Axle oil and trans fluid

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Blair
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Axle oil and trans fluid

Unread post by Blair » Sun Oct 08, 2017 12:18 pm

Where do I add axle oil and transmission fluid? Is it common or normal for the two to mix and how big of a problem would that be if i discovered it while draining it? Im not positive thats what it is, i just suspect it

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bbodie52
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Re: Axle oil and trans fluid

Unread post by bbodie52 » Sun Oct 08, 2017 4:22 pm

BE SURE TO ONLY FILL YOUR DIFFERENTIAL AND MANUAL TRANSMISSION WITH GL-4 GEAR LUBE. GL-5 gear lube will damage the "yellow metal" components in your manual transmission. The Corvair transaxle shares gear oil between the manual transmission and the differential, so the gear lube must be GL-4 in both.

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The specification section of the shop manual supplement (attached) indicates a rear axle lubricant capacity of 3.1 pints in 1962 models, and 4.5 pints in 1963 models. The same section indicates that the manual three speed transmission has a capacity of 3 pints, and the four speed transmission has a capacity of 3.75 pints. Since the fluid is shared between the transmission and differential, it is important to utilize GL-4 gear lube in both the transmission and the differential. There is a fill plug on the side of the differential and another one on the side of the transmission. Both should be filled to bring the fluid level up to the bottom of the threads before reinstalling each fill plug.

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Manual transmission fill plug is circled in black...
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Attachments
1962-1963 Supplement - Chevrolet Corvair Shop Manual - Section 2 - General Lubrication.pdf
1962-1963 Supplement - Chevrolet Corvair Shop Manual - Section 2 - General Lubrication
(161.33 KiB) Downloaded 4 times
1962-1963 Supplement - Chevrolet Corvair Shop Manual - Section 12 - Specifications.pdf
1962-1963 Supplement - Chevrolet Corvair Shop Manual - Section 12 - Specifications
(626.09 KiB) Downloaded 7 times
1964 Supplement - Chevrolet Corvair Shop Manual - Section 2 - General Lubrication.pdf
1964 Supplement - Chevrolet Corvair Shop Manual - Section 2 - General Lubrication
(134.91 KiB) Downloaded 8 times
Brad Bodie
Lake Chatuge, North Carolina
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Bob Helt
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Re: Axle oil and trans fluid

Unread post by Bob Helt » Mon Oct 30, 2017 11:47 am

Brad is correct for Corvairs with a MANUAL transmissions. Powerglide automatic transmissions do NOT share lube oil and therefore each will have its own different lube.
Bob Helt

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Trip
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Re: Axle oil and trans fluid

Unread post by Trip » Mon Oct 30, 2017 12:03 pm

Just out of curiosity, might bad syncros be the result of a previous owner using GL-5? I'm sure normal wear and tear or abusive drivers also cause bad syncros, just wondering if the wrong lube can as well.
Ray "Trip" Rodriguez III
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bbodie52
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Re: Axle oil and trans fluid

Unread post by bbodie52 » Mon Oct 30, 2017 1:30 pm

The manual transmission synchros are made from the "yellow metal" that GL-5 is apparently capable of damaging. So if someone filled a transaxle with GL-5 gear lube, over time damage would occur. I don't know how long this damage would take... I've never seen any time or mileage estimates.
Brad Bodie
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