Diff cover protection

So I'm curious what the guys have to say. On my local Jeep forum (mostly TJs and JKs) they were debating the best diff cover for the axle.

I suggested taking a second factory cover, cutting it in half, getting some longer screws and bolting the bottom on, so the bottom of the diff cover is 2x as thick. Suggested he could do his front and rear that way for under $20. So another guy got in on the discussion (drives an 08 JKU) and this was the back and forth:

His response:

Yikes! I don't recommend doing this. Sorry that is not a good idea.

My response:

And why not?

His response:

It's not going to fit flush and you are only protecting the bottom half of the diff cover

My response:

Maybe not completely flush, but the inside cover is going to be sealed to the axle and keep the diff from leaking. And regarding just protecting the bottom half of the cover, I don't see that as a problem for 2 reasons. 1). there is no fluid in the top half of the differential, so if you puncture that part, you could feasibly get home with a small piece of scrap JB Welded to the cover. 2). if you hit something that punctures the top half of the differential cover, you will have bigger issues than just a hole in your diff cover. That is pretty damn high for a rock to take out without taking out a whole lot of your steering components first.

So, my question to y'all...since I have a spare diff cover ready to go on next time I do diff service....am I overthinking this and is it truly a bad idea?

Nope, perfectly fine ... that was common practice before the new heavy covers became readily available, even better yet is to leave a full strip over the ring gear bulge. You may need to add a washer between the two covers as they won't likely "stack" properly. Or, you could trim the bolt flange off the second cover and weld the new guard portion to the old cover. Still not as beefy as a heavy duty cover but perfectly fine (although for the effort just weld some plate over the thing.

I just take JK guys "expert advice" with a grain of salt ... although, technicly, I am one as well (the wife drives a JKU - we ARE a jeep family).

I was going to do the same thing due to my OTK steering and WJ swap creating clearance issues ... but I picked up a Poison spyder cover ... if it doesn't clear I'll double up covers and the wife's JK can have the Bling.

I don't think it would line up like you are thinking. I don't see the holes lining up, or it seating right. Part of my reason for getting bigger diff covers was rigidity, to help keep the insides together. I don't see this helping there either. Just my.02

I took my friends D30 cover and just welded some 1/8" over the ring gear bulge.

Worked well enough.

jrowell said:

I don't think it would line up like you are thinking. I don't see the holes lining up, or it seating right. Part of my reason for getting bigger diff covers was rigidity, to help keep the insides together. I don't see this helping there either. Just my.02

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This was a tried a true practice for years ... the inside cover is the only one that seals and contains ... the outside cover portion protects. As they came from the exact same stamping they do indeed stack and line up perfectly fine. The only concern would be when using a full cover ... then you would need to open a hole for the inside covers fill plug.
This isn't some new fangled Idea, this was old school back in '99.

I guess i do recall seeing a stack of diff covers...

Here's a couple examples ... one used nuts for spacers, the other washers

http://www.cherokeeforum.com/f59/homemade-diff-guard-167880/

http://www.jeepforum.com/forum/f19/poor-mans-diff-skid-652029/

You can't blame the JK guys for dodging a cheap trick. They're always looking for an excuse to spend $300 for a part with a laser-cut spider on it.

MoparManiac said:

I took my friends D30 cover and just welded some 1/8" over the ring gear bulge.

Worked well enough.

Click to expand...

On a cheap DD, this is all you need. I did mine with some 3/16 across the center and some 1/4 around the lower bolt holes to keep the bottom of the cover from peeling back. Took some fairly heavy abuse and hit ALOT of rocks at Rausch Creek.




Now on a big boy rig, RuffStuff covers all the way. Thick, simple, and strong. Countersunk bolts and no drain hole. Adding bonus for me, easily weldable for adding things like hydro ram mounts and such.