One thing about my TJ that drove me absolutely batty was the fact that the drain plug, no matter how much you sweet talked it, would never perfectly seal the opening in the oil pan. This resulted in very regular (every other day?) oil cleanings of my garage floor. So you might be able to imagine when the JK started to leave me little pictograms made of oil on the floor at around 8000 miles on the clock, I was less than amused. What can I say? I keeps it tidy. The JK’s drips weren’t coming from the oil pan, but the rear diff. No problem, I’m under warranty. I’ll just let the Jeep boffins take care of it. But the more I stared at it, the more I wondered why bother fixing a sub-par stamped metal part? Equipment failure can be an excuse to upgrade, even if the failure is just a simple gasket.
A heavy duty diff cover is a relatively ‘low cost/high protection gain’ product and as I looked around I saw many, many options. That ARB one sure is pretty, but after the rear bumper head ache I don’t know if I’m ready to trust anything from ARB just yet. Why the hell is the Mopar piece so much more expensive than everything else? The Riddler piece looks nice and I also really like the Poison Spyder Bombshell (both have recessed bolts & rounded construction). Too bad the PS diff cover won’t fit with an OEM track bar. In the end, the best bang for the buck was a cover from Solid Axle Industries. Not only was it on sale for $65 (beating out the next closest competitor on my list by over $30/axle), but it can actually withstand a .454 Casull at 30 yards.
I took a look at this write up, called my buddy for a spare set of hands (Thank you Scott!), cued the theme music, and got to work.
Lately, regardless of the situation, my optimistic catch phrase seems to have become “hell, it’s only 8 bolts!” but in this situation, it actually applies. 10 bolts around the edge, 1 fill plug, 1 drain plug, and you are done. I CAREFULLY lined up the oil drain pan below the rear diff to catch the oil, and then slowly loosened the drain plug to try to prevent any spillage. The “oil” pouring out of the rear differential was absolutely disgusting. And when I say disgusting, I don’t mean it in a dainty ‘oh look, this oil is dirty’ kind of way. I’m talking the dregs of a port-a-john at the end of week long intense Burning Man Festival level of filth. What do the fine folks at the Jeep plant use to fill rear diffs? How the hell can it be THIS bad after only 8700 miles? I was so shocked at the black sludge pouring out that I didn’t even notice as it perfectly missed the oil drain pan and covered my floor in a shade of black that could have made Darth Vadar jump for joy.
With the “oil” drained and the spillage crisis averted, I popped 9 of the remaining 10 bolts. This next part is a trick I read on a forum, and let me tell you it is fan-freaking-tastic! With only the top bolt holding the cover on, I took a hammer to the cover to loosen it from the axle. After a few whacks, it popped with a very satisfying ping of metal but swung slowly back and forth on the top bolt that was left in. Had I had removed all 10 bolts instead of 9, that thing would have bounced off my gears and flown across the garage. Now pull that last bolt, grab your diff cover, and it’s time to take a look at your gears for the first time!
In addition to scraping off the gasket residue, I like to take a look at my gears using brake cleaner to get all that gunk out. Ooooh… Shiny! If you aren’t sure if it’s clean enough, clean it some more. The last thing you want is any debris or dirt in your gears.
It’s good practice to test fit (everything!) it to make sure you didn’t fat finger your order and grab a cover for a Dana 60 while you were day dreaming and to also make sure your track bar clears it. Sure, it’s a little annoying to get your Jeep on the ground to move your track bar just to lift it back up onto the jack stands, but it’s important to check clearances now rather than find out the hard way on the trail.
With the test fit complete, it’s time to clean out both the gears and the new diff cover with a little more brake cleaner. You know, just for good measure. Once dry, apply your RTV (I’m using Permatex Ultra Black, but a tube does come with the cover from Solid) carefully not getting any in the bolt holes. This is an important step, so make sure to take your time and get this part right. After your RTV is applied, quickly (don’t run, but don’t dilly dally either) line up your cover onto the differential and finger tighten the bolts. This is another step where a spare set of hands can make life so much easier.
Following the instructions, tighten the bolts in a star pattern. If like me, you are using an OEM track bar it can really get in the way. Something that really helped me out was to use a jack and jack stands to adjust the height of my Jeep on the passenger side to move the track bar up or down a bit. There were always two or three bolts that were blocked by the track bar at any height, so raising/lowering my Jeep a little always gave me a clear shot at all the bolts. Take your time because you really don’t want to strip or cross thread any of these bolts by accident. That’ll make for a bad day. With all 10 bolts tightened to 25 lb-ft, it’s time to install your drain plug. Let me say that again, don’t forget to install your drain plug!
When topping off your fluids, it is incredibly helpful to have a pump that attaches to the gear oil bottle (Thank You ScottC!). For gear oil, I went with Royal Purple 75W140. I wanted the heavier weight since I do trailer fairly frequently and have been finding myself off road quite a bit too. I don’t want to take business from local auto parts shops, but this much oil is actually a big cost of the job and you can find a much better deal online. Pepboy’s wanted around $22/quart vs. $15 online and when you consider you’ll need almost 3 quarts (4.75 pints), that’s savings worth looking into.
The cover really is very solid (lolz!) and looks great on the axle imho. If I had to pick something I didn’t care for, it’s that the cover sticks down about 1/16-1/8” (guessing here, I haven’t measured it yet) below the rear diff. I know, it’s not much but it’s enough to catch on a rock when you are in a rock garden or a tricky crossing. Outside of that little nitpicky detail, I’m happy with it. So much so that I ordered another one for the front the very same day I installed this one on the rear Dana 44. Matchy matchy!