Since I lifted my 95 the rear diff is visible and looking kinda shabby. The rear diff cover is rusted big time and starting to weep gear oil. I didn't want to put a chrome cover on it or fork out the dough for one of the trussed aluminum covers, so I just went to the dealer and bought a new cover and gasket(the new cover is bare steel) I also noticed that the rear end is weeping gear oil around the axle tubes at the diff housing. My plans are to just clean the entire axle with purple stuff and paint the entire rear end with semiflat black primer. Just to add a little contrast, I want to paint the diff cover a gun metal gray color and paint the diff cover bolts semiflat black like the rest of the housing. My question is how well is the semiflat primer going to adhere to the cast diff housing which has that nice rust color to it now? I don't really want to pay someone to sandblast the housing. I'm trying to make it look as nice as possible without forking out a bunch of money as I will be wheeling this offroad from time to time. I don't want it to go back to looking like junk either(rust) Any recommendations?

How about sandpaper and that brake caliper spray paint people always use?

High temp paint really is not necessary. I would use something like the Chassis Black you can get from Eastwoods. Covers nice on rough metal.

I would definitely recommend a wire brush or better yet, a wire wheel on a 4" grinder to clean things first.

Check out my Rear Axle Service article in the Tech Article (DIY) section for the cover and diff cleaning portion.

Check out my Rear Axle Service article in the Tech Article (DIY) section for the cover and diff cleaning portion.Thanks. I'll be checking this out.

The problem with your plan to paint the diff with primer is that primer is not durable. It will allow moisture to soak through and the rust will come through from under the primer.

The process I have had pretty good luck with is:

1. wire brush the loose rust off. Get down to a good surface
2. wash it down and let it dry
3. use a good heavy duty rust resistant primer. The oil based rustoleum primers are good for suspension parts, but don't use them for body work, because they will bleed through some automotive paints
4. paint with an enamel paint. enamels are durable enough for suspension parts, even if you off-road. There are flat enamels available if you want the flat look. Rattle can enamels are convenient for a quick, easy to respray after a summer of running trails.

Durable paint doesn't have to be expensive. We once did a gas tank that was visible under a back bumper by spraying it first with black, then taping an old lace curtain that we found in the trash over it and spraying it red. Came out looking like black lace. We used cheap rattle can paint, and it lasted four years, looking pretty good from ten feet away.

I find it much easier just to keep everything covered in mud. Also helps to keep the many scratches cover up, too!

I find it much easier just to keep everything covered in mud. Also helps to keep the many scratches cover up, too!
lol i like that idea as well :)

After i noticed my gear oil leakin from the bottom of the rusty cover...got a new one washed ..primed..and painted with rustoleum enamel ...sorry about the big pic.
http://i187.photobucket.com/albums/x169/zeedeevil21/th_0327091832.jpg (http://i187.photobucket.com/albums/x169/zeedeevil21/0327091832.jpg)

Looks good!