Diff is puking oil

[2011 gtcs]

So I took my cobra on a good cruise up north over the weekend and I noticed when I get home the back bumper was covered in oil, so I peaked underneath and saw my pipes and diff were covered in gear oil. I cleaned everything off and I can't find anything wrong. Does the IRS diff have a vent hole on the top? Or is there any known issues with the diffs leaking oil out of the speed sensor? I'm just not sure what's going on

 

[Dave.O]

yes to vent tube.
On upper passenger side of diff cover, anout 1:30 ish...
Make sure tube is attached, or you may need a longer tube or catch can.
I have a catch can on mine

 

[2011 gtcs]

yes to vent tube.
On upper passenger side of diff cover, anout 1:30 ish...
Make sure tube is attached, or you may need a longer tube or catch can.
I have a catch can on mine

OK that makes sense. I put about 300 miles on it so I'm sure the fluid got hot. I'll definitely look into a catch can.

 

[01yellercobra]

Was there any work performed recently? If so there's a chance it was overfilled. A normal cruise shouldn't cause the fluid to get hot enough to spew like that.

 

[2011 gtcs]

Was there any work performed recently? If so there's a chance it was overfilled. A normal cruise shouldn't cause the fluid to get hot enough to spew like that.

I know the previous owner had the hole IRS out to do the full tilt boogie kit and put a FRPP diff cover on, IDK maybe he over filled it, It was leaking when I get the car off the trailer. Ill check the fluid level when I get home.

 

[slseals]

Do you have the stock diff cover? My stock was leaking so I had the FRP cover put on and mine has puked oil since I had it done. I rigged up a longer tube and catch can and its filing up my little can...

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[2011 gtcs]

Do you have the stock diff cover? My stock was leaking so I had the FRP cover put on and mine has puked oil since I had it done. I rigged up a longer tube and catch can and its filing up my little can...

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I don't, the previous might have it but I doubt it. I'll just keep a eye on it

 

[01yellercobra]

When I did my IRS I overfilled it. It leaked out while I was driving it.

 

[BoostedSVT03]

I know the previous owner had the hole IRS out to do the full tilt boogie kit and put a FRPP diff cover on, IDK maybe he over filled it, It was leaking when I get the car off the trailer. Ill check the fluid level when I get home.

The FRPP cover has a fill plug but if you fill it like any normal diff and fill until it runs out, there will be too much oil in there.
I would pull the fill plug and jack the front end up a little to drain the excess off. It will continue to come out the vent tube for a long time and make one hell of a mess.

FYI fill quantity is 1.5 quarts of 75-140 GL-5

 

[MG0h3]

Mine puked a little out of the vent tube when I filled it after the FTBR install and rebuild.

While I was under there doing the fuel system I took a close look and I might have a bit of oil seeping out around a bolt or two and right at the base of the cover. No way Im pulling the cover as it hasnt dripped in a year. Grabbed some SEAL ALL from auto zone for 5 bucks. Its oil and gas resistant. Had a customer with a vette show up with it one day after we diagnosed a leaking diff cover. Labor was like 900 to R&R. His actually had a static leak and to our disbelief that stuff worked.

 

[2011 gtcs]

The FRPP cover has a fill plug but if you fill it like any normal diff and fill until it runs out, there will be too much oil in there.
I would pull the fill plug and jack the front end up a little to drain the excess off. It will continue to come out the vent tube for a long time and make one hell of a mess.

FYI fill quantity is 1.5 quarts of 75-140 GL-5

Thanks for the info, I appreciate it.

 

[fireman02]

Its overfilled. I had the ford racing cover installed last summer, and if I drove normal and kept it under 60-65 I'd have no issues. But if I did some "spirited" driving I'd have a mist of oil under the rear and on the rear bumper from diff oil coming out the vent tube/breather. The shop that installed it said he's noticed he has to put a little less diff fluid in due to this baffling in the new cover. He drained a little and haven't had an issue since.

 

[351stang]

Damn. I'm probably going to have the same problem. I just installed the FR cover and it took like 1.75 quarts.

 

[jrichber]

I had the same problem when I did new cover on last cobra. Looked like the back end of my car got rained on by diff oil. Figured it was leaking so took it apart again and then realized since I had the back jacked all the way up and the front on the floor yet, I was taking almost an extra quart of fluid.

 

[JuStAkId]

When I did my ford racing diff cover I talked to ftbr and he said only 1.3qt or 1.4qt (cant remember exactly) of oil I put around that amount and I have been fine. No oil from the vent tube

Edit: Usually I see people putting 2qt in and thats way too much with the ford racing diff cover. I'd say max 1.5 nothing more. Best bet is there is too much fluid in ur diff

 

[BlksvtCobra01]

Mine does this too and it's a pain in the ass I filled it to the full line. It doesn't do it anymore unless I do some spirited driving. I'm happy I'm not the only one with this issue. What catch can setups are you using.


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[351stang]

I drained 400 ml before I drove it. No leaks. I love this forum.

I didn't drop the exhaust and used a ball head Allen socket and UV joint. I then used a vacuum hand pump to drain the excess. It was a bitch to get the plug back in.

 

[351stang]

:banana: ZERO LEAKS :banana:

I drained 400 ml before I drove it. No leaks. I love this forum.

I didn't drop the exhaust and used a ball head Allen socket and UV joint. I then used a vacuum hand pump to drain the excess. It was a bitch to get the plug back in.