Question about greasy differential
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Joined: Sep 2011
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From: Paris
Question about greasy differential
Hey guys,
Last time I went for a ride I heard for about a minute or two a high pitched noise coming from the back (not very loud), that ceased afterwards. I thought maybe of a stuck caliper but so I went and checked the underside of the car and saw that the part where the sticker "use limited slip lube only" was greasy, and it has dripped a bit on the exhaust pipe. It looks like this:
Do you think I should have it checked out ? I read on this forum that apparently it was a common problem among newer generation C5s.
Thanks
Last time I went for a ride I heard for about a minute or two a high pitched noise coming from the back (not very loud), that ceased afterwards. I thought maybe of a stuck caliper but so I went and checked the underside of the car and saw that the part where the sticker "use limited slip lube only" was greasy, and it has dripped a bit on the exhaust pipe. It looks like this:
Do you think I should have it checked out ? I read on this forum that apparently it was a common problem among newer generation C5s.
Thanks
Race Director
Joined: Feb 2004
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Visual assessment has confirmed a leak in the rear axle assembly, concerning you to the point of making a post on a technical forum.
Your next step is to wipe it down, and see if the leak has decided to stop?
This would involve driving the car (possibly with little or no fluid in the rear) and possibly destroying the rear end assembly?
I would recommend you rethink it, if my observations are correct.
Rear troubles are brutally expensive in the States, and I cannot imagine how expensive it would be overseas.
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From: Paris
Is there a way to add differential fluid or check the level of the fluid by myself ?
I'll take your advice and not drive the car until it is all figured out.
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From: Paris
Gotcha, I'll do this first thing saturday. I found a neat tutorial on how to do this. Just to be sure, the plug to remove is what appears on my 2nd pic (post #1), removable with a 10 mm hex key ?
Thanks for the advice guys !
Thanks for the advice guys !
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Le Mans Master
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From: Tampa Florida
you can do that but if your finger doesn't find fluid use a plastic "tie wrap/zip tie" for some extra reach to see exactly how "low" the oil level is. As mentioned above, if you've got fluid in there I'd spray and wipe the exterior area down then watch and wait for leaks to reform before you dig in. Refill, replace the fluid/pinion seal as needed.Is the rest of the "C" beam that's not pictured oiled up also?
A transmission's output shaft seal can leak and leave a trail of oil all the down the "c" beam and end up on the differential making it look like it has a problem when it doesn't.
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From: Paris
you can do that but if your finger doesn't find fluid use a plastic "tie wrap/zip tie" for some extra reach to see exactly how "low" the oil level is. As mentioned above, if you've got fluid in there I'd spray and wipe the exterior area down then watch and wait for leaks to reform before you dig in. Refill, replace the fluid/pinion seal as needed.Is the rest of the "C" beam that's not pictured oiled up also?
A transmission's output shaft seal can leak and leave a trail of oil all the down the "c" beam and end up on the differential making it look like it has a problem when it doesn't.
Fill it with 75-90 or whatever the guys are using these days.
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Good advice everyone has for you.
If the rest of the underside of your car is dry forward of the rear differential of oil residue,
then the oil leak is most likely from the rear differential.
It looks like a classic case of the front side rear differential pinion oil seal leaking to me from your pics.
It can be repaired in the vehicle with TLC used and skill on your part.
If the rear stub shaft oil seals are leaking,
differential assembly removal from your Corvette will be required to remove the inner drive stub shaft snap rings with heavy duty snap ring pliers.
Many would let the oil leak go & run it till it dies as most choose to do with their daily driver vehicles today.....
Be best to make necessary repairs as required.
You can do repairs yourself at home if you have right tools & patience & handy skills.
The factory nitrile rubber oil seals made by CR or National oil seals were designed to last 20 years on the parts shelf or in daily service installed in a vehicles differential.
Your 1987 c4 is just about 25 years old as my 87 vert.
Served a long life holding 75-90w gear oil fluid inside.
BR
If the rest of the underside of your car is dry forward of the rear differential of oil residue,
then the oil leak is most likely from the rear differential.
It looks like a classic case of the front side rear differential pinion oil seal leaking to me from your pics.
It can be repaired in the vehicle with TLC used and skill on your part.
If the rear stub shaft oil seals are leaking,
differential assembly removal from your Corvette will be required to remove the inner drive stub shaft snap rings with heavy duty snap ring pliers.
Many would let the oil leak go & run it till it dies as most choose to do with their daily driver vehicles today.....
Be best to make necessary repairs as required.
You can do repairs yourself at home if you have right tools & patience & handy skills.
The factory nitrile rubber oil seals made by CR or National oil seals were designed to last 20 years on the parts shelf or in daily service installed in a vehicles differential.
Your 1987 c4 is just about 25 years old as my 87 vert.
Served a long life holding 75-90w gear oil fluid inside.
BR
Safety Car
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My drain/fill plug leaks as well. I'm going to use some liquid thread sealant. I figure if that gets in the oil, then it would be better than if tape particles got in the oil.
