be explained

 

 

 

Disc brake has ball joints and is not a kingpin truck. 

 

Kingpin is just like it sounds 1 pin that is held by the axle and the spindle is connected to the pin at the top and bottom and pivots. It's one of the oldest steering joint designs there is. 

 

Kingpin

 

king011.JPG

 

 

Ball joint.

 

DSCN0616.jpg

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