The shop installed my finned cover as shown on page one post #13 of this thread. https://www.ford-trucks.com/forums/7...iff-cover.html...they reason that I had them install the finned cover is because when they did my gear swap last year...the original flat diff cover also developed a leak...so while they were fixing that leak...I simply asked them to re-install this cover instead of the original...they agreed...



However I developed yet another leak in the cover after a very short time (bottom most bolt)...as you can see in that photo there seemed to be a good bead of (baby blue) permatex...

So I called the shop and they agreed to take a look at it...they removed the cover and re-installed it...this time they used black permatex...(so Bob...I don't have that baby blue any more! hehe...

However I was just out waxing the Ex getting her ready for snow/ice duty and I noticed a small leak yet again...this time it is the bottom right side bolt that appears to be leaking.

My question is...does this shop just not know how to seal a rear diff cover?

Each time they do this it takes $60 worth of synthetic diff fluid (at their cost)...I have to believe they are going to tell me to go pound sand here even though it is THEIR mess up each of these times...

They claim they torque'd the bolts to the required 24 ft-lbs for this aluminum SD diff cover versus the 38ft-lbs for the original flat stamped steel one...

Should I simply snug that one bolt up a little to see if I can get the leak to stop?

What do you guys think?

Thanks in advance for the ideas/suggestions.

joe.

 

I would first call the shop and tell them the situation. This cover if properly installed should not leak. They probably either didn't wait long enough for the rtv to cure a little,or they did not put enough rtv around the holes of the diff cover. If they wont deal with you, then try tightening the bolts in the area around the leak a little and see if that works. Also to save money you could pull the cover off yourself, and re-claim the oil that comes out because it,s still good and re-use it. Clean both the diff cover and the sealing area on the diff housing, and buy some good permatex silicone and apply to diff cover and make sure to go around the bolt holes and install. Let the silicone cure for an hour and put the oil back in. That will be the hardest part unless you can find a clean squeeze bottle or somthing that resembles the original bottle. You could also try a small funnel, but this will take more time. It's not that hard. If you do this remember when looseing the bolts leave a couple of the top bolts on, but loose and with a pan under the diff slowly break the seal and allow the oil to come out slow. Once you have the flow under control you can pull gently on the cover until the oil is comming out at a controllable pace and then remove the last bolts and pull the cover. If you have any doubt's take it in. You dont want to be stuck in your driveway with a rig that wont move. Wish I was there to help you out. Good luck.

 

I know synthetic motor oil will find the smallest area to leak out of, wondering if synthetic diff. oil does the same?

 

I always find a time when I can install differential covers late in the evening allowing the sealant to cure overnight. I also clean the mating surfaces with brake cleaner etc. to make sure there is no oil residue. I've never had a leak doing it this way.

 

Joe, that looks good on there.

 

Thanks for the quick responses...

skullonarm...I wish you were closer too!...I've given out too much rep for today but I'll be sure to hit you with some forum kudos tomorrow (I reached my 24 hour rep limit again!!!)...for your help!

I just went out and gave the one bolt that was leaking a little snug...figure I'll watch it again to see if that stops the leak...if not...I'll call the shop to see what they say.

Scott...thanks!...if I can only get a tight seal I'll be happy!!!

Joe.

 

Seems there'd be a better design for the rear diff cover and its mating to the diff body itself.

 

There is a better way. It's called a gasket. The manufactures on a lot of vehicles only use silicone on tranny pans and diffs. When I worked at dodge I hated putting pans and diff covers back on with only permatex. It sucks and when your trying to make a living at doing this you don't want customers to come back for a leak on something you just worked on. When I was in the Coast Guard, and was deployed in the Arctic Or Antarctic or some other misreble place we carried a warehouse of parts but still had to make or own gaskets on a lot of stuff. You can do it at home also. Go to a parts house and ask to buy some gasket material for the purpose you need. Then just cut a square out of it and place on the surface you want a gasket for. Now the fun part. Now you get to use that old ball peen hammer that you had no idea what the ball end was used for. Besides flattening out rivets they work good as a gasket maker. Just tap the ball end of the hammer against the sharp edge of the surface all the way around, outside and inside. Then take the middle out and discard. The ring shape or whatever shape it is will match the surface. keep the gasket in place and where the bolt holes are use the ball end of that ball peen hammer and again tap the gasket material until the material goes into the bolt hole. Make sure to keep the gasket material lined up when doing this our the bolt pattern wont fit. Clean out the bolt holes with a pick, and use the messy silicone on both sides of the gasket and there you have it. I do this weekly on some of the old crap I work on. Afterwords sit back and have a cool adult beverage and admire your handiwork. It really will make you feel good that you out foxed those engineers who forced you into this situation in the first place. Your the winner!

T. Moe

 

Sheetmetal screws, Joe. For a job like this, duct tape won't cut it, so use sheetmetal screws.



Stewart

 

Wait! I know!! Use a couple of these!!!



Stewart

 

Two words buddy...

Oh ring!



Stewart

 

You can always leave the cover off. Then you'd really have an "open diff"!

BAHAHAHAHAHAHAHAHAHAHA!

Stewart

 

Some of those bolt holes go clear through the housing, If I where you I would remove only the bolt that is leaking and clean it up and put a little RTV sealant on the treads and then keep an eye on it. If it is just that bolt leaking that should solve your problem and no need to remove the cover again. Good Luck.

 

I agree like you did. Tighten it up a bit and recheck. Then call the shop to get their take on all this. Then if still leaks seal it up good yourself like T. Moe said. It sounds like they didn't clean the surface completely before they reinstalled the cover. With the cover off the chunk will drip for a while unless you get all of it out and clean the whols thing inside and out.

The hammer works well but if I were to make a gasket I would lay a sheet on the table and put the cover on top. Then using a razor cut around the edges. While the cover is on there mark where the bolt holes go. Then measure how wide the sealing surface needs to be then trim the inner part out. Next is the bolt holes. Get an old shell casing, in this case I believe a 25 cal. sholud work. Use your best judgement on that. I believe a 9mm might work but may be a bit big. Then put the shell end on the spots you marked and tap with a hammer. Voila clean hole

P.S. Be absolutely sure the shell is used and empty. Otherwise you will make a bigger hole than you wanted and it may make more than one hole.LOL

 

Good One!!!