Sonoma rear diff leak

Decided to slap some JB on it, as a stop gap measure. Cleaned up/sanded the spot, and just put it on. Hopefully it works fine. I’ll keep everyone posted when I get the new cover👍

SuperSherman44 said:

Quick update. Before I went in for the night, I decided to check the diff’s fluid level. It was right up to the top, so at least that’s good. I also looked closer at the moisture spot. And lo and behold, there’s a tiny hole that looks like the diameter of a thumbtack right in the middle of the moisture spot. Definitely the culprit. There also is two little dents, (one of which the hole is in the middle of) on the cover. Now, this would be a very easy fix, just replace it and be done. But, the problem is that the bolts holding it on are in such bad condition, that I fear they’re gonna just either snap off, or the head will completely round. Idk what I’m gonna do. Anyone got ideas? I do have a mig, so if I attempt it, and they snap, I can weld a nut and all that.

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We get that perforation here on the coast of ME, in fact my '96 from NC is doing it now. Rust goes in from the outside, we have to replace the cover once or twice in a vehicle's lifetime. An acquaintance blew his rear end because he never knew it was leaking. A quick temporary fix is to gently hand sand/clean it real good, wash with Prep Sol, then use POR-15, and when that begins to tack up, lay an appropriate just-big-enough patch of fiberglass on the pinhole area, then another coat or two of POR, then let that cure long enough. I did one that way years ago and it never leaked again, made it to vehicle salvage day without another leak. Same thing happens with the bolt heads, they rot off round. Before trying any wrenching I use a stout punch and heavy ball peen hammer just in the center and jar the bolt straight on, not an angle or on the edge, to jar any rust bond loose; rust is a crystalline structure that expands as it forms, compresses everything, but does not hold up well to jarring. (Some might think that the punch and hammer are my only tools, not so, but it is one of the selective-use ones, and it can work.) Vise Grip makes an interesting tool for hex heads that can help, like #4LW locking hex wrench. Before putting a new cover on, I remove the factory junk paint, scuff it and coat it real good with Eastwood chassis paint or something good. And new bolts, then hit the bolt heads with a CRC brand waxy undercoating so I can get them off next time.