Oil Pan and Differential Gasket Questions

[Jocko_51_B3B]

 

Oil Pan Gasket Question...

What is the best sealant to use when installing cork gaskets? I've read other posts that clearly explain how to arrange the side and end gaskets on the oil pan, but what sealant product is best used with cork gaskets for holding the oil pan gaskets onto the pan as the bolts are torqued? Permatex makes red, black, blue etc. kinds of gasket makers in tubes along with a whole bunch of other products. And what is best applied to the block side of the oil pan gasket? I've heard that some people use vaseline.

Differential Gasket Question...

Also, I carefully cut out a new gasket for the differential and I have similar questions regarding it. Can I use the same sealants as are used on the oil pan?

[NiftyFifty]

I'm a big fan of aviation gasket maker:  https://www.permatex.com/products/gasketing/gasket-sealants/permatex-aviation-form-a-gasket-no-3-sealant-liquid/

 

works great for oil pans and no reason it won't work on the diff cover.  I usually just use ultra black or blue of diff covers, no gaskets, but on the original style diff it may be a bit more necessary then on the Dana axles

[Merle Coggins]

I don't believe I would use a cork gasket for the diff mount. You want a good metal to metal mount there as there is potential for movement from the torque applied to it. I would just use a small bead of RTV silicone for that. Or even better, one of Permetex's Anerobic gasket makers / flange sealers. They will cure hard and make a good seal. https://www.permatex.com/products/gasketing/anaerobic-gasket-makers-flange-sealants/permatex-anaerobic-gasket-maker/

 

[PT81Jan]

I have made pretty good experience with copper gasket cement spray.
(The spray is applied to the gasket itself plus to the sealing surfaces. It doesn`t replace the gasket)

It gives a perfect sealing with the advantage that it is very easy to remove a gasket (cork, paper, metal) if necessary. I have used it for the oil pan cork gasket as well as for other gaskets like the gear case cover and cylinder head.

Example: Some years ago I had trouble to get a durable sealing of a flathead`s cylinder head (aluminum head, iron block, copper gasket) although the surfaces where perfect in shape. Due to the different coefficient of thermal expansion there was a slight move between the parts which regularly led to leakage. After using the copper gasket spray I never had trouble again with it.

http://www.vhtpaint.com/specialty/vht-copper-gasket-cement

 

BTW: I agree to Merle. I also would use a silicon sealer or something like that for the rear end, since it normally seldom has to be replaced and it also gives a reliable sealing.

Edited June 9, 2017 by PT81Jan

[Jocko_51_B3B]

You guys have pretty well convinced me to abandon my beautiful cork differential gasket and just use a sealer. But what about the block side of the oil pan gasket? I could use sealer on both sides of that gasket, but it seems like a good idea to use something that won't cause the gasket to be destroyed if I remove the pan for some reason.

[PT81Jan]

I am sorry if I have to disappoint you. I am afraid that you have to use a new gasket all the time,  if you have to remove the pan. The cork is compressed due to the installation, so I doubt it would give a good sealing a second time anyway.  I bought a big cork plate and cut out some gaskets more for that reason,  so it is not too much effort and costs. 

[PT81Jan]

Ah,  and regarding your neat differential gasket - don 't let our suggestions stop you to install it. Test it and let us know your experience 

[JBNeal]

additional information - Grease Selection Chart 

Edited October 18, 2019 by JBNeal
revised link

[Young Ed]

I believe the OEM install used a gasket. I've got gaskets on both my diffs. I don't believe that's one of the places that leaks....

[bambamshere]

I just install my oil pan gasket yesterday. It was cork. I put a small bead of permatex ultra black. Put oil in it today and it is holding. For dif I would use a metal gasket for it easier to take off if needed.

[NiftyFifty]

From experience, ultra black on an oil pan with cork gaskets can leak if your using it between the pan and gasket and the gasket and block....had to get a whole new gasket for my Monaco because it leaked right away

[bambamshere]

I used it on mine seams to be holding. Did you wait the 24hrs after torquing the bolts to put oil into it. 

[bambamshere]

I didn't use it between gasket and block. Just between pan and gasket and made sure I went around each bolt hole. 

[NiftyFifty]

I used it on the pan liberally and just a very thin layer between gasket and block..let it set up but leaked ...not sure why, but it doesn't play well with the cork I guess.  Maybe I just got unlucky, but I stick to the aviation sealer now

[Dave72dt]

Permatex makes a sealer specifically for rear end grease, comes in a green colored tube.  Silicone used as a sealer should be applied sparingly.  Silicone as a gasket is applied differently and has a cure time before components are to be married together.  Most of the silicone I've seen used by manufacturers has been black, apllied very sparingly.  I personally avoid silicones if I can, prefer to use Aviation and sometimes the old fashioned green non-hardening Permatex in a tube.

[Jocko_51_B3B]

I contacted Permatex through their website and asked about their Gear Oil RTV (in the green tube) to seal my differential. Here is their reply...

"Our Gear Oil RTV can be used alone as a gasket maker or as a dressing on a cut gasket if you wish to use one in your application."

[Jocko_51_B3B]

The cork gasket on the differential didn't work out. I used Permatex Ultra Black Gasket Maker on the axle assembly and on the differential and then installed the gasket, but when I torqued the nuts, the gasket squeezed out. I could see that the cork gasket wasn't going to work out so I removed it and used the Permatex Ultra Black alone to seal the differential. I added oil ten days ago and so far no leaks.

Edited June 30, 2017 by Jocko_51_B3B
better wording

[NiftyFifty]

Best way to go, cork and rtv don't mix in my experience.  All you need is about 12 hours before oil, but honestly back in my shop days, we would wait maybe an hour, then fill and 99.99% never came back.