Urban Legends - 40 Jeep Myths

    Urban Legends and Technical Stupidity That Has Been Handed Down For Generations

    You know you've heard it all before, just as we have: surplus Jeeps and Jeeps in a crate for $50. Hundreds of abandoned CJ-3Bs. The '96 YJ. Tech that doesn't make sense, such as a limited slip being equal to locker, and a Dana 60 not being able to fit in a Jeep. Most of this is as likely to be true as unidentified submersible objects off the Pacific Coast (wait, the USOs actually are true...). Therefore, we've decided it's time to get to the bottom of this Jeep lore once and for all, thanks to help from some industry experts like Jim McGean of Dynatrac, Trenton McGee of Superlift, and Keith Buckley, who is a Jeep consultant. We also got the dirt from a couple of Jeep Throats!

    Does the CJ-1 exist?It was a transitional prototype between the MB and CJ-2A, kind of an MB with a tailgate. Two existed and were known as X-18 and X-19.

    Was there a '96 YJ?
    Negative. The serial suffix for 1996 would have had a "T" as the tenth digit of the VIN. And it's based on the model year, not necessarily the year the vehicle was built. For example, you may have bought a new Jeep in December of 2005, but it would be an '06 model. If you come across a YJ with a title that says "1996," you've been DMV'd.

    Are CJ-3Bs sitting abandoned in warehouses on the East Coast?
    The "discovery" of mass quantities of CJ-3Bs resulted in the Jeepgasm heard 'round the world, but the proof of all of them was based on a photo done with some basic trickery of duplicating CJ-3Bs, including inverting the steering wheel on the other side. And it's really not all that interesting a story since CJ-3Bs can be easily found.

    What about the $50 Jeeps in crates?
    Fake. At the outset of World War II some MBs and GPWs were shipped in crates overseas. They were then quickly assembled for duty. Later, the Jeeps were shipped crateless and rolling on their own. A man named Ray Crowdery had an offer of $50,000 for one of these legitimate crated Jeeps. No one claimed the prize in the 15 years it was available.

    Was there a Jeep "Bob Cat"?
    In the early 1950s there was a Bob Cat, or Aero Jeep, pitched as a vehicle "capable of unsurpassed performance to meet the current requirements of fast, speedy transportation, versatility of usage, and compactness of size." It was to be a 1,500-pound "truly Air Borne Compact Vehicle," and would share parts with the M38 and M38A1. It never went into production because the Marines Mighty Mite M-422 scored the contract.

    What's the M676?
    The Navy M676 was an FC-170; the M677 was a four-door FC-170. The M678 was a four-door van built on the FC-170 frame, and the M679 was a two-door ambulance version. All had a Cerlist diesel.

    The M151: real or fake Jeep?
    Many would argue fake, because it had a four-speed tranny with front and rear outputs, but it was without low range. Plus, early production was by Ford; it outbid Willys every year until the mid-1960s. Some would argue it was real, since it had Dana axles (although independent) and a military heritage.

    Is there a long-wheelbase CJ-2A?
    Willys made them in 1948 for the Navy as stretched carriers and they were called CJ-2E. At least that would be true if a Navy contract for the vehicles had ever been found, or if such a Jeep was seen leaving the Willys factory at any point. Additionally, in 1946, Willys standardized its design process, which meant that the model designation would have been listed in the index of calculations by model. Also, there is no engineering release number, and it would have been given a unique serial and included in the "Norton Young" (a Willys employee) factory serial number list. Experts who have seen this supposed long-wheelbase CJ-2A noticed they had later-model frames. When Willys did make extended-wheelbase vehicles like the M170/MDA and CJ-6, the company used existing body-panel dies and "flanged" in a body extension with an obvious seam.

    What's up with the CJ-10?
    The 10s were produced from 1984-1986, and most of the pickups were exported for fleet duty. The others are CJ-10As, or Air Force TUGs. Both were built on the J-series truck frame, and the CJ-10As had a transfer case with a lockout plate to hold it in 4-Lo for the torque required to drag airplanes around the tarmac.

    Was there a CJ-9?
    Nope.

    What's a Mahindra?
    The Mahindra "Jeep" is from the Indian manufacturer (started by two brothers) of the same name, and from 1947-1954 they used Willys CKDs or built these vehicles with Willys parts, eventually using their own component designs. Supposedly they built what was essentially a CJ-3B, but called it a CJ-4 and a 101-inch-wheelbase version dubbed CJ-4A.

