Differential Oil Leak..Help.
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 925
Likes: 4
From: EXTON PA
Differential Oil Leak..Help.
I had changed my oil in my stock differential with 2 quarts royal purple and a GM additive. There was some flow that did come out after i filled the gear box. I have had a leak of the fluid at times when I go up or down my driveway that is a 30+ grade. Never oil as a standing puddle in the drive or at a parking stop. Could i have a leak as a result of a over fill or is this a bigger problem. The leak is not all the time and is noticed on my driveway hill.
Thanks for the help
Thanks for the help
Last edited by kg54trains; Jan 11, 2008 at 01:15 PM.
Race Director
Joined: Jul 2004
Posts: 16,795
Likes: 62
From: Lake Havasu City, AZ
The overfill could be leaking from the top of the diff out of the pressure relief valve.
If it has failed in the open position then the angle could be enough either nose up or down to permit the constant leak you see on a steep grade....
Just a thought... but that assumes you have already been under neath it again and ruled out gaskets and output seals and is the only thing I can think of that woul dlead to a leak only on a steep incline or decline
If it has failed in the open position then the angle could be enough either nose up or down to permit the constant leak you see on a steep grade....
Just a thought... but that assumes you have already been under neath it again and ruled out gaskets and output seals and is the only thing I can think of that woul dlead to a leak only on a steep incline or decline
Cruising
Joined: Dec 2005
Posts: 14
Likes: 0
From: Lancaster Pa
Oil Leak
My car is also leaking. Its a 01 Z06, with 30.000 miles. Use the car for trips, autocross and the track several times each summer.
I noticed oil leaking from the left rear side of the axile so I had it checked out. My mechanic told me that when he took the plug out to check the level, air came out, like it was under pressure. The oil that I thought was leaking from a gasket was actually coming out of the pressure relief vent on top of the unit.
He cleaned the valve as best he could, checked the level, but didn't do anything else.
Is it usual to have the pressure build up? Should oil be coming out of the vent?
He didn't change the oil. Should it be changed and should I be using a high performance fluid?
Thanks for any help on this subject....
I noticed oil leaking from the left rear side of the axile so I had it checked out. My mechanic told me that when he took the plug out to check the level, air came out, like it was under pressure. The oil that I thought was leaking from a gasket was actually coming out of the pressure relief vent on top of the unit.
He cleaned the valve as best he could, checked the level, but didn't do anything else.
Is it usual to have the pressure build up? Should oil be coming out of the vent?
He didn't change the oil. Should it be changed and should I be using a high performance fluid?
Thanks for any help on this subject....
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
I was under the impression that air would go in, not out as the relief valve would purge air and not let it back in keeping a slight vacuum on the differential. Not sure if others have information on this.
Tech Contributor
Joined: Jan 2007
Posts: 19,411
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From: Dyer, IN
Melting Slicks
Joined: May 2000
Posts: 2,498
Likes: 4
From: Brentwood TN
Plan on lots of replies extolling the superiority of one brand/color over another and maybe even a couple of insults along the way for someone's choice of one over the other as this topic has been beaten to death, sometimes to the point the mods had to lock the thread.
Never let it be said that a 'Vette owner isn't passionate about his or her toy and the care and feeding thereof.
Charlie
Instructor
Joined: Feb 2007
Posts: 115
Likes: 9
From: Tampa FL
Leak? Maybe not
The best way to find a leak is to squirt the differential with brake cleaner, drive a few days, then take a look. Everything will be nice an shiny except that little drip.
FWIIW, after fixing a differential side cover leak, I drove the car a few weeks, then noticed oil drops on the floor. Damn, I thought it was a re-do. Hate those... Anyway, it turned out that in draining the differential, I filled up the wire shield casing under the differential with oil and it leaked out over time. With a little luck, this could be your cause as well.
FWIIW, after fixing a differential side cover leak, I drove the car a few weeks, then noticed oil drops on the floor. Damn, I thought it was a re-do. Hate those... Anyway, it turned out that in draining the differential, I filled up the wire shield casing under the differential with oil and it leaked out over time. With a little luck, this could be your cause as well.
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Racer
Joined: Jun 2001
Posts: 473
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From: Waterloo Ontario
I hope this helps!
imp.
Safety Car
Joined: Jun 2004
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From: panama city beach florida USA
St. Jude Donor '09
Team Owner
Joined: May 2001
Posts: 87,334
Likes: 1,589
From: Western NY
FWIW, the differential does NOT hold 2 qts. The capacity spec from the shop manual is "1.94 qts.", so if you tried to pump in 2 qts. PLUS the posi additive, you overfilled it.
Don't feel bad, I did it once too...... I filled it right to the fill hole, and it oozed out the vent for a while.
Don't feel bad, I did it once too...... I filled it right to the fill hole, and it oozed out the vent for a while.
Melting Slicks
Joined: Dec 2003
Posts: 3,315
Likes: 17
From: Near Jacksonville Fl.
I found the problem back in 1999 and kepy it at bay by spraying the vent with brake clean and blowing air into the fill hole each year when bringing the car out of storage in Mi.
Now I live in Fl. so the car gets driven all year, just the same when I had the diff out in the spring I also removed the tabs valve and replaced it with a 6" long tube with a normal vent in the end.
Problem solved!
Burning Brakes
Joined: Jun 2006
Posts: 933
Likes: 0
From: St. Paul MN
FWIW, the differential does NOT hold 2 qts. The capacity spec from the shop manual is "1.94 qts.", so if you tried to pump in 2 qts. PLUS the posi additive, you overfilled it.
Don't feel bad, I did it once too...... I filled it right to the fill hole, and it oozed out the vent for a while.
Don't feel bad, I did it once too...... I filled it right to the fill hole, and it oozed out the vent for a while.
However, from what I've read the owners manual says 1.5 quarts and the service manual says 1.69 qts + 4oz of differential fluid (which is exactly what my z06 rearend took before it started spilling out).
