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-   -   S10 4x4 Conversion? ( 12-09-2003 09:18 PM

S10 4x4 Conversion?
Hi, This weekend it snow pretty bad and I was feelin blue because my friends were out having fun in there 4x4 beasts while i loaded sandbags and snow into the back of my truck. :sweat: Then it hit me then, if I'm going to go through the trouble of a V8 conversion, why not slap on a transfer case and get live front axle? What do you guys think? I have serious doubts it will work as simply as i put it, but I'm willing to put in the extra effort.

I was able to find that s10 trucks have np231's behind their NV3500's, but i also found that 4x2 manual trannys weren't the quite the same as the 4x4 manual trannys. I just don't know what though, will the np231 bolt to any NV3500, regardless of its origins? Thanks for entertaining this 5-minute whim of mine:D

1991 GMC Sonoma 2WD Extended Cab w/ 4.3 TBI

astroracer 12-10-2003 05:08 AM

I'd just sell the truck and get a 4WD... Swap your small block into that one.. A whole lot simpler and cheaper... :thumbup:

M&M CUSTOM 12-10-2003 02:38 PM

It CAN be done but you will definitely NOT like the price and hassle of trying to get things right even if you do all the work yourself. Using stock parts.
The easiest way to go 4WD on your truck would go with an older solid Toyota solid front axle and leaf springs, then choose the transfer case from there, still a lot of fabrication, as after the front is done you will have to lift the rear to match it.
Your best bet would be to go with a truck already equipped with 4WD and do your desired swaps and upgrades from there.

Ohio-Dan 12-10-2003 09:12 PM

The NV3500 has a two piece case that splits into a front and back half. To convert a 2WD NV3500 to 4X4, you need to change the rear half of the case and the output shaft.

Easier to find a 4X4 trans to start with.

The NP231C is the stock case that comes with a 4.3 S-10. Get an 89' and up with the electric speedo hook up.

The easiest 4X4 conversion would use a Jeep reverse cut, high pinion Dana 30 front axle. I would use a Cherokee axle because it is cheaper and easier to find. You have to weld on spring perches as the Cherokee used coil springs up front. A TJ or YJ has leaf springs but they are harder to find.

Mount the axle with a hand made cross member and rear leaf springs from a full size Chevy half ton truck. I have drawings of the cross member if you would like to see them. Shackles mount to the frame on the rear part of the springs.

Use stock steering parts from the Cherokee as well. The pitman arm will bolt to the stock S-10 steering box, and give you a 4" drop pitman arm. Lift will be in the 4"-5" range over all. 5" will clear a 33-12.50.

The rear end lift is as simple as a spring over conversion. Cut the spring perches off and weld them on top. Bolt it back together with the axle under the springs. When you get the donor front axle, get the rear as well. It will save the hassle of gear ratio and different wheel bolt pattern woes.

Over all, the conversion isn't as hard as most think. There is, still quite a bit to it though. Little things like drive shaft length and shocks to work out. The Jeep used a NP231 so the switch to run the CAD front axle will screw right into the S-10 case. A drive shaft safety loop welded into the trans cross member will allow the front drive shaft to pass threw. You don't need an expensive conversion oil pan like you do with a conventional S-10 4X4 V-8 swap. You can also use the cheap Headman 2WD headers that won't fit a 4X4 chassis because of interference with shock mounts. Dan 12-18-2003 03:03 PM

Could I use a divorced transfer case like a NP205? Would that be more work than modifying my transmission to accept a NP231? I like the idea of a SOA conversion, didn't think about that! Quick question, when you refered to the Cherokee front axle, what does CAD stand for?

Ohio-Dan 12-18-2003 08:51 PM

Central Axle Disconnect, The vacuum operated mechanism that locks and unlocks the front axle. A S-10 uses a diaphragm on the fender well connected by a cable to the front diff. The Jeep mounts the diaphragm on the axle itself. The vacuum diaphragm is controlled by a switch on the transfer case. The Jeep uses a 4 line switch and the S-10 uses a 3 line. The Jeep axle uses vacuum to disengage the axle where the S-10 uses spring pressure.

A 205 would be extreme overkill for what you want to do.They are a big, heavy, gear drive case that is near indestructible. They also only have a poor 1.96 low range ratio. If your plans where to run a 500+ inch big block and 44's, the 205 is for you. For your small block truck, I think the custom cross member and mounts, another drive shaft, plus the added cost of the larger t-case would be allot more work and money in the long run.

