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March 2013 Your Jeep

Posted in How To on March 1, 2013 Comment (0)
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It’s Just Marking Its Territory
I have a ’77 CJ-7 with the original 258ci inline-six hooked up to a T-18 four-speed. It seems like I’ve always had a drip of oil hanging on the bottom of the bellhousing. So I finally replaced the rear main seal, and even though it appears to be a good seal (there is no oil coming down the face of the bellhousing from the rear main area), there still is a drip of oil on the bottom of the bellhousing. Is it possible there is gear oil from the tranny making its way into the inside of the bellhousing, and that’s a drip of gear oil I’m seeing and not engine oil? I know very little about transmissions so I’m not sure where that leak might be, or if it’s possible. Thanks for your help!
Brett Siegrist
Via email

It’s possible. The best way to identify gear oil is based on the smell. Gear oil smells a little like rotten fish. It tastes like fishy butter, but don’t eat it. It’s not good for you. I just know since I accidentally ate some once! Yuck! You also could change the gear oil in the tranny and see if the oil that is dripping off the bellhousing is suddenly a lot clearer. Also, after changing the oil in your transmission you will know what gear oil smells like. Engine oil pretty quickly takes on a brown burnt color due to the heat the engine develops. Gear oil, unless it is pretty old, will remain honey-colored, since the tranny (shouldn’t) get nearly as hot as the engine. The transmission will have a seal at the input that may be leaking; I would not worry about fixing it unless the leak is relatively large, since the tranny will have to be pulled, and you might as well re-build the transmission (if it needs any other work), add a new clutch and so forth while it’s out. More than likely it’s just engine oil coming from the back of the valve cover.

No Love for Chrysler 8.25?
I’ve been a subscriber for years and love XJ related stories. I’ve owned an XJ since 2004 and have put 165,000km on it (360,000km in total) since I’ve owned it! We’ve shared lots of road trips and off-road mayhem. When I received the September ’12 issue, I was stoked to see the article on axles, gears, and lockers. However, I was not stoked when I didn’t see my axle get reviewed! What about the 8.25? No love? Never had one? Mine is awesome! Thanks for the wonderful magazine. Jeep girls rock!!
Jonezy Head,
Via email

Wow, we wonder how your axle would be doing if you had put miles on it rather than kilometers. The truth is we had to draw the line somewhere as to what to include in that article, and I guess the Corporate Chrysler 8.25 was just on the far side of that line. It is a pretty good axle, and Hazel, Trasborg, and I have all flogged them on- and off-road, but they do have their limits. I’m currently running one out of a ’98 XJ in Project Ground-Up. Also these axles are found almost exclusively in XJs (with some in Libertys, and WKs).

Anyway, to make it up to you, I’ll give you my opinion of the 8.25. The post-’96 models come from the factory with not-too-shabby 29-spline shafts (’96-earlier are 27-spline), making the later version of the axle hypothetically almost as strong as a 30-spline Dana 44. The ring gear is of course 8.25 inches in diameter. Not too shabby, and again, just under the size of a Dana 44. There is a fair amount of aftermarket support for this axle with a few available lockers and gearing down to 4.88. Also, the axletubes measure a bend-resistant 3 inches in diameter, which is larger than TJ Dana 44s and the turdy Dana 35 (with 25⁄8-inch tubing). And, the axleshafts are the same length side to side, making finding a spare a bit easier. Some not so desirable characteristics of the 8.25 are the C-clip axles and the lip that hangs off the bottom of the housing. If an axle breaks, there is nothing to keep it in the housing and it will work its way out of the housing. The bottom of the diff housing also tends to grab rocks. You can grind this lip off the bottom of the axle for better ground clearance. All in all, the Chrysler 8.25 is a pretty sweet axle up to about 33- or 35-inch tires depending on how hard you are on it. I would also argue that this axle paired with a non-disconnect, high-pinion Dana 30 in a ’97-’99 XJ would have been half of Jeep’s strongest factory axle combinations available in a fuel-injected Jeep prior to the 2003 introduction of the TJ Rubicon with dual Dana 44s.