    Did Saab-Scania in Sweden make FCs?
    Scania did receive CKDs in the early 1960s (it didn't merge with Saab until 1969). They assembled some but built others into custom configurations.

    So was there really a CJ-4?
    At least one Willys CJ-4 existed domestically and, like the CJ-1, it was a transitional model. It looked to have a CJ-3A tub and CJ-5 hood and unique fenders, all done to make room for the taller 134 F-head. Military versions were the CJ-4MA and CJ-4MP.

    What was the 1990s' Jeep JJ?
    The JJ project started with Chrysler in 1990-1991 and was to be an entry-level Jeep. It would be stripped of a two-speed transfer case (sound like any upcoming Jeep?), and it used a Chrysler transaxle mounted longitudinally to drive the front and rear axles instead of the right and left front half-shafts. The JJ never saw production because of unfavorable investment requirements--in other words, when Renault didn't want to do a joint venture with Chrysler, it was kaput.

    Rare Jeeps are valuable, right?
    Not always. We know someone who had an extremely rare model in near-mint condition, and he had the thing priced to steal (everywhere from local ads to eBay), but it sat for more than a year without a single phone call from collectors--or anyone.

    Tech Editor Hazel is an idiot because he chopped up a one-off Jeep, correct?
    His two-wheel-drive DJ has since been said to have been a prototype worth about $10,000-$15,000. But since he hacked it up, it's worth...well, it doesn't matter since it was the only one in existence anyway.

    How did the Jeep get its name?
    The long-standing stories are either GP (general purpose) or the 1930's cartoon character, "Eugene the Jeep."

    Was a big-name off-road magazine's project vehicle responsible for inspiring Jeep to build the Wrangler Rubicon?
    Many Jeep employees actually wheel Jeeps for fun (which results in R&D)! Someone who worked on the '70s CJs and who had paired a Dana 20 2:1 transfer case with 2.73 and 2.87 axle ratios was also the first person at Jeep to experiment with a 4:1 transfer case, selectable lockers (ARBs), and 4.10 axle ratios in his personal Jeep.


    Did some CJs come from the factory with an AMC 360?
    Sorry, only the 304. Some dealers may have swapped in a 360 or 401, such as Randall AMC/Jeep in Mesa, Arizona. Was a barrel found in Australia containing Willys-Overland Jeep side steps?
    Yes, although they were only the bottom part without the supports. Plus, they were later-production parts with a different diamond pattern on them.

    Does the external oil filter on flatfenders need to be removed because it starves the front bearings?
    The bolts that locate the rocker-arm pivot tube on the F-head are tapered. Rebuilds or servicing often resulted in straight bolts being used instead, so the rocker arm would move out of alignment, which would cut off the oil supply to the rockers; the first rod bearing to spin was always the number one because it was starved. Leave the oil filter alone.

    Did only one gear ratio exist for the T-90 three-speed?
    No. When the front and rear drive axle ratios were changed from 5.38 to 4.27, the First gear ratio in the T-90 was changed from 2.798 to 3.339. The only way to improve the crawl ratio of the flattie was to use a later transmission assembly.

    Is it true that Dana 60s are too big to fit in a Jeep?
    A factory Dana 60 housing hangs only 3/4-inch lower than a Dana 44's, and only 1/4-inch lower than a Ford 9-inch's. So, if you want to run a Dana 60, run it.

    Can a bead lock bolt loosen on its own?
    Properly manufactured bead lock wheels have a ledge to clamp the tire bead on both sides, and as long as your tire has the correct molded bead ledge width and the bolts are properly torqued, there shouldn't be a problem. Although, if they're overloaded it could happen, and in general, it's still smart to check them every so often since grinding them on trail obstacles can loosen them.

    Is a diesel engine better than a gas engine on the trail?
    Swap in a lightweight diesel mill without turbo lag and the answer is yes, it very well could be better. The kick-butt torque and fuel economy would make it totally desirable.

    The M715's NP200 transfer case will eat itself alive because of non-helical gears, right?
    Don't sweat this. They are helical gears, which are generally stronger because they spread the load over several teeth but side thrust results from the helix angle, and they're more complex to manufacture. The main reason helical gears are even used is because of that strength and the quieter operation (because of the load being spread over several teeth).

    Is a limited slip as good as a locker?
    If you're able to multi-task and get the brakes and gas going at the same time, you can make that limited slip get power to the opposite wheel. But forcing the open diff to work in an unnatural way (and on major obstacles) will wear out the clutch plates. A locker will create good traction to both tires, without requiring your footsie balancing act.

