GCG

I am attempting to do this now. I have the car in my garage up in ramps and jack stands. My intention is to do what Lowvette did and just remove the cap and replace the spring and rubber disk and then pop the cap back on.

I have a question for you guys, as I have never messed around with the exhaust pipes before: is it possible to remove the rear section of the exhaust pipes without lowering the cradle while working on jack stands?

HardcoreABN

Going to try this myself....on the dyno I could see fluid getting pushed out of pretty much every seal on my diff lol....

GCG

OK, I came back to report: success!!!

In relation to my prior message regarding the exhaust pipes, I found this thread that pretty much answered my questions about this matter. So "NO" to completely remove the exhaust.

I did not want to get into the business of lowering the cradle, unless it was mandatory, so what I did was to unbolt the rear flange and freed the rear portion of the left exhaust to give me some flexibility around the working area.

I already had the new vent dismantled, so I had gained some "experience" in the process and went ahead and carefully did the same with my differential vent. I could get both of my arms up there, but I was basically working blind. Everything went beautifully.

I have to confirm what Lowvette reported: the internal rubber seal was malformed into a concave shape, similar to a contact lens although not that bad. The new rubber seal was perfectly flat.

I cleaned everything around the vent, and using the new spring and seal along with my old cap (it was in better shape than the new one: basically looked untouched after I removed) I quickly popped the assembly right back and reattached the exhaust pipes

I'll report back how it goes, but considering the good results that Lowvette obtained, I'm confident it should be fine If that's the case, I think going this route instead of attaching a foot of hose and a vent at its end, as per GM's bulleting, is the way to go.

GCG

Another thing that I forgot to mention: the Mopar vent is exactly the same as ours at 1/3 the cost

ZeeOSix

If the new seal was also rubber like the old one, then it will probably go bad after some time also. As I mentioned in one of my posts earlier in this thread, the rubber seal seems to stick to the top of the vent nipple, and that's what causes the pressure to build-up and then cause the differential to puke oil. If the seal was made out of a disk of teflon, it would be a better design IMO.

I was able to get a piece of 5/16” ID fuel line and metal hose clamp on the differential nipple without removing any exhaust pipe ... it wasn't easy (probably 30~45 min of cussing), but I eventually got it on there.

corvettebob1

You are correct, replacing the seal and spring is a waste of time and effort. You have 2 things working against you heat and vacuum this will deform the seal and cause it to stick building pressure inside the diff.
Open breathers work perfectly and have been for over 100 years!

Bigfoot99

Re-resurrecting this thread again. ��

I'm in the process of doing this now. Used 3/8" fuel line hose and ordered the part. I know a breather can be used, but if it starts again, I'll just switch to a breather.

One question though. Has anyone had any trouble with the hose popping off the nipple on the diff? I think mine is on fairly solid now, but at first it would keep slipping off. I've got it zip tied up and ready to go. Also, do you guys have the free end of the hose pointing up or down...or does it matter?

froggy47

rodsvet

Chevy has known of this problem for at least 15 years. A few months after buying my 2000, this problem started. I took it to the dealer and they did the hose trick under warranty. No problem since (15 years and counting).

froggy47

Would you guys begrudge GM saving 50 cents on every Vette, come on.

topdown01

Another resurrection...sorry, just wanted to report that I was able to get a chisel between the vent lip and the case...a little tapping, not too hard so I would not damage anything...after I raised the vent a little I was able to use a pry point and a hammer to raise the vent from the hole completely. No issues occurred, installed the new vent with a 14mm deep socket. Note, I had the rear end out of the car to replace a clutch and the fix the leaky butt.



Kevin

GCG

Did you take pictures?

tungstenfoot

Happy to see this thread resurrected... I'm fairly certain I need to replace my driver axle seal, BUT it seems this diff vent is contributing to the seal leak as well.

I am going to do this vent mod/overhaul while I'm in there. I'll get some pics the best I can.

Is it better to use 5/16" or 3/8" hose?

Bill Curlee

As long as the diff can vent, I dont think it matters. The area where I live (North East) we have an insect that lays eggs and builds a dirt nest in any opening like a VENT HOSE.

GM had a recall a while back on some cars to correct an issue with a fuel system vent that the bugs would cloogg up.

Just saying

Bill

If it were me, I would put a small course grid screen over the opening just to be on the safe side...

tungstenfoot

I had my driver diff cover off today replacing cover oring and axle seal. While there i had decent access to the diff vent for inspection. After removing the vent cap, spring and rubber disc I measured the OD of the remaining pressed in piece in the diff and got dia .40 inches.
I think you can make a 3/8" hose connection work here but i felt there wasnt much length (or room) to get a secure connection... so i reformed the crimp on the vent cap and popped it back on without the spring or rubber seal. I looked around the web and this seemed like the best overall solution to me.

JMB47

I know this is an old post but I was wondering, can fluid come out of the diff vent to the point that it could leave a mist on the rear bumper? With out climbing under, I'm trying to establish if it's my vent or perhaps a seal!

RMBLROAR

Probably not the vent....

corvettebob1

Yes it can in fact that is exactly how I found my vent leak.

JMB47

I appreciate the quick response from both RMBLROAR and corvettebob1. I'm trying to establish where my leak is before go to my local Chevy dealer which I know won't be cheap but at this point it's my only option since I don't know of any reputable corvette technician in the Hernando County Florida area, and being very picky about my car, I'm sure you understand! Time to climb under and check it out! Thanks guys

GCG