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March 2011 4xForums - Letters to the Editor

Posted in Features on December 8, 2010
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Send questions, comments, and suggestions to: 4 Wheel Drive & Sport Utility MAGAZINE, Attn: Christian Lee, 1733 Alton Parkway, Ste. 100, Irvine, CA 92606, or

Pinion Depth Tools & Early Jeep Grilles
Q: I am working on a 1942 Willys MB Army Jeep. It is the early-style MB with the slat grille rather than the traditional Jeep-style grille. I read in a book that there are only about 200 of these that survived. Is this a realistic number? I am currently working on setting up the rear differential, which is a Dana 23-2. Who makes a pinion depth gauge with the right size of cups that go in place of the carrier bearings in order to measure the distance? I have seen the gauges that have a swing-arm type of assembly but I'm not sure how they work. Any help is appreciated!
Tyler Nighswonger
Via email

A: Tyler, I couldn't begin to assign a number to how many original MB grilles are still in existence. If you have one though, consider yourself lucky. Only about 25,000 of the original flat iron slat grilles were produced, and by 1942 most MBs were receiving the more traditional-style slat grille. Interesting to note, it was actually Ford with its GPW that created the very-familiar nine-slat grille, which Willys adopted and eventually changed to the seven-slat grille still in use on Jeeps to this day.

Concerning your Dana 23-2, the tool you are talking about is a dummy differential set-up tool, which usually includes arbors (dummy bearings) that fit the bearing cups and a depth gauge so pinion depth can be determined. However, most of these types of kits are made for newer axle assemblies. As you mentioned, you should be able to use a swing-arm type tool to accomplish this task. Miller Special Tools [(800) 801-5420,] offers a large variety of "dummy" bearings to fit many applications as well as the necessary set-up tools and gauges either in kit form or sold separately. As for a "swing-arm" style pinion depth tool, you may be thinking of a dial indicator with a magnetic base, which is used to check pinion backlash. However, Proform Tools [(586) 774-2500,] offers a reasonably priced universal pinion setting tool that should do the trick. It secures to one of the carrier strap bolt holes and uses a gauge to determine the pinion depth.

For those not familiar with the Dana 23-2 axle, it is a full-floating rear unit that was used in 1941-to-1946 Jeep MB and CJ-2A models, as well as the Ford GPW (called the GPW-4001 axle). Considered a light-duty axle, it used a 7 3/4-inch ring gear and came equipped with a 4.88:1 gear ratio. It is a fairly rare application and parts availability isn't vast. The best selection of parts we found for this axle was available through Mid West Jeep Willys [(630) 529-2116,] in Roselle, Illinois.

When you're ready to share, please send us photos of your rare rig. Thanks for writing. 'Wheel on.

Swapping Jeep Parts
Q: I was looking at your upgrades on the '02 Jeep Liberty (air-intake system and Magnaflow exhaust) and noticed that you have upgraded the drivelines as well. I was hoping that you could tell me where you got them and what they are? I notice they say on them, but I can't see any products for a liberty there so I am assuming that you can swap parts from one Jeep to the other it is just a bit over my head, and I don't know how to find out what parts that interchange. Thanks for your help.
Spanish Fork, Utah

A: Wade, yes, you can swap some parts from one Jeep to another, but only to a certain extent and usually with a bit of massaging. In addition to the intake and exhaust, the 2002 Jeep Liberty shown in the article you mentioned was equipped with a Klune-V underdrive, an NP231J transfer case with a slip-yoke eliminator (SYE) kit, and new front and rear driveshafts from J.E. Reel Drivelines. A CV-style driveshaft was used up front and both front and rear use 1310 yokes. The Liberty intake and exhaust article is from the January 2007 issue. The Liberty transfer case and driveshaft swap is from the November 2006 issue. Both articles can be viewed at

In stock form the Liberty uses a NV242 transfer case. With or without completing the transfer case swap you could apply similar upgrades to your Liberty, such as an SYE kit to eliminate the long slip-yoke rear output on the transfer case, and heavy-duty U-joint-equipped driveshafts like those shown in the article. To install new driveshafts you will also require the appropriate yokes for connection to the axles - most reputable driveline shops will offer or can help you track down the correct yokes. For more information about the Liberty drive shafts, contact: J.E. Reel Driveline Specialists [(909) 629-9002,]. For SYE kits for the NV242 transfer case as well as driveshafts, contact: Tom Wood's Custom Drive Shafts [(877) 497-4238,].

The phone number for John Williams at Impulse Off-Road was printed incorrectly in a previous issue. His number is (801) 599-1609. We apologize for any inconvenience.

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