84 Nissan Dually conversion?

[Berkybot]

I own an 84 720 4x4 with the z24 engine. Would it be possible to turn this into a dually? From what I understand Nissan made a c200 dually axle, if I can find one would I be able to put it on my truck? And also if this is possible would the z24 even be able to efficiently turn two more tires.

[Stoffregen Motorsports]

If you can find the axle, it should bolt in with not much hassle. You may want to also grab the front hubs and wheels so they match.

 

Dually on any truck does cut down on efficiency. I think it has more to do with the air you're pushing than the extra tires on the ground. At one time, I had a '97 Suburban with a big block and 4 wheel drive. It got around 15 mpg. At the same time, I also had a '98 K3500 dually with the same motor (albeit different R&P) and it got 9-10 mpg. Same motor and trans.

[datzenmike]

The dually WAS available as an option on the HD heavy duty or Cab Chassis truck and used on the '83 and up 720 with the Z24 engine. The Cab Chassis option had no box and it was assumed that a custom utility box, flat bed or camper would be installed. Four tires are no harder to turn than two. They can just carry more weight and for this a 4.375 ratio differential was used.

 

Stock 720s carried 500Kg or 1,100 pound

Heavy Duty carried 700Kg or 1,540 pounds*

Heavy Duty (dual tires) carried 770Kg or 1,700 pounds.*

 

* Almost certainly the Heavy Duty used stiffer leaf springs and E78 x 14 tires. 

 

My information says the 2wd HD used an H-190 differential. edit:The HD dual wheel and the 4x4 used the C-200. The HD also used a special wheel bearing not used on the regular 2wd. Wayno would know much more than this. He's dealt with dual tires 

[Crashtd420]

12 minutes ago, datzenmike said:

The dually WAS available as an option on the HD heavy duty or Cab Chassis truck and used on the '83 and up 720 with the Z24 engine. The Cab Chassis option had no box and it was assumed that a custom utility box, flat bed or camper would be installed. Four tires are no harder to turn than two. They can just carry more weight and for this a 4.375 ratio differential was used.

 

Stock 720s carried 500Kg or 1,100 pound

Heavy Duty carried 700Kg or 1,540 pounds*

Heavy Duty (dual tires) carried 770Kg or 1,700 pounds.*

 

* Almost certainly the Heavy Duty used stiffer leaf springs and E78 x 14 tires. 

 

My information says the 2wd HD used an H-190 differential and only the 4x4 used the C-200. The HD also used a special wheel bearing not used on the regular 2wd. Wayno would know much more than this. He's dealt with dual tires 

So could he simply run dually rims?

 

Berkybot are you after a look or more load capacity?

[datzenmike]

Dual tires won't clear the box. I think the rims are also different. This is the guy to contact about any questions... https://ratsun.net/profile/5657-wayno/

[Thomas Perkins]

If you look in your FSM Manual.Mine is a 85 one.Look at section PD-75.It has a listing of differential Carriers..It states that the Z24 engine.Double tire and 4WD are both C200.I remember seeing this when I put a new seal in mine.They all use the same seal.

[The Newt]

I have a 1980 2WD dually. I’m brand new to this so I’m still trying to figure this site out. I’d post a picture but I can’t seem to figure out how. 

Edited August 2, 2023 by The Newt
Had more info

[datzenmike]

2 hours ago, Thomas Perkins said:

If you look in your FSM Manual.Mine is a 85 one.Look at section PD-75.It has a listing of differential Carriers..It states that the Z24 engine.Double tire and 4WD are both C200.I remember seeing this when I put a new seal in mine.They all use the same seal.

 

The '83 and up HD single wheel is an H-190. It shows the dual wheel HD also H-190 but the graph shows C-200. Must be a miss print. That does make sense so we'll go with it.

 

Now, if I can just remember this next time.

[wayno]

I have done quite a bit with the dually axle and dually rims, yes the dually axle and later 4wd axle are C200 axles, the carrier is interchangeable, but the axles are different, the dually axle is a floating axle with 2 bears on each side while the 4wd axle has only one bearing I believe, also the pinion flange on the 4wd axle is much larger than what comes on the dually axle, as I recall I used the dually axle pinion flange on the 4wd carrier when I lost the carrier in my dually axle.

 

The dually axle came in 3 different gear ratios(4.88/4.62/4.37), 4 different ratios if you put the 4.1 4wd ratio into the dually axle, I have the 4.62 ratio under my 1971 Datsun 521 work truck right now and like it the best, I had the 4.37 gears under it a while back and it was hard getting the 6000lb rolling weight moving(truck/trailer) when I had another ton of wet moss in the bed.

 

I also have an adapter to put dually rims on an H190 axle, my 1980 720 diesel used this adapter as it had 3.30 gears, it is great but not made to haul weight, also aftermarket dually rims can be bought for the H190 axle, there are also old school adapters that use stock 620 rims to make you truck into a dually, but you need small truck dually fenders.

 

I have about 4+ different ways to make a dually out of a stock truck, the easiest is using aftermarket dually rims(6 lug rims), I do not have photos on my laptop of all my versions, I have extra dually axles, and extra adapters, I even have a set of 13" dually rims/adapters, it is crazy what one can collect when motivated.

 

In the photo below you can see the 521 dually and the 1980 720 dually with a flatbed on it and the stock box with dually fenders in front of it.