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How do I convert my two wheel drive Wagon into four wheel drive?


How do you convert 2wd to 4wd? The following is not a smart mouth reply: Jack-up your Wagon's body and roll in a new 4wd frame and running gear.

Why? Here's some of the reasons for not attempting the conversion:

  1. The frames and suspension are different. Two wheel drive Wagons have Planar (transverse leaf) front suspension, while the 4wd versions have conventional leaf springs. That's alot of hacking and hewing to change things.
  2. The 2wd frames may be significantly weaker than their 4wd counterparts.
  3. You'll need a front end with the same ratio as the rear end.
  4. You'll need a front drive shaft and and you'll need to shorten the rear shaft.
  5. You'll need to pay close attention to steering geometry,
  6. There's about a hundred other issues to boot.
All of this spells lots of $$ and time. The bottom line is that a conversion cwould cost more and take more time than a full chassis replacement. But, don't despair!

The fundamental question here is: How good is your Wagon's body? If it's largely straight and free of body rot, then you are in business. B-U-T, if it''s a complete original 2wd in very good condition, it's probably gonna be worth alot more than a somewhat cruddy 4wd Wagon (Note also that many Willysnuts, including yours truly, would be incensed if you hacked up a pristine original). So there you are. You've got some decision making to do.

Because so many Willysnuts are opting for Blazer and other running gear, if you show patience, you ought to be able to pick up the stock running gear for a song. I've even seen ads offering this stuff for free (no doubt because the wife is tired of staring at it). If you're going to be doing heavy duty off roading, why not select a relatively modern donor vehicle and plop your Wagon body on it?


How do I adapt my high performance V-8 to a Jeep T-90 transmission?
This question pops-up online seemingly every day. The straight answer is: while there is an adapter made to graft just about any sort of bell housing to a T-90, DON'T! In the words of Wagon guru Paul Berry:

...repowered doesn't mean dropping a small block V-8 motor with an adapter plate & bolting it to the original running gear. You must change everything. Remember that the transmission and axles were originally designed for a 63hp flat head four not a 200hp V-8 with an increased torque band.

My own two cents: In 1970, I bought my second CJ, a '61 Tuxedo Park which I immediately tore into, plopping a 327 Chevy ahead of the T-90. This was my first conversion, and even though I didn't know a heck of alot about automotive science, the project was a fairly easy - but still time consuming. After assembly, I used the Jeep a a daily driver, but off-roaded sparingly and timidly. I never broke the wheels free on dry pavement, either. One day, after about six months of this, I down-shifted from third to second on a freeway cloverleaf, and BAM! The cluster gear was gone.

So, forget the T-90. I had better luck with my next conversion, a 327 + Muncie four speed into a '51 CJ3a with a stock transfer case. It never gave way, but again my off roading was rare and gentle. You'd be best off replacing that Dana Model 18 transfer case with a later Model 20 out of a Wagoneer, but when you figure in the cost of a tranny-to-transfer-case adapter, it would probably be cheaper (and certainly easier) to go with an entire engine-trannny-t,c. assembly out of a Blazer. Then, you still have undersized drive shafts and axles...

I'd recommend that you get a copy of the Willys-America catalog. Paul Berry lays out your re-power options very thoroghly. Otherwise, your best bet is to do a full frame and running gear swap, or live with what you've got. A Wagon with the original six and overdrive will get you around very nicely.