Jeep Tech Questions
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!
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!!
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.