Core plug leaking...

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acarlson
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Core plug leaking...

Post by acarlson »

I have transmission fluid seeping out of what I think are core plugs (freeze plugs) in the front of my '66 4 speed transmission case. See picture below:
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I'd rather not pull them out of the case. My other option is to seal cavity on the end of the plug. Has anyone ever done this successfully ?? I

I'm not a real fan of ATV, but Permatex Ultra Black claims it is oil proof and reviewers of the product claim success using it as a gasket searler on oil pans and differentials.

Any thoughts on solving this problem ??

Alec
Alec Carlson
Dahlonega, GA
1965 Regal Red Corsa 4 Speed Turbo Convertible
Restoration "In Progress"...
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azdave
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Re: Core plug leaking...

Post by azdave »

It does seem low-risk and low-hassle to attempt to seal them externally with a name-brand RTV such as Permatex. That is what I would do after a very through cleaning with a small wire wheel, brass brush and brake cleaner spray or such. I would only apply minimal RTV so that it cures faster than applying a big thick glop.
Dave W. from Gilbert, AZ

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Jerry Whitt
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Re: Core plug leaking...

Post by Jerry Whitt »

The term "freeze plug" was INCORRECTLY used to explain that when coolant, or water would freeze, and in that process expand, causing breakage of various cast iron parts, the plug would pop out and therefore, in theory, release pressure, preventing cracked blocks. In actuality, ice does not work like hydraulics and pressure would not be released.

The term "core plug" is more accurate. Various parts are made from very hot liquid metal pored over sand castings. After cooling, the sand has to be removed and is done through the core plug holes or casting holes.
Jerry Whitt
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acarlson
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Re: Core plug leaking...

Post by acarlson »

Ahh, yes Jerry - you are correct.

But I'm an "old school" guy and freeze plug was what I called them in 1968. I know Core Plug is the correct term but I wasn't sure if everyone knew that so I added the "freeze Plug" comment just in case..

Alec
Alec Carlson
Dahlonega, GA
1965 Regal Red Corsa 4 Speed Turbo Convertible
Restoration "In Progress"...
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bbodie52
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Re: Core plug leaking...

Post by bbodie52 »

I've never dismantled a 1966 manual transmission, but those "Core Plugs" might actually be the ends of the Counter Gear Shaft (7) and the Reverse Idler Shaft (5) shown in the illustrations from Clark's Corvair Parts. I don't know how to seal them, but I don't think they are just case plugs.


Left-click once or twice to enlarge the images for better viewing...
1966 Transmission (1).jpg
1966 Transmission (2).jpg
Image

Are you sure that the gear lube is not seeping from the Front End Cover (12) or the Gear Selector Shaft (10)?

If you need assistance from a professional mechanic with Corvair transmission experience, you might contact Avery Corvairs in Campobello, SC (about 144 miles from Dahlonega, GA).

:link: http://averycorvairs.com/transmissions- ... nsaxl.html

Avery Corvairs
1410 Holly Springs Church Rd
Campobello, SC 29322
828-342-0953

Vairtech@yahoo.com
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible
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acarlson
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Re: Core plug leaking...

Post by acarlson »

Brad, You may be correct but if they are a shaft that moves within the transmission, there would be seals around them and none are specified for those holes. It is possible that the shafts you refer to are supported within those holes and the plugs are the "seal". In any case they are leaking. I've sprayed them clean with brake cleaner. They are dry when I'm done. 24 hours later there is a slight oil deposit in the bottom of the hole. It is not coming from the end cover and definitely not the shift shaft.

I appreciate the reference to Avery Corvairs. I've actually tried to contact them a couple of times. Got their information from the Corsa newsletters. Left them voice mail a few times. They never returned my calls so I gave up on them.

Alec
Alec Carlson
Dahlonega, GA
1965 Regal Red Corsa 4 Speed Turbo Convertible
Restoration "In Progress"...
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bbodie52
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Re: Core plug leaking...

Post by bbodie52 »

I believe those shafts are rigidly mounted and do not move during transmission operation. The gears and bearings rotate on the fixed shafts.

That phone number is for a cell phone with a North Carolina area code. You might try an email message. Perhaps they have experience in dealing with seepage from those shafts.
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible
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