Hello, I've heard people talk about turning a 2wd truck into a 4x4 before and I know it's expensive and pretty difficult... I'd like to put a tranfer case in a 2wd truck for the low range only (not to convert it to 4wd), so I can have a 2wd Lo ratio for mild wheelin'. Would I have to find a GM t-case for a GM truck or a Ford for a Ford? I heard a little about divorced t-cases... I figured it'd be not too difficult to bolt a t-case to a tranny that's also used on 4x4's and all I'd have to do is get a brace to hold the t-case, shorten or buy a different driveshaft and have some way of shifting it. Would it be hard or expensive to put a t-case shifter or switch for a "shift-on-the-fly" model in a 2wd? I've heard a complete 4x4 conversion usually costs around $3000, how much do y'all think this would cost since I won't need any parts forward of the t-case?  

There are a few types of under drives u can buy.  I think one is klune V i doubt thats spelt right.  

Aren't all the other underdrive kits for bolting on to an existing t-case, not a tranny?  

Hey pwrwgn! I forgot to mention something else; I looked up info on Atlas, Klune V and other companies looking for an underdrive and I even emailed  one of them about if their underdrives would work on a 2wd and got no response. So that's why I'd like to put a t-case in a 2wd truck. Do you know any underdrives that'd work without needing a t-case?  

Well i dont think any of them need a transfer case. I THINK they all mount to the tranny but, Really i am not shure about it because i never thought of puting one in to a 2 wheeler.  

i don't think you're gonna find an underdrive that will work like that. the klune v mounts between the tranny and t-case. i think the cheapest bet would be finding a cheap t-case and mouning it divorced from the tranny.  

Hey valleycat! That's what I was figuring. In 4wheel&Offroad's tech articles on building a 2wd for offroad, they said it's main disadvantage is without a gear reduction like a low range in a t-case a 2wd will have to "fly" over terrain instead of crawl. They also said that's the main reason someone with a 2wd should consider a long travel kit since objects will be (generally speaking) at higher speeds. How much would a divorced t-case, shift linkage or controls and a shorter/shortened driveshaft cost roughly? I do think high-boy/prerunner trucks are cool, but I like to be different. Plus I think it could be cheaper to swap in a t-case instead of a 3.5" lift kit from Fabtech. I also like the idea that parked the truck would look like a boring stock 2wd truck. (car thieves?)

Would it be easy to install a divorced t-case, shorter driveshaft and t-case shifter or control switch? Would I need to find or make a brace/crossmember to support the t-case? Any help appreciated! Thanks.

Since you didn'tmention what kind of 2WD truck you have, I'll just throw a few more things youmight want to think about:

1. A divorced T-case will be longer and require a third very short driveshaft between your 2WD tranny and the t case. No one has used divorced tcases in a while, (Dodge and ford quit many years ago and lil Samuris were that last I think) so one that fits the bill might be more difficult to find.

2. Try to find the stuff you need from the same model 4WD so you can see what the factory offered, take advantage of what the engineers figured out for you already.

3. Often the front suspension, steering box, and even crossmembers and frame are different on a 2WD v/s 4WD model.

4. Gear Vendors offers an overdrive OR underdrive unit  (one or the other but not both in the same gearbox) that attaches to the back of your tranny. Their more popular item is the overdrive unit though only good for 2WDm but great if you swap in super low axle gears and still want to drive on the highway. But it costs about as much as a transmission! 

5. Unless you have a serious emotional atttachement to the present vehicle, or you just have a bunch of time and money layin' around, you'd be better off to sell it and buy a factory 4WD.

6. 2WD to 4WD is not impossible to do, but more involved than just adding a front axle and tcase.

Hey guidolyons! Let's say I had a 88-98 GM. If I wanted a t-cased 2wd truck would I have to take out a 88-98 GM's tranny, t-case and a crossmember and shorter driveshaft to make it work?

(I know it's a hassle, but seriously, it seems really dumb that there are companies who make extra gear reduction devices like an Atlas 4:1 crawler for 4x4's who already usually have a 4wd Lo that's below 2:1 and the most I've heard compatible with a 2wd is something like a 1.3:1 underdrive; I'm trying to avoid buying a 4x4 for increased insurance premiums only. By buying a truck with 4x4, it'll probably take a thousand dollars or more away from me a year for insurance, partly 'cause in only 23 years old)

Ya gata pay to play, i dont think 4x4 makes that much difrence ive had 4x4s sence i started driving. Just get a job and pay up if its really thatmuch more. Or shoparound for a better inshurance company it pays to compare.  

Man i'm 23 and it costs me less to insure my $10,000 92 k1500 than it does my $600 94 3cyl Geo metro. My truck costs $68 a month for full coverage and my car costs $89 a month for basic liability. Go figure.

Change insurance companies. most companies i know of DO NOT penalize clients for owning a 4x4.

I hardly ever use 4Lo, cus 4hi pulls me out. When i get stuck, its a lack of traction, not gear reduction. I'll put it this way, If you get stuck in 2hi, your "2Lo" wont get out.

I'm all for people building 2wd trucks, but this t-case for gear reduction seems crazy. Get a good lift with lots of travel, some 33" tires, slap in some 4.10's and a detroit locker in your axle, and have fun!

Wow Quyonmob! Those insurance comparisons are amazing! If I don't have to pay a few hundred bucks more annually for a 4x4 I reckon I might want one instead. I've driven in snow with different vehicles and it seemed easier to get unstuck or keep from getting stuck with a steeper first gear in an automatic 'cause the wheel speed is slow. Do you live way out in the country? Insurance is the main reason I don't have a vehicle. Any man under 25 and not married should expect to pay over $3000 per year for even a cheap vehicle! (girls under 25 can pay under a grand!)

You're 23 and own two vehicles! You must have a real sweet job. Most people my age here would be lucky to get more than $11/hour and average rent here is about $450 a month for a reasonable apartment.

I live in ottawa, ontario, canada. Yeah, i live in the stix, but my vehicles are registered to the city of ottawa.

Sweet job? yes, but not dollar figure wise. I am currently a bear technician with the ministry of natural resources. I work seasonal contracts. Just gotta keeps tabs on the cash flow in and out.

Good luck with finding better insurace man.

most of the 80`s ford 4 speeds i come across have a granny first.i know what you mean about taking off on snowpack and ice.it`s not easy with tall geared manual trans.i have 3.45`s and a 5 speed in my ranger.  

gear reduction does play a very important role..it's not necessarily a traction issue... it's a power vs. traction issue... to hit peak power with your vehicle and high gears you have to have wheel speed... to hit peak power with what's known as a granny gear all you have to do is let out on the clutch... the engine is under less stress so it can work at lower rpms without stalling... so you can work at maintaining traction without having to give it the gas and keeping up power...  when you're tires are already spinning at 30 mph they can't regain any traction on a slick surface... and there are things called "brownie box's" it's basically a 2 speed tranny that trucks put behind the transmission to give them an extra gear... they work especially well with a manual transmission.

http://truckpartssa.com/overUnder/index.html