Where do you live? Anywhere near Ohio? I have a NV3500 and NP231C that I could sell or swap if you are close. I think I still have a D30/D35C axle set out back as well. The D35 is sort of weak but it will give you a matched gear set until you find a better axle. A Ford Explorer 8.8" with disc brakes would be a good choice. Same lug pattern and all......

I'll try and post some pics in my album later this evening so you can get an idea of what you are looking at. Dan

11secmudtrk 12-19-2003 05:31 AM

Use a TH400 and jeep Dana 20, front axle should be simple enough, just be sure to get all brackets off donor vehicle. 12-19-2003 12:55 PM

Thanks for the offer dan, but I live in Rhode Island. I mentioned the NP205 because that was the only divorced t-case i could think of. (Side note: whats wrong with overkill? ;) )

Do you know of any lighter divorced t-cases? I think a divorced t-case is the route I would go because I'd rather get some weight towards the back and fab'n mounts aren't a big deal.

Sorry for the dumb questions, i'm new to this kinda thing, but i believe i can do this will a little guidance. Thanks!

11secmudtrk 12-20-2003 07:33 AM

A divorced dana 20 can be found in older IH trucks, but I would run a TH400 non-divored 20 because of the short wheelbase.:pimp:

Ohio-Dan 12-20-2003 10:24 AM


(Side note: whats wrong with overkill?)
If you use a gear box that is bigger than what you need, you are wasting horsepower. The larger gears take more power to turn because they are heavier and have more friction. You also carry the weight penalty of the larger box that causes a decrease in performance as well. As with any build, the idea is to get as much power to the ground, in as light a package as you can.

A TH400 is overkill for a small block making the high 200 to low 300 horsepower numbers you said you where shooting for. The TH400 also doesn't have overdrive. Fuel mileage would suffer. I gather that you want to keep the stick trans you already have in hopes of saving the money on a new trans purchase. Nothing wrong with that.

Your choices on a divorced case is limited. The Ford 205 may be the only one with a left side drop. I think the IH case is right side and so is the Suzuki case used in the Samurai. Strength will become an issue with the Samurai case. I have seen them hold a 4.3/200-4R combo, but don't know how much more they will take. I think there is an after market kit to divorce a Toyota case? With all of these, your electric speedo would need adapted.

I still think a married 231 would be the best choice.

The only wheel base issues you will have is front drive shaft angle. Your wheel base should be about 123"(That's not "short"). You don't need or even want a short trans/case combo. Your extended cab gives you allot of room to get things moved back to help with front shaft angle issues. The use of a reverse cut front axle helps the front drive shaft angle because the pinion enters the axle higher.

An after market kit to divorce a Toyota case and Toyota front axle might be an option like M&M suggested..........I don't know what you'll get into with steering and such. Cost may be an issue as well. The D30 swap works well because it bolts up easy and the Jeep used a 231 like the S-10, and there are no major issues with steering hook up. Dan

11secmudtrk 12-20-2003 08:05 PM

Nothing wrong with overkill, the difference in power and weight won't be noticed unless your racing, even then it shouldn't be much of a problem. I wouldn't guess fuel milliage is much concern if the guy is swapping a v8 in. A NP231 would be a decent choice as long as it isn't a slip yoke unit. I'm pretty sure the divorced toyota case you speak of is found in older land cruisers..:pimp:

Samo 02-17-2004 10:36 AM


I am doing a similar swap on my 94 sonoma 5.7L, a dana 44 out of a Jeep wagoneer is a great doner. The dana 44 is strong enough to handle whatever your 350 can dish out and tires up to 35". Many parts are also available to make it even stronger. The Jeep dana 44 is also a great width to use under the S10 and the diff is on the drivers side making it match up with the transfer case well. It will have a leaf spring setup and disc brakes. I found mine on an 83 wagoneer, bought the whole truck for $300 and took both axles (AMC 20 rear). I am swapping in both axles so I will have the same width axles/gear ratios/6 bolt lugs all the way around. The front driveshaft was also a double cardigan type (meaning it has a dual U joint on the front) and the front axle already has a steering stabilizer from the factory.


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