If you keep that cover. Clean degrease, wire brush, clean some more and paint it with 3 or 4 (or more ) coats of paint.

 

Thanks for all the advice. Sorry to say, after hours of research, I broke down and let Ford do it and I watched the tech. The owner is my hunting building so he did it for cheap and bought my lunch. They used Motorcraft 75w140 and the friction modifier. I know exactly how to do it myself now. I am not a mechanic so after I bought the material and wasted a day off work, it was well worth the $85 I paid them. I think the fluid was about $20 a quart, $7 for RTV, $10 or so friction stuff, brake cleaner, etc. It also looks a hell of a lot easier on a rack than in my carport.

Other than thanking everyone, I wanted to share something the mechanic told me:

There is a vent tube connected to the rear diff that snaps to the frame on the drivers side right about the shock. On the end of this tube is a plastic vent piece. My was completely stopped up. It was not venting at all. The tech said it was possible my small seepage was pressure related to the stopped tube. He wasn't sure but said the tube is made to vent and could cause a seepage instead of a full blown leak. So, passing it along for your info. Might be untrue but it makes sense to me. Interested to know what you experts think about that?

Jed

 

Jed, glad you got it fixed up and learned something.

If you look back at post #4 in this thread you will see where I actually mentioned checking the vent tube. If the tube was clogged, it is entirely possible the leak was caused by pressure, but if you had not ever done a fluid change it needed to be done anyway.

The hose is directly behind the driver on the rear axle. Take a look to find it sometime and then check for blockage when you are doing an oil change.

 

Dang...... I sure missed that one. I was using your post for my parts list too. Thanks, you nailed that one.

The only thing that concerns me is that Ford used the Grey stuff on the gasket and he didn't let it sit up. Maybe 10 to 15 minutes and he pump the fluid in. He said he never had any leaks and I guess it's on them if it leaks. It's not leaking now at least.

The tech seemed to think that fluid had been changed at some point because the gasket material was different from what the factory used. The fluid was very clean. I know for sure it has not been changed in 89,000 miles. Peace of mind too.

Thanks for helping me out. I've already volunteered to help my buddy with his.

 

One other question:

Let's say the vent tube did cause the leak. If so, wouldn't the gasket be compromised and need changing ? As far as that's concerned, would putting fluid in diff before the gasket maker sat up compromise the seal....... I guess I'm wondering if the gasket can cure and re-seal in case the fluid went in too soon. .........??.??

Thanks jed

 

If your vent tube was clogged and your axle seals and pinion seal are not leaking you are LUCKY. If the RTV was grey they probably used Locktite 5699 Grey High Performance RTV. It seals almost instantly. If it does not leak right off it never will. It is really awesome stuff. The Dana-Spicer driveline shop I use puts 75W90 synthetic in with 3 Spicer posi-lubes. Put a little piece of screen over vent hose with a tie wrap to keep things out that clog it up. Check it every oil change, only takes a second.

Good luck!

 

I gave my RTV time to dry before I added fluid, not wanting to risk mixing dissolved RTV in my differential fluid.

I went with a fancy large-capacity cover, but I saw no significant change in the differential temperatures. My cover now has drain and fill plugs, but just draining and filling doesn't allow for inspection. Just thought I'd mention that.

By having the mechanic do it, you also saved a little money on nose plugs. That stuff stinks.

 

Mike, if he uses 75w/90 in the rear end he is using the wrong stuff. That goes in the front end. 75W/140 in the rear even synthetic.

 

My mistake, I think everyone has a DANA 80. If I can get another 300k using the wrong stuff I will be happy. The only thing in my front-end is a 7.3L PowerStroke Diesel.

 

Thanks. Will get wire mesh on ....