What's The Best Diff Cover?

someguysjeep said:
not really related to the subject but i came across a diff cover test.
the test was particular about flat face diff covers and how when running the lube is slammed into the flat face of the inside of the cover instead of being channeled up and around the ring gear like it should be thrown.
the gear lube was just slammed into the flat face causing all kinds of aeration to the fluid, which in turn lowers its viscosity, the slamming causes the lube to be thrown in all directions instead of being directed over the ring gear and into that pinion oil galley.

those round face covers allow the lube to impact and follow the curve up and around and then contact the ring gear again to be thrown forward. the lube has to make it over the gear.
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Gale Banks did that test - and it sure got my attention. Which is why I chose covers that are more or less stock in (internal) shape.
 
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I like the yukon doff covers for the recessed bolts, granted they aren't the only ones with recessed bolts. I had solid diff covers and beat the hell out of the bolts, always needed vise grips to get em off.
 
This is one I made for my XJ before I went to a solid cover. I swapped in a hp Dana 30 and kept the lp cover. Chopped it and spaced it out with washers.

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I would stay away from the Dana diff covers @phraza . I have them front/rear and my front one takes a beating. Upon my last post trail inspection i noticed the drain plug had started to back out. I don't know if I kept hitting it and that did it or something else. I know I installed it correctly. I have a metal cloak one ready to go one. It has a flush drain plug and mounting bolts.
 
nceagle03tj said:
Hey Y'all,
I'm going to be getting new gears and installing lockers on Daisy sometime in the next few months, I'm just curious on what your go to diff cover is.
I know it's not something your always buying but I'm looking for strong and reliable. I've herd the ARB are good but just wanted fellow jeepers opinions.

Thanks Y'all!
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A lot of people will say their cover works great. That is user experience and helpful as far as that goes. There are 2 considerations though:

1) the Banks test. This test showed that the shape of the inside of the diff cover affects the movement of the diff oil. As the rig gear turns it throws oil against the cover. Stock covers have a channel for the oil that funnels it up and over the gears. This helps keep the gears cooler. A cover without the channel causes aeration and loss of viscosity.
2) Clearance. There is often a clearance issue between the tie rod and/or trackbar and the diff cover. Large bulky covers are often a culprit and should be avoided, especially if you are planning to further modify your Jeep.

I think a minimalist approach is helpful in this case. The 5/16” US Alloy is a good choice for a Dana 30 or 44. For a Dana 44 the Ram 1500. Barnett is a modified stock cover and another great choice, especially for sliding over rocks and protecting the underside of the diff. If you have clearance, one of the half guards by Warn or RockHard 4x4 will be fine.
 
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JMT said:
A lot of people will say their cover works great. That is user experience and helpful as far as that goes. There are 2 considerations though:

1) the Banks test. This test showed that the shape of the inside of the diff cover affects the movement of the diff oil. As the rig gear turns it throws oil against the cover. Stock covers have a channel for the oil that funnels it up and over the gears. This helps keep the gears cooler. A cover without the channel causes aeration and loss of viscosity.
2) Clearance. There is often a clearance issue between the tie rod and/or trackbar and the diff cover. Large bulky covers are often a culprit and should be avoided, especially if you are planning to further modify your Jeep.

I think a minimalist approach is helpful in this case. The 5/16” US Alloy is a good choice for a Dana 30 or 44. For a Dana 44 the Ram 1500. Barnett is a modified stock cover and another great choice. If you have clearance, one of the half guards by Warn or RockHard 4x4
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Clearance is a big issue.p.o had a dropped track bar bracket that hit the cover. I removed the dropped bracket/pitman arm and installed JKS adjustable track bar.

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Those videos showing gear oil flowing in the diff aren't worth a second thought. How does that work on the front axle which is half of what we are talking about, oh ya, it doesn't.
 
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