MarkRobinson

On my race car, my S4 gear box rear end cover plate continues to leak. I've drained it 2x & replaced the gaskets but it continues to leak. Anyone else in this boat?

I might have some Buna gaskets made...curious to see how many to make. Tired of it dripping down & at times landing on my lower cars. :/

Mark

WallyP

Did you use RTV on the gasket?

Discovered something interesting a few days ago. GM recommended that you not use synthetic gear oil in the front differential of some of their 4x4 vehicles. Eaton had used RTV rather than a gasket on those models, and synthetic gear oil softens the RTV, resulting in leaks.

I would check the cover for flatness. If it is reasonably flat, perhaps an anaerobic sealer rather than a gasket would do the trick.

MarkRobinson

No, used the OE gaskets both times. :/

Koenig-Specials 928

Mark you sure its not from the half-shaft side that's leaking down? I thought the same thing, replaced the gasket but the leak continued. After washing the area down I found the half shaft on the driver's side leaking. Just a thought.

MarkRobinson

It's leaking from all 3 places: both 1/2 shaft input seals + the rear plate seal. Fun!!

Koenig-Specials 928

I am using Synthetic Gear oil and I used this aircraft type gasket sealer. No leaks in two years.

IcemanG17

I would check how "square" the rear plate and the diff is.....chances are they are slightly out of square over time and this is causing the leak.....a bit of time on a belt sander could square things up quickly....

Mike Simard

Do you have the trans vent sealed off?

The rear cover is no place to put a floppy rubber gasket, it contributes to diff housing strength.
It should be flat enough to nearly seal on it's own.

outbackgeorgia

Hessank,
Used Form-A-Gasket for years! Used as case selant for VW Formula Vee's no issues
This stuff is great, never hardens.
Dave

Jerry Feather

One time I left a tiny piece of the old gasket material on one of the mating surfaces for an oil gallery cover on the back of my airplane engine after an oil change and screen cleaning. I put it back with a new gasket, but by the time I got to the departure end of the runway I was leaving an amazing trail of oil. I don't remember how I discovered it before we took off, but I did, and I was amazed at how much oil was coming out of what was a very tiny resulting defect in the mating surfaces.

MarkRobinson

I need to check the vent: maybe it is closed off: anyone have any experience "checking this"? My car's on my lift, so I have full access.

Mark

Ducman82

isn't the vent just the rubber plug on top?

Mike Simard

You could put a hose on the fill port and see if it holds pressure.

After ruling that out, settle in for some patient gasket surface cleaning and flatness veriffying. A magnifier would help and poking your tounge out adds to the atmosphere of delicateness.

MarkRobinson

nice Mike, my experience has shown that cuss words help as well.

My NOS 928INTL-rebuilt LSD/S4 transaxle might have been shipped with a sealed vent: I'll have to take a look.

Mark

borland

http://www.permatex.com/products/Aut...ge_Sealant.htm