Top Jeep Transfer Case Swaps

It doesn't matter if you are hung up on a chain-driven case or want a gear-only, cast-iron splitter. We've all toyed with the idea of swapping the stock transfer case. Face it, most stock Jeep units leave something to be desired.

1. NP205
Plus: Pretty cheap to come by, brutally strong, cast-iron case and all-gear internals, and the ability to be twin-sticked.

Minus: Heavy and a limited 1.96:1 low range means it's probably not for a rockcrawler unless you've got a granny-low First gear or a doubler.

Use it if: You've got a high-horse motor, really heavy rig, and don't care about going out in rocks.

2. NP241OR
Plus: 4:1 low range, wider and stronger chain than the NP231, will bolt up to many '87-and-later Jeep transmissions, and no slip yoke.

Minus: 4:1 might be too low for some applications, the thin case means that even a healthy small-block will be pushing the limits of this case (even with the wider chain), electronic speedometer pickup, and it can't be twin-sticked.

Use it if: All you plan on doing is crawling or you've got an engine that can handle the mud and sand in high range.

3. Advanced Adapters Atlas II
Plus: Available in a bevy of low ranges with two or four speeds, stout aluminum case, all-gear driven, available both side drops, can handle big-block power, many shifter options available.

Minus: Won't find it in the junkyard - even second hand prices are still pretty high - and the big case means clocking it flat may interfere with the body or frame/rail.

Use it if: You've got a normal-sized Jeep with any engine or a small-block-powered fullsize.

4. JB Conversions Lo-Max 205
Plus: All the strength of the original 205, with stronger gears, stronger case, and better 3:1 gearing.

Minus: It is still a big transfer case, so fitting earlier Jeeps will be rough, and 3:1 might not be low enough.

Use it if: You've got a big Jeep with just about any engine and 3:1 is a decent low range for you.

5. Dana 300
Plus: The best cast-iron case put in a Jeep from the factory, 2.62:1 low range, ability to be twin-sticked, standard six-bolt pattern, short overall length.

Minus: Only available from 1980-'86 in Jeeps, which makes them increasingly hard to come by; stock gears and outputs not the strongest when compared to aftermarket cases, but there are upgrades available.

Use it if: You've got a passenger-side pumpkin on the front axle and you need to build a killer case a little at a time.

6. Stak 4x4 Monster Box
Plus: Three ranges (1:1 and two low ranges) mean it can be used for rocks and mud, short overall length, many shifter options, all-gear driven. It will handle a healthy small-block in a Jeep with no problems.

Minus: It's big and fitting it in some older Jeeps will be rough. Also, there is likely to be floorpan interference, and this thing ain't cheap.

Use it if: You want to use your Jeep for more than rocks and aren't on a shoestring budget.

7. Hi Impact
Hercules combo
Plus: All cast-iron, heavy-duty pieces with a Klune-V Extreme Underdrive coupled to a Bronco Dana 20. Plenty of gearing options, still fits in short Jeeps, and can be relatively inexpensive.

Minus: Added complexity and added weight compared to some other solutions.

Use it if: You aren't running a huge motor, like a bunch of different gearing options, and the idea of easy-to-find parts.

8. NP242
Plus: Full-time four-wheel drive and a low range on top of a two-wheel-drive option; this case is the case for sloppy conditions.

Minus: Some of the XJs these come out of used goofy output shafts on the transmission, which means that the inputs can be goofy.

Use it if: You do a lot of driving on-road in messy conditions.

9. Dana 20
Plus: With a decent low range in the Bronco box of 2.46:1 or an available 3.15:1 from Tera Manufacturing, coupled with an ultra short length, cast-iron case, available in driver- and passenger-side drop, and all-gear driven, this is a beefy unit.

Minus: Beefy, if we are talking stock engines ... healthy motors can blow the Dana 20 up.

Use it if: Space is at a premium, you are running a stock to mild motor, or you just want to upgrade your Dana 18.

10. NP241 HD
Plus: It lives in 1/2- and 3/4-ton trucks, so it should have no problems in your Jeep. And with a 2.72:1 low range, it's a good all-around case. The heavier case (beefed up around the bearings) and the wider chain make for a strong unit.

Minus: It is aluminum and chain-driven, so if that sort of thing bothers you, go elsewhere.

Use it if: You stumble across one that will bolt up to your transmission and aren't ready to pony up for an aftermarket unit.