    Is 4:1 low range in the transfer case better than 2.72?
    Sure, the 4:1 will offer a better final drive ratio for stupid human tricks that require lots of torque, like on rocks. But if you want maximum wheel spin in, say, a mud pit or sand, the 2.72s will be crucial to success.

    Is a reverse-cut housing the same as a regular housing except that it's mounted upside-down?
    Reverse-cut or high-pinion housings have their very own design and require special ring-and-pinion gears. Therefore, you can't use a standard-cut (low-pinion) gearset in a high-pinion housing. And, no, you can't flip a standard cut and expect it to behave like a high-pinion housing. High-pinion axlehousings have different oiling passages cast in them for pinion lube than the low-pinion housing's, so flipping a regular housing means the pinion bearings won't get lubricated and the bearings will basically weld together. And, worse yet, it will rotate the tires in the wrong direction.

    Are all Dana 44 axle assemblies the same, other than widths and spring-pad positions?
    They generally share only one thing: ring-and-pinion gears. Knuckles, spindles, brakes, hubs, and so on are not always interchangeable between vehicles.

    strong>The CV driveshaft provides more angularity, right?
    The rule for conventional driveshafts is equal but opposite angles at the ends. In other words, a CV shaft should be set up with the axle pinion 1-2 degrees down from parallel to the driveshaft. New hybrid CVs can typically handle more angularity than a regular shaft, but it doesn't mean you'd be able to use it if you can't rotate the axle up to match. Short answer, no.

    Was there a "shorty" Dana 300 transfer case used in the CJ-5?
    Yes, for a couple of years. It's about 2 inches shorter than the conventional 300's. It's rare to find. The tail unit of the shorty is tapered and cast-iron, and the front bearing on the output shaft has an ID of 1 1/8 inch, while the longer shaft's is a beefier 1 7/16 inch.

    Desert-racing parts aren't meant for rockcrawling Jeeps, true?
    True, just like drag-racing parts aren't either. Inspiration can come from not only the automotive world, but also the likes of marine, racing, low riders, DUBs, and even those USOs. Hey, if it's a good idea, the ways to adapt it for Jeeps are endless (and if you pull it off, it could make you rich, famous, or a future urban legend). While you may opt to modify yours to be a dedicated rockcrawler without a need for speed, we're talking about parts in general that can be borrowed from that venue and work.

    Is the Dana 44 in the Wrangler Rubicon stronger than the Dana 30 in other TJs?
    The Rubi does have a true Dana 44 ring-and-pinion inside, but the front housing uses the same 2 1/2-inch x 0.25-inch wall tubing, knuckles, outer shaft, and U-joints as the Dana 30.

    Will fuel economy get better with a low-temperature thermostat, especially with fuel injection?
    No. The various temperature sensors will keep the engine in cold calibration (running richer) and might not let the closed-loop function enable.

    Are 4.56, 4.88, 5.13, and 5.38 gear ratios too low for street driving?
    Most 4x4s made since the early 1990s are equipped with an automatic or manual Overdrive transmission, and the majority will create a 20- to 25-percent Overdrive that will make any vehicle with 35-inch or taller tires a good candidate for any of those gears.

    Are kingpin knuckles really stronger than ball-joint knuckles?
    When the open-knuckle kingpin and ball-joint axles arrived with bell-bottoms in the early 1970s, many hung onto the old closed-knuckle style, but ball-joint knuckles are found everywhere and are just as strong.

    To have a spring-over suspension, can't you simply weld new perches on top of the axles?
    Sure, and with this type of modification, the magic fairies sprinkle dust that makes it unnecessary to worry about axlewrap, brake lines, steering, and driveline angle, among other things.

    Swapping out a Model 20 rear axle for a Dana 44 is a good upgrade, right?
    Yes. But they are similar in strength. In fact, the ring-and-pinion in the 20 is actually larger than the 44's. As for spline count, the 20's is at 29, while the 44's is at 30. You can eliminate the 20's major flaw (two-piece axles) with a one-piece replacement kit. However, the 20 hosing is generally weaker than that found on late model Dana 44s.

    Is it true that it's not actually a Cadillac at the bottom of Cadillac Hill on the famed Rubicon Trail?
    The vehicle pushed off the cliff was, indeed, a Cadillac LaSalle.

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