Digging Ground-Up’s Groovy Wheels
Great job on project Ground-Up. That project got me buying again. The idea of white wheels with baby moons is a nice touch. I like it so much that I have called Summit Racing and they assure me they have or can get these wheels for me; the only problem is that the people I’m talking to haven’t seen the article. If you have the part number or style it would help me get the correct wheels. Again, great job.
Wendell Cross
Via email

Thanks man we love the wheels on Ground-Up too! Unfortunately you didn’t tell us what kind of Jeep you are running and different years and different models of Jeep have different wheel bolt patterns. The wheels on Ground-Up are 15x7 OE Chrysler wheels (Wheel Vintiques 63 Series PN63-571204) but those will only fit the 5-on-41⁄2-inch bolt pattern found on ’87-’06 Wranglers, ’84-’01 Cherokees, ’93-’98 Grand Cherokees, or first-gen Liberties. You may also want wider wheels if you are using larger tires. So this seems odd since Ground-Up is a ’56 CJ-5, but the axles in Ground-Up are from a ’98 Cherokee. If you have a fairly stock CJ you’ll need a wheel with a 5-on-5½ bolt pattern. Wranglers (’07- current) and Grand Cherokees sold after ’98 will need wheels with a 5-on-5 bolt pattern. Most FSJs have 6-on-5½ bolt pattern. I am sure that once you figure out what bolt pattern your Jeep has you can find some wheels just like what’s on Ground-Up. There are several Wheel Vintiques series that are similar. We like the 12 Series, 14 Series, and 62 Series. You can get them in 15x7, 15x8, 15x10, 16x8, 16x8, and so on. Summit Racing can get you any of these with whatever bolt pattern you need!

Minivan Mill Do-over?
We love our ’07 Rubicon, but have had serious oil consumption since 30,000 miles. Talking to JK owners, this seems to be a pretty common problem in ’07-’08 models. My standards for a relatively new engine and Chryslers differ by a few football fields. Instead of having a dealer tell me a quart of oil every 750 miles is ok, or bitching and moaning about it on a forum, I want to do something about it. Since I don’t have a cash tree in my backyard a Hemi swap is not my answer. Are there any rebuild kits for the 3.8L that have been on the market long enough to gain credibility? Any shops that have a good idea on what parts are suspect and best options to replace? What can I do to fix this oil eater myself and keep this ride on the trail?
B. Dutkiewicz
Huntington Beach, CA

Check out seafoamsales.com and watch the video on the Sea Foam Spray product. It should help get the carbon off your rings, valves, and valve guides. This may help a little. A rebuild really isn’t the answer since you’ll just be starting all over again. A Hemi swap can run upwards of $10,000 and the turn-key conversions are closer to $30,000. I think if I were you I would look for a super low-mileage engine out of a wrecked JK and plop it in place of your engine before I would spend time and money rebuilding. Heck, you might be able to find an engine from an ’09-or-newer JK that has whatever the provisions the engineers developed to help prevent oil consumption—assuming there is any difference. Another alternative that might be less expensive than a Hemi swap is to look into a GM Gen III swap.

For one possibility of what may be going on with these motors, we talked to Larie Tales at Jeeps R Us in Laguna Niguel, California (jeepsrus.com). He said that he has rebuilt a couple of ’07 or ’08 JK engines where excessive oil consumption was an issue. Tales says that the rods in the early JKs (and maybe later ones, too) don’t have any machining to index the bearings. These rods are one-piece units from the factory and have to be broken into two parts (i.e., a cap and a rod). The one-piece rods are only drilled to size for the bearings and crankshaft, with no machining to index the bearings. He believes that this lack of indexing allows the bearings to spin in the rod journals, heating up and burning the oil as well as damaging the rods and possibly the crank. His answer was to rebuild the engine with factory replacement rods and a crank if necessary. Tales reports that since these rebuilds, the engines seem to be cured of their oil-hungry ways.

So you can do this too if you want, but it seems to us that this is just effectively pressing the reset button and not really “fixing” the problem, if this is indeed what it is causing it. Just to make you feel better, our JK also eats more dinosaur fluid than it should…oh, and it needs a new tranny. Yay for us!

Write Us!
Got a tech question you’re just itching to get answered? Send it on in to Jp magazine, Your Jeep, 831 S. Douglas St., El Segundo, CA 90245, or e-mail it to verne.simons@jpmagazine.com